Merge pull request #2267 from dead10ck/fix-write-fail

Write path fixes

23 files changed, 995 insertions, 298 deletions

diff --git a/docs/CONTRIBUTING.md b/docs/CONTRIBUTING.md
index 353cb4fd..491cd424 100644
--- a/docs/CONTRIBUTING.md
+++ b/docs/CONTRIBUTING.md
@@ -35,7 +35,8 @@ to `cargo install` anything either).
 Integration tests for helix-term can be run with `cargo integration-test`. Code
 contributors are strongly encouraged to write integration tests for their code.
 Existing tests can be used as examples. Helpers can be found in
-[helpers.rs][helpers.rs]
+[helpers.rs][helpers.rs]. The log level can be set with the `HELIX_LOG_LEVEL`
+environment variable, e.g. `HELIX_LOG_LEVEL=debug cargo integration-test`.
 
 ## Minimum Stable Rust Version (MSRV) Policy
 
diff --git a/helix-core/src/auto_pairs.rs b/helix-core/src/auto_pairs.rs
index ff680a77..edc404ac 100644
--- a/helix-core/src/auto_pairs.rs
+++ b/helix-core/src/auto_pairs.rs
@@ -7,7 +7,6 @@ use std::collections::HashMap;
 use smallvec::SmallVec;
 
 // Heavily based on https://github.com/codemirror/closebrackets/
-
 pub const DEFAULT_PAIRS: &[(char, char)] = &[
     ('(', ')'),
     ('{', '}'),
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index b5083f55..a08e5084 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -61,6 +61,12 @@ pub struct Configuration {
     pub language: Vec<LanguageConfiguration>,
 }
 
+impl Default for Configuration {
+    fn default() -> Self {
+        crate::config::default_syntax_loader()
+    }
+}
+
 // largely based on tree-sitter/cli/src/loader.rs
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 4bb36b59..b4b4a675 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -1,12 +1,19 @@
 use arc_swap::{access::Map, ArcSwap};
 use futures_util::Stream;
 use helix_core::{
-    config::{default_syntax_loader, user_syntax_loader},
     diagnostic::{DiagnosticTag, NumberOrString},
+    path::get_relative_path,
     pos_at_coords, syntax, Selection,
 };
 use helix_lsp::{lsp, util::lsp_pos_to_pos, LspProgressMap};
-use helix_view::{align_view, editor::ConfigEvent, theme, tree::Layout, Align, Editor};
+use helix_view::{
+    align_view,
+    document::DocumentSavedEventResult,
+    editor::{ConfigEvent, EditorEvent},
+    theme,
+    tree::Layout,
+    Align, Editor,
+};
 use serde_json::json;
 
 use crate::{
@@ -19,7 +26,7 @@ use crate::{
     ui::{self, overlay::overlayed},
 };
 
-use log::{error, warn};
+use log::{debug, error, warn};
 use std::{
     io::{stdin, stdout, Write},
     sync::Arc,
@@ -102,7 +109,11 @@ fn restore_term() -> Result<(), Error> {
 }
 
 impl Application {
-    pub fn new(args: Args, config: Config) -> Result<Self, Error> {
+    pub fn new(
+        args: Args,
+        config: Config,
+        syn_loader_conf: syntax::Configuration,
+    ) -> Result<Self, Error> {
         #[cfg(feature = "integration")]
         setup_integration_logging();
 
@@ -129,14 +140,6 @@ impl Application {
             })
             .unwrap_or_else(|| theme_loader.default_theme(true_color));
 
-        let syn_loader_conf = user_syntax_loader().unwrap_or_else(|err| {
-            eprintln!("Bad language config: {}", err);
-            eprintln!("Press <ENTER> to continue with default language config");
-            use std::io::Read;
-            // This waits for an enter press.
-            let _ = std::io::stdin().read(&mut []);
-            default_syntax_loader()
-        });
         let syn_loader = std::sync::Arc::new(syntax::Loader::new(syn_loader_conf));
 
         let mut compositor = Compositor::new().context("build compositor")?;
@@ -245,6 +248,10 @@ impl Application {
         Ok(app)
     }
 
+    #[cfg(feature = "integration")]
+    fn render(&mut self) {}
+
+    #[cfg(not(feature = "integration"))]
     fn render(&mut self) {
         let compositor = &mut self.compositor;
 
@@ -275,9 +282,6 @@ impl Application {
     where
         S: Stream<Item = crossterm::Result<crossterm::event::Event>> + Unpin,
     {
-        #[cfg(feature = "integration")]
-        let mut idle_handled = false;
-
         loop {
             if self.editor.should_close() {
                 return false;
@@ -294,26 +298,6 @@ impl Application {
                 Some(signal) = self.signals.next() => {
                     self.handle_signals(signal).await;
                 }
-                Some((id, call)) = self.editor.language_servers.incoming.next() => {
-                    self.handle_language_server_message(call, id).await;
-                    // limit render calls for fast language server messages
-                    let last = self.editor.language_servers.incoming.is_empty();
-
-                    if last || self.last_render.elapsed() > LSP_DEADLINE {
-                        self.render();
-                        self.last_render = Instant::now();
-                    }
-                }
-                Some(payload) = self.editor.debugger_events.next() => {
-                    let needs_render = self.editor.handle_debugger_message(payload).await;
-                    if needs_render {
-                        self.render();
-                    }
-                }
-                Some(config_event) = self.editor.config_events.1.recv() => {
-                    self.handle_config_events(config_event);
-                    self.render();
-                }
                 Some(callback) = self.jobs.futures.next() => {
                     self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
                     self.render();
@@ -322,26 +306,22 @@ impl Application {
                     self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
                     self.render();
                 }
-                _ = &mut self.editor.idle_timer => {
-                    // idle timeout
-                    self.editor.clear_idle_timer();
-                    self.handle_idle_timeout();
+                event = self.editor.wait_event() => {
+                    let _idle_handled = self.handle_editor_event(event).await;
 
                     #[cfg(feature = "integration")]
                     {
-                        idle_handled = true;
+                        if _idle_handled {
+                            return true;
+                        }
                     }
                 }
             }
 
             // for integration tests only, reset the idle timer after every
-            // event to make a signal when test events are done processing
+            // event to signal when test events are done processing
             #[cfg(feature = "integration")]
             {
-                if idle_handled {
-                    return true;
-                }
-
                 self.editor.reset_idle_timer();
             }
         }
@@ -446,6 +426,111 @@ impl Application {
         }
     }
 
+    pub fn handle_document_write(&mut self, doc_save_event: DocumentSavedEventResult) {
+        let doc_save_event = match doc_save_event {
+            Ok(event) => event,
+            Err(err) => {
+                self.editor.set_error(err.to_string());
+                return;
+            }
+        };
+
+        let doc = match self.editor.document_mut(doc_save_event.doc_id) {
+            None => {
+                warn!(
+                    "received document saved event for non-existent doc id: {}",
+                    doc_save_event.doc_id
+                );
+
+                return;
+            }
+            Some(doc) => doc,
+        };
+
+        debug!(
+            "document {:?} saved with revision {}",
+            doc.path(),
+            doc_save_event.revision
+        );
+
+        doc.set_last_saved_revision(doc_save_event.revision);
+
+        let lines = doc_save_event.text.len_lines();
+        let bytes = doc_save_event.text.len_bytes();
+
+        if doc.path() != Some(&doc_save_event.path) {
+            if let Err(err) = doc.set_path(Some(&doc_save_event.path)) {
+                log::error!(
+                    "error setting path for doc '{:?}': {}",
+                    doc.path(),
+                    err.to_string(),
+                );
+
+                self.editor.set_error(err.to_string());
+                return;
+            }
+
+            let loader = self.editor.syn_loader.clone();
+
+            // borrowing the same doc again to get around the borrow checker
+            let doc = doc_mut!(self.editor, &doc_save_event.doc_id);
+            let id = doc.id();
+            doc.detect_language(loader);
+            let _ = self.editor.refresh_language_server(id);
+        }
+
+        // TODO: fix being overwritten by lsp
+        self.editor.set_status(format!(
+            "'{}' written, {}L {}B",
+            get_relative_path(&doc_save_event.path).to_string_lossy(),
+            lines,
+            bytes
+        ));
+    }
+
+    #[inline(always)]
+    pub async fn handle_editor_event(&mut self, event: EditorEvent) -> bool {
+        log::debug!("received editor event: {:?}", event);
+
+        match event {
+            EditorEvent::DocumentSaved(event) => {
+                self.handle_document_write(event);
+                self.render();
+            }
+            EditorEvent::ConfigEvent(event) => {
+                self.handle_config_events(event);
+                self.render();
+            }
+            EditorEvent::LanguageServerMessage((id, call)) => {
+                self.handle_language_server_message(call, id).await;
+                // limit render calls for fast language server messages
+                let last = self.editor.language_servers.incoming.is_empty();
+
+                if last || self.last_render.elapsed() > LSP_DEADLINE {
+                    self.render();
+                    self.last_render = Instant::now();
+                }
+            }
+            EditorEvent::DebuggerEvent(payload) => {
+                let needs_render = self.editor.handle_debugger_message(payload).await;
+                if needs_render {
+                    self.render();
+                }
+            }
+            EditorEvent::IdleTimer => {
+                self.editor.clear_idle_timer();
+                self.handle_idle_timeout();
+
+                #[cfg(feature = "integration")]
+                {
+                    return true;
+                }
+            }
+        }
+
+        false
+    }
+
     pub fn handle_terminal_events(&mut self, event: Result<CrosstermEvent, crossterm::ErrorKind>) {
         let mut cx = crate::compositor::Context {
             editor: &mut self.editor,
@@ -866,11 +951,10 @@ impl Application {
 
         self.event_loop(input_stream).await;
 
-        let err = self.close().await.err();
-
+        let close_errs = self.close().await;
         restore_term()?;
 
-        if let Some(err) = err {
+        for err in close_errs {
             self.editor.exit_code = 1;
             eprintln!("Error: {}", err);
         }
@@ -878,13 +962,33 @@ impl Application {
         Ok(self.editor.exit_code)
     }
 
-    pub async fn close(&mut self) -> anyhow::Result<()> {
-        self.jobs.finish().await?;
+    pub async fn close(&mut self) -> Vec<anyhow::Error> {
+        // [NOTE] we intentionally do not return early for errors because we
+        //        want to try to run as much cleanup as we can, regardless of
+        //        errors along the way
+        let mut errs = Vec::new();
+
+        if let Err(err) = self
+            .jobs
+            .finish(&mut self.editor, Some(&mut self.compositor))
+            .await
+        {
+            log::error!("Error executing job: {}", err);
+            errs.push(err);
+        };
+
+        if let Err(err) = self.editor.flush_writes().await {
+            log::error!("Error writing: {}", err);
+            errs.push(err);
+        }
 
         if self.editor.close_language_servers(None).await.is_err() {
             log::error!("Timed out waiting for language servers to shutdown");
-        };
+            errs.push(anyhow::format_err!(
+                "Timed out waiting for language servers to shutdown"
+            ));
+        }
 
-        Ok(())
+        errs
     }
 }
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 5073651b..87bbd6c6 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -47,12 +47,13 @@ use movement::Movement;
 use crate::{
     args,
     compositor::{self, Component, Compositor},
+    job::Callback,
     keymap::ReverseKeymap,
     ui::{self, overlay::overlayed, FilePicker, Picker, Popup, Prompt, PromptEvent},
 };
 
-use crate::job::{self, Job, Jobs};
-use futures_util::{FutureExt, StreamExt};
+use crate::job::{self, Jobs};
+use futures_util::StreamExt;
 use std::{collections::HashMap, fmt, future::Future};
 use std::{collections::HashSet, num::NonZeroUsize};
 
@@ -107,10 +108,11 @@ impl<'a> Context<'a> {
         let callback = Box::pin(async move {
             let json = call.await?;
             let response = serde_json::from_value(json)?;
-            let call: job::Callback =
-                Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
+            let call: job::Callback = Callback::EditorCompositor(Box::new(
+                move |editor: &mut Editor, compositor: &mut Compositor| {
                     callback(editor, compositor, response)
-                });
+                },
+            ));
             Ok(call)
         });
         self.jobs.callback(callback);
@@ -1925,8 +1927,8 @@ fn global_search(cx: &mut Context) {
     let show_picker = async move {
         let all_matches: Vec<FileResult> =
             UnboundedReceiverStream::new(all_matches_rx).collect().await;
-        let call: job::Callback =
-            Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
+        let call: job::Callback = Callback::EditorCompositor(Box::new(
+            move |editor: &mut Editor, compositor: &mut Compositor| {
                 if all_matches.is_empty() {
                     editor.set_status("No matches found");
                     return;
@@ -1962,7 +1964,8 @@ fn global_search(cx: &mut Context) {
                     },
                 );
                 compositor.push(Box::new(overlayed(picker)));
-            });
+            },
+        ));
         Ok(call)
     };
     cx.jobs.callback(show_picker);
@@ -2504,13 +2507,6 @@ fn insert_at_line_end(cx: &mut Context) {
     doc.set_selection(view.id, selection);
 }
 
-/// Sometimes when applying formatting changes we want to mark the buffer as unmodified, for
-/// example because we just applied the same changes while saving.
-enum Modified {
-    SetUnmodified,
-    LeaveModified,
-}
-
 // Creates an LspCallback that waits for formatting changes to be computed. When they're done,
 // it applies them, but only if the doc hasn't changed.
 //
@@ -2519,11 +2515,12 @@ enum Modified {
 async fn make_format_callback(
     doc_id: DocumentId,
     doc_version: i32,
-    modified: Modified,
     format: impl Future<Output = Result<Transaction, FormatterError>> + Send + 'static,
+    write: Option<(Option<PathBuf>, bool)>,
 ) -> anyhow::Result<job::Callback> {
-    let format = format.await?;
-    let call: job::Callback = Box::new(move |editor, _compositor| {
+    let format = format.await;
+
+    let call: job::Callback = Callback::Editor(Box::new(move |editor| {
         if !editor.documents.contains_key(&doc_id) {
             return;
         }
@@ -2531,22 +2528,30 @@ async fn make_format_callback(
         let scrolloff = editor.config().scrolloff;
         let doc = doc_mut!(editor, &doc_id);
         let view = view_mut!(editor);
-        if doc.version() == doc_version {
-            apply_transaction(&format, doc, view);
-            doc.append_changes_to_history(view.id);
-            doc.detect_indent_and_line_ending();
-            view.ensure_cursor_in_view(doc, scrolloff);
-            if let Modified::SetUnmodified = modified {
-                doc.reset_modified();
+
+        if let Ok(format) = format {
+            if doc.version() == doc_version {
+                apply_transaction(&format, doc, view);
+                doc.append_changes_to_history(view.id);
+                doc.detect_indent_and_line_ending();
+                view.ensure_cursor_in_view(doc, scrolloff);
+            } else {
+                log::info!("discarded formatting changes because the document changed");
             }
-        } else {
-            log::info!("discarded formatting changes because the document changed");
         }
-    });
+
+        if let Some((path, force)) = write {
+            let id = doc.id();
+            if let Err(err) = editor.save(id, path, force) {
+                editor.set_error(format!("Error saving: {}", err));
+            }
+        }
+    }));
+
     Ok(call)
 }
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 pub enum Open {
     Below,
     Above,
diff --git a/helix-term/src/commands/dap.rs b/helix-term/src/commands/dap.rs
index 12a3fbc7..c27417e3 100644
--- a/helix-term/src/commands/dap.rs
+++ b/helix-term/src/commands/dap.rs
@@ -118,11 +118,14 @@ fn dap_callback<T, F>(
     let callback = Box::pin(async move {
         let json = call.await?;
         let response = serde_json::from_value(json)?;
-        let call: Callback = Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
-            callback(editor, compositor, response)
-        });
+        let call: Callback = Callback::EditorCompositor(Box::new(
+            move |editor: &mut Editor, compositor: &mut Compositor| {
+                callback(editor, compositor, response)
+            },
+        ));
         Ok(call)
     });
+
     jobs.callback(callback);
 }
 
@@ -274,10 +277,11 @@ pub fn dap_launch(cx: &mut Context) {
             let completions = template.completion.clone();
             let name = template.name.clone();
             let callback = Box::pin(async move {
-                let call: Callback = Box::new(move |_editor, compositor| {
-                    let prompt = debug_parameter_prompt(completions, name, Vec::new());
-                    compositor.push(Box::new(prompt));
-                });
+                let call: Callback =
+                    Callback::EditorCompositor(Box::new(move |_editor, compositor| {
+                        let prompt = debug_parameter_prompt(completions, name, Vec::new());
+                        compositor.push(Box::new(prompt));
+                    }));
                 Ok(call)
             });
             cx.jobs.callback(callback);
@@ -332,10 +336,11 @@ fn debug_parameter_prompt(
                 let config_name = config_name.clone();
                 let params = params.clone();
                 let callback = Box::pin(async move {
-                    let call: Callback = Box::new(move |_editor, compositor| {
-                        let prompt = debug_parameter_prompt(completions, config_name, params);
-                        compositor.push(Box::new(prompt));
-                    });
+                    let call: Callback =
+                        Callback::EditorCompositor(Box::new(move |_editor, compositor| {
+                            let prompt = debug_parameter_prompt(completions, config_name, params);
+                            compositor.push(Box::new(prompt));
+                        }));
                     Ok(call)
                 });
                 cx.jobs.callback(callback);
@@ -582,7 +587,7 @@ pub fn dap_edit_condition(cx: &mut Context) {
             None => return,
         };
         let callback = Box::pin(async move {
-            let call: Callback = Box::new(move |editor, compositor| {
+            let call: Callback = Callback::EditorCompositor(Box::new(move |editor, compositor| {
                 let mut prompt = Prompt::new(
                     "condition:".into(),
                     None,
@@ -610,7 +615,7 @@ pub fn dap_edit_condition(cx: &mut Context) {
                     prompt.insert_str(&condition, editor)
                 }
                 compositor.push(Box::new(prompt));
-            });
+            }));
             Ok(call)
         });
         cx.jobs.callback(callback);
@@ -624,7 +629,7 @@ pub fn dap_edit_log(cx: &mut Context) {
             None => return,
         };
         let callback = Box::pin(async move {
-            let call: Callback = Box::new(move |editor, compositor| {
+            let call: Callback = Callback::EditorCompositor(Box::new(move |editor, compositor| {
                 let mut prompt = Prompt::new(
                     "log-message:".into(),
                     None,
@@ -651,7 +656,7 @@ pub fn dap_edit_log(cx: &mut Context) {
                     prompt.insert_str(&log_message, editor);
                 }
                 compositor.push(Box::new(prompt));
-            });
+            }));
             Ok(call)
         });
         cx.jobs.callback(callback);
diff --git a/helix-term/src/commands/typed.rs b/helix-term/src/commands/typed.rs
index 13a0adcf..f20e71c2 100644
--- a/helix-term/src/commands/typed.rs
+++ b/helix-term/src/commands/typed.rs
@@ -1,5 +1,7 @@
 use std::ops::Deref;
 
+use crate::job::Job;
+
 use super::*;
 
 use helix_view::{
@@ -19,6 +21,8 @@ pub struct TypableCommand {
 }
 
 fn quit(cx: &mut compositor::Context, args: &[Cow<str>], event: PromptEvent) -> anyhow::Result<()> {
+    log::debug!("quitting...");
+
     if event != PromptEvent::Validate {
         return Ok(());
     }
@@ -30,6 +34,7 @@ fn quit(cx: &mut compositor::Context, args: &[Cow<str>], event: PromptEvent) ->
         buffers_remaining_impl(cx.editor)?
     }
 
+    cx.block_try_flush_writes()?;
     cx.editor.close(view!(cx.editor).id);
 
     Ok(())
@@ -70,14 +75,16 @@ fn open(cx: &mut compositor::Context, args: &[Cow<str>], event: PromptEvent) ->
 }
 
 fn buffer_close_by_ids_impl(
-    editor: &mut Editor,
+    cx: &mut compositor::Context,
     doc_ids: &[DocumentId],
     force: bool,
 ) -> anyhow::Result<()> {
+    cx.block_try_flush_writes()?;
+
     let (modified_ids, modified_names): (Vec<_>, Vec<_>) = doc_ids
         .iter()
         .filter_map(|&doc_id| {
-            if let Err(CloseError::BufferModified(name)) = editor.close_document(doc_id, force) {
+            if let Err(CloseError::BufferModified(name)) = cx.editor.close_document(doc_id, force) {
                 Some((doc_id, name))
             } else {
                 None
@@ -86,11 +93,11 @@ fn buffer_close_by_ids_impl(
         .unzip();
 
     if let Some(first) = modified_ids.first() {
-        let current = doc!(editor);
+        let current = doc!(cx.editor);
         // If the current document is unmodified, and there are modified
         // documents, switch focus to the first modified doc.
         if !modified_ids.contains(&current.id()) {
-            editor.switch(*first, Action::Replace);
+            cx.editor.switch(*first, Action::Replace);
         }
         bail!(
             "{} unsaved buffer(s) remaining: {:?}",
@@ -149,7 +156,7 @@ fn buffer_close(
     }
 
     let document_ids = buffer_gather_paths_impl(cx.editor, args);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, false)
+    buffer_close_by_ids_impl(cx, &document_ids, false)
 }
 
 fn force_buffer_close(
@@ -162,7 +169,7 @@ fn force_buffer_close(
     }
 
     let document_ids = buffer_gather_paths_impl(cx.editor, args);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, true)
+    buffer_close_by_ids_impl(cx, &document_ids, true)
 }
 
 fn buffer_gather_others_impl(editor: &mut Editor) -> Vec<DocumentId> {
@@ -184,7 +191,7 @@ fn buffer_close_others(
     }
 
     let document_ids = buffer_gather_others_impl(cx.editor);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, false)
+    buffer_close_by_ids_impl(cx, &document_ids, false)
 }
 
 fn force_buffer_close_others(
@@ -197,7 +204,7 @@ fn force_buffer_close_others(
     }
 
     let document_ids = buffer_gather_others_impl(cx.editor);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, true)
+    buffer_close_by_ids_impl(cx, &document_ids, true)
 }
 
 fn buffer_gather_all_impl(editor: &mut Editor) -> Vec<DocumentId> {
@@ -214,7 +221,7 @@ fn buffer_close_all(
     }
 
     let document_ids = buffer_gather_all_impl(cx.editor);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, false)
+    buffer_close_by_ids_impl(cx, &document_ids, false)
 }
 
 fn force_buffer_close_all(
@@ -227,7 +234,7 @@ fn force_buffer_close_all(
     }
 
     let document_ids = buffer_gather_all_impl(cx.editor);
-    buffer_close_by_ids_impl(cx.editor, &document_ids, true)
+    buffer_close_by_ids_impl(cx, &document_ids, true)
 }
 
 fn buffer_next(
@@ -261,39 +268,29 @@ fn write_impl(
     path: Option<&Cow<str>>,
     force: bool,
 ) -> anyhow::Result<()> {
-    let auto_format = cx.editor.config().auto_format;
+    let editor_auto_fmt = cx.editor.config().auto_format;
     let jobs = &mut cx.jobs;
     let doc = doc_mut!(cx.editor);
+    let path = path.map(AsRef::as_ref);
 
-    if let Some(ref path) = path {
-        doc.set_path(Some(path.as_ref().as_ref()))
-            .context("invalid filepath")?;
-    }
-    if doc.path().is_none() {
-        bail!("cannot write a buffer without a filename");
-    }
-    let fmt = if auto_format {
+    let fmt = if editor_auto_fmt {
         doc.auto_format().map(|fmt| {
-            let shared = fmt.shared();
             let callback = make_format_callback(
                 doc.id(),
                 doc.version(),
-                Modified::SetUnmodified,
-                shared.clone(),
+                fmt,
+                Some((path.map(Into::into), force)),
             );
-            jobs.callback(callback);
-            shared
+
+            jobs.add(Job::with_callback(callback).wait_before_exiting());
         })
     } else {
         None
     };
-    let future = doc.format_and_save(fmt, force);
-    cx.jobs.add(Job::new(future).wait_before_exiting());
 
-    if path.is_some() {
+    if fmt.is_none() {
         let id = doc.id();
-        doc.detect_language(cx.editor.syn_loader.clone());
-        let _ = cx.editor.refresh_language_server(id);
+        cx.editor.save(id, path, force)?;
     }
 
     Ok(())
@@ -348,8 +345,7 @@ fn format(
 
     let doc = doc!(cx.editor);
     if let Some(format) = doc.format() {
-        let callback =
-            make_format_callback(doc.id(), doc.version(), Modified::LeaveModified, format);
+        let callback = make_format_callback(doc.id(), doc.version(), format, None);
         cx.jobs.callback(callback);
     }
 
@@ -520,7 +516,7 @@ fn write_quit(
     }
 
     write_impl(cx, args.first(), false)?;
-    helix_lsp::block_on(cx.jobs.finish())?;
+    cx.block_try_flush_writes()?;
     quit(cx, &[], event)
 }
 
@@ -534,6 +530,7 @@ fn force_write_quit(
     }
 
     write_impl(cx, args.first(), true)?;
+    cx.block_try_flush_writes()?;
     force_quit(cx, &[], event)
 }
 
@@ -573,40 +570,50 @@ fn write_all_impl(
         return Ok(());
     }
 
-    let mut errors = String::new();
+    let mut errors: Vec<&'static str> = Vec::new();
     let auto_format = cx.editor.config().auto_format;
     let jobs = &mut cx.jobs;
+
     // save all documents
-    for doc in &mut cx.editor.documents.values_mut() {
-        if doc.path().is_none() {
-            errors.push_str("cannot write a buffer without a filename\n");
-            continue;
-        }
+    let saves: Vec<_> = cx
+        .editor
+        .documents
+        .values()
+        .filter_map(|doc| {
+            if doc.path().is_none() {
+                errors.push("cannot write a buffer without a filename\n");
+                return None;
+            }
 
-        if !doc.is_modified() {
-            continue;
-        }
+            if !doc.is_modified() {
+                return None;
+            }
 
-        let fmt = if auto_format {
-            doc.auto_format().map(|fmt| {
-                let shared = fmt.shared();
-                let callback = make_format_callback(
-                    doc.id(),
-                    doc.version(),
-                    Modified::SetUnmodified,
-                    shared.clone(),
-                );
-                jobs.callback(callback);
-                shared
-            })
-        } else {
+            let fmt = if auto_format {
+                doc.auto_format().map(|fmt| {
+                    let callback =
+                        make_format_callback(doc.id(), doc.version(), fmt, Some((None, force)));
+                    jobs.add(Job::with_callback(callback).wait_before_exiting());
+                })
+            } else {
+                None
+            };
+
+            if fmt.is_none() {
+                return Some(doc.id());
+            }
             None
-        };
-        let future = doc.format_and_save(fmt, force);
-        jobs.add(Job::new(future).wait_before_exiting());
+        })
+        .collect();
+
+    // manually call save for the rest of docs that don't have a formatter
+    for id in saves {
+        cx.editor.save::<PathBuf>(id, None, force)?;
     }
 
     if quit {
+        cx.block_try_flush_writes()?;
+
         if !force {
             buffers_remaining_impl(cx.editor)?;
         }
@@ -618,7 +625,11 @@ fn write_all_impl(
         }
     }
 
-    bail!(errors)
+    if !errors.is_empty() && !force {
+        bail!("{:?}", errors);
+    }
+
+    Ok(())
 }
 
 fn write_all(
@@ -680,6 +691,7 @@ fn quit_all(
         return Ok(());
     }
 
+    cx.block_try_flush_writes()?;
     quit_all_impl(cx.editor, false)
 }
 
@@ -708,8 +720,9 @@ fn cquit(
         .first()
         .and_then(|code| code.parse::<i32>().ok())
         .unwrap_or(1);
-    cx.editor.exit_code = exit_code;
 
+    cx.editor.exit_code = exit_code;
+    cx.block_try_flush_writes()?;
     quit_all_impl(cx.editor, false)
 }
 
@@ -1064,12 +1077,13 @@ fn tree_sitter_scopes(
     let contents = format!("```json\n{:?}\n````", scopes);
 
     let callback = async move {
-        let call: job::Callback =
-            Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
+        let call: job::Callback = Callback::EditorCompositor(Box::new(
+            move |editor: &mut Editor, compositor: &mut Compositor| {
                 let contents = ui::Markdown::new(contents, editor.syn_loader.clone());
                 let popup = Popup::new("hover", contents).auto_close(true);
                 compositor.replace_or_push("hover", popup);
-            });
+            },
+        ));
         Ok(call)
     };
 
@@ -1492,12 +1506,13 @@ fn tree_sitter_subtree(
             contents.push_str("\n```");
 
             let callback = async move {
-                let call: job::Callback =
-                    Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
+                let call: job::Callback = Callback::EditorCompositor(Box::new(
+                    move |editor: &mut Editor, compositor: &mut Compositor| {
                         let contents = ui::Markdown::new(contents, editor.syn_loader.clone());
                         let popup = Popup::new("hover", contents).auto_close(true);
                         compositor.replace_or_push("hover", popup);
-                    });
+                    },
+                ));
                 Ok(call)
             };
 
@@ -1605,8 +1620,8 @@ fn run_shell_command(
 
     if !output.is_empty() {
         let callback = async move {
-            let call: job::Callback =
-                Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
+            let call: job::Callback = Callback::EditorCompositor(Box::new(
+                move |editor: &mut Editor, compositor: &mut Compositor| {
                     let contents = ui::Markdown::new(
                         format!("```sh\n{}\n```", output),
                         editor.syn_loader.clone(),
@@ -1615,7 +1630,8 @@ fn run_shell_command(
                         helix_core::Position::new(editor.cursor().0.unwrap_or_default().row, 2),
                     ));
                     compositor.replace_or_push("shell", popup);
-                });
+                },
+            ));
             Ok(call)
         };
 
diff --git a/helix-term/src/compositor.rs b/helix-term/src/compositor.rs
index c0898dae..971dc52d 100644
--- a/helix-term/src/compositor.rs
+++ b/helix-term/src/compositor.rs
@@ -27,6 +27,16 @@ pub struct Context<'a> {
     pub jobs: &'a mut Jobs,
 }
 
+impl<'a> Context<'a> {
+    /// Waits on all pending jobs, and then tries to flush all pending write
+    /// operations for all documents.
+    pub fn block_try_flush_writes(&mut self) -> anyhow::Result<()> {
+        tokio::task::block_in_place(|| helix_lsp::block_on(self.jobs.finish(self.editor, None)))?;
+        tokio::task::block_in_place(|| helix_lsp::block_on(self.editor.flush_writes()))?;
+        Ok(())
+    }
+}
+
 pub trait Component: Any + AnyComponent {
     /// Process input events, return true if handled.
     fn handle_event(&mut self, _event: &Event, _ctx: &mut Context) -> EventResult {
diff --git a/helix-term/src/job.rs b/helix-term/src/job.rs
index e5147992..2888b6eb 100644
--- a/helix-term/src/job.rs
+++ b/helix-term/src/job.rs
@@ -5,7 +5,11 @@ use crate::compositor::Compositor;
 use futures_util::future::{BoxFuture, Future, FutureExt};
 use futures_util::stream::{FuturesUnordered, StreamExt};
 
-pub type Callback = Box<dyn FnOnce(&mut Editor, &mut Compositor) + Send>;
+pub enum Callback {
+    EditorCompositor(Box<dyn FnOnce(&mut Editor, &mut Compositor) + Send>),
+    Editor(Box<dyn FnOnce(&mut Editor) + Send>),
+}
+
 pub type JobFuture = BoxFuture<'static, anyhow::Result<Option<Callback>>>;
 
 pub struct Job {
@@ -68,9 +72,10 @@ impl Jobs {
     ) {
         match call {
             Ok(None) => {}
-            Ok(Some(call)) => {
-                call(editor, compositor);
-            }
+            Ok(Some(call)) => match call {
+                Callback::EditorCompositor(call) => call(editor, compositor),
+                Callback::Editor(call) => call(editor),
+            },
             Err(e) => {
                 editor.set_error(format!("Async job failed: {}", e));
             }
@@ -93,13 +98,32 @@ impl Jobs {
     }
 
     /// Blocks until all the jobs that need to be waited on are done.
-    pub async fn finish(&mut self) -> anyhow::Result<()> {
+    pub async fn finish(
+        &mut self,
+        editor: &mut Editor,
+        mut compositor: Option<&mut Compositor>,
+    ) -> anyhow::Result<()> {
         log::debug!("waiting on jobs...");
         let mut wait_futures = std::mem::take(&mut self.wait_futures);
+
         while let (Some(job), tail) = wait_futures.into_future().await {
             match job {
-                Ok(_) => {
+                Ok(callback) => {
                     wait_futures = tail;
+
+                    if let Some(callback) = callback {
+                        // clippy doesn't realize this is an error without the derefs
+                        #[allow(clippy::needless_option_as_deref)]
+                        match callback {
+                            Callback::EditorCompositor(call) if compositor.is_some() => {
+                                call(editor, compositor.as_deref_mut().unwrap())
+                            }
+                            Callback::Editor(call) => call(editor),
+
+                            // skip callbacks for which we don't have the necessary references
+                            _ => (),
+                        }
+                    }
                 }
                 Err(e) => {
                     self.wait_futures = tail;
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index 726bf9e3..96b695c6 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -139,8 +139,18 @@ FLAGS:
         Err(err) => return Err(Error::new(err)),
     };
 
+    let syn_loader_conf = helix_core::config::user_syntax_loader().unwrap_or_else(|err| {
+        eprintln!("Bad language config: {}", err);
+        eprintln!("Press <ENTER> to continue with default language config");
+        use std::io::Read;
+        // This waits for an enter press.
+        let _ = std::io::stdin().read(&mut []);
+        helix_core::config::default_syntax_loader()
+    });
+
     // TODO: use the thread local executor to spawn the application task separately from the work pool
-    let mut app = Application::new(args, config).context("unable to create new application")?;
+    let mut app = Application::new(args, config, syn_loader_conf)
+        .context("unable to create new application")?;
 
     let exit_code = app.run(&mut EventStream::new()).await?;
 
diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index 3cd2130a..73dfd52c 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -1,7 +1,8 @@
 use crate::{
     commands,
     compositor::{Component, Context, Event, EventResult},
-    job, key,
+    job::{self, Callback},
+    key,
     keymap::{KeymapResult, Keymaps},
     ui::{Completion, ProgressSpinners},
 };
@@ -944,9 +945,10 @@ impl EditorView {
 
                     // TODO: Use an on_mode_change hook to remove signature help
                     cxt.jobs.callback(async {
-                        let call: job::Callback = Box::new(|_editor, compositor| {
-                            compositor.remove(SignatureHelp::ID);
-                        });
+                        let call: job::Callback =
+                            Callback::EditorCompositor(Box::new(|_editor, compositor| {
+                                compositor.remove(SignatureHelp::ID);
+                            }));
                         Ok(call)
                     });
                 }
diff --git a/helix-term/src/ui/mod.rs b/helix-term/src/ui/mod.rs
index 6ac4dbb7..f99dea0b 100644
--- a/helix-term/src/ui/mod.rs
+++ b/helix-term/src/ui/mod.rs
@@ -14,7 +14,7 @@ mod statusline;
 mod text;
 
 use crate::compositor::{Component, Compositor};
-use crate::job;
+use crate::job::{self, Callback};
 pub use completion::Completion;
 pub use editor::EditorView;
 pub use markdown::Markdown;
@@ -121,7 +121,7 @@ pub fn regex_prompt(
 
                             if event == PromptEvent::Validate {
                                 let callback = async move {
-                                    let call: job::Callback = Box::new(
+                                    let call: job::Callback = Callback::EditorCompositor(Box::new(
                                         move |_editor: &mut Editor, compositor: &mut Compositor| {
                                             let contents = Text::new(format!("{}", err));
                                             let size = compositor.size();
@@ -135,7 +135,7 @@ pub fn regex_prompt(
 
                                             compositor.replace_or_push("invalid-regex", popup);
                                         },
-                                    );
+                                    ));
                                     Ok(call)
                                 };
 
diff --git a/helix-term/tests/integration.rs b/helix-term/tests/integration.rs
index 8969e976..e3754c43 100644
--- a/helix-term/tests/integration.rs
+++ b/helix-term/tests/integration.rs
@@ -22,5 +22,6 @@ mod test {
     mod commands;
     mod movement;
     mod prompt;
+    mod splits;
     mod write;
 }
diff --git a/helix-term/tests/test/auto_indent.rs b/helix-term/tests/test/auto_indent.rs
index 2f638893..5c093a5d 100644
--- a/helix-term/tests/test/auto_indent.rs
+++ b/helix-term/tests/test/auto_indent.rs
@@ -8,6 +8,7 @@ async fn auto_indent_c() -> anyhow::Result<()> {
             ..Default::default()
         },
         Config::default(),
+        helpers::test_syntax_conf(None),
         // switches to append mode?
         (
             helpers::platform_line("void foo() {#[|}]#").as_ref(),
diff --git a/helix-term/tests/test/auto_pairs.rs b/helix-term/tests/test/auto_pairs.rs
index ec47a5b4..caf80bd4 100644
--- a/helix-term/tests/test/auto_pairs.rs
+++ b/helix-term/tests/test/auto_pairs.rs
@@ -13,6 +13,7 @@ async fn auto_pairs_basic() -> anyhow::Result<()> {
             },
             ..Default::default()
         },
+        helpers::test_syntax_conf(None),
         ("#[\n|]#", "i(<esc>", "(#[|\n]#"),
     )
     .await?;
diff --git a/helix-term/tests/test/commands.rs b/helix-term/tests/test/commands.rs
index f7ce9af0..5238cc69 100644
--- a/helix-term/tests/test/commands.rs
+++ b/helix-term/tests/test/commands.rs
@@ -1,21 +1,25 @@
-use std::{
-    io::{Read, Write},
-    ops::RangeInclusive,
-};
+use std::ops::RangeInclusive;
 
 use helix_core::diagnostic::Severity;
-use helix_term::application::Application;
 
 use super::*;
 
-#[tokio::test]
+#[tokio::test(flavor = "multi_thread")]
 async fn test_write_quit_fail() -> anyhow::Result<()> {
     let file = helpers::new_readonly_tempfile()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
 
     test_key_sequence(
-        &mut helpers::app_with_file(file.path())?,
+        &mut app,
         Some("ihello<esc>:wq<ret>"),
         Some(&|app| {
+            let mut docs: Vec<_> = app.editor.documents().collect();
+            assert_eq!(1, docs.len());
+
+            let doc = docs.pop().unwrap();
+            assert_eq!(Some(file.path()), doc.path().map(PathBuf::as_path));
             assert_eq!(&Severity::Error, app.editor.get_status().unwrap().1);
         }),
         false,
@@ -25,11 +29,10 @@ async fn test_write_quit_fail() -> anyhow::Result<()> {
     Ok(())
 }
 
-#[tokio::test]
-#[ignore]
+#[tokio::test(flavor = "multi_thread")]
 async fn test_buffer_close_concurrent() -> anyhow::Result<()> {
     test_key_sequences(
-        &mut Application::new(Args::default(), Config::default())?,
+        &mut helpers::AppBuilder::new().build()?,
         vec![
             (
                 None,
@@ -69,8 +72,12 @@ async fn test_buffer_close_concurrent() -> anyhow::Result<()> {
 
     command.push_str(":buffer<minus>close<ret>");
 
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
+
     test_key_sequence(
-        &mut helpers::app_with_file(file.path())?,
+        &mut app,
         Some(&command),
         Some(&|app| {
             assert!(!app.editor.is_err(), "error: {:?}", app.editor.get_status());
@@ -82,12 +89,7 @@ async fn test_buffer_close_concurrent() -> anyhow::Result<()> {
     )
     .await?;
 
-    file.as_file_mut().flush()?;
-    file.as_file_mut().sync_all()?;
-
-    let mut file_content = String::new();
-    file.as_file_mut().read_to_string(&mut file_content)?;
-    assert_eq!(RANGE.end().to_string(), file_content);
+    helpers::assert_file_has_content(file.as_file_mut(), &RANGE.end().to_string())?;
 
     Ok(())
 }
diff --git a/helix-term/tests/test/helpers.rs b/helix-term/tests/test/helpers.rs
index 8f2501e6..5adc3354 100644
--- a/helix-term/tests/test/helpers.rs
+++ b/helix-term/tests/test/helpers.rs
@@ -1,10 +1,15 @@
-use std::{io::Write, path::PathBuf, time::Duration};
+use std::{
+    fs::File,
+    io::{Read, Write},
+    path::PathBuf,
+    time::Duration,
+};
 
 use anyhow::bail;
 use crossterm::event::{Event, KeyEvent};
-use helix_core::{test, Selection, Transaction};
+use helix_core::{diagnostic::Severity, test, Selection, Transaction};
 use helix_term::{application::Application, args::Args, config::Config};
-use helix_view::{doc, input::parse_macro};
+use helix_view::{doc, input::parse_macro, Editor};
 use tempfile::NamedTempFile;
 use tokio_stream::wrappers::UnboundedReceiverStream;
 
@@ -56,7 +61,9 @@ pub async fn test_key_sequences(
     for (i, (in_keys, test_fn)) in inputs.into_iter().enumerate() {
         if let Some(in_keys) = in_keys {
             for key_event in parse_macro(in_keys)?.into_iter() {
-                tx.send(Ok(Event::Key(KeyEvent::from(key_event))))?;
+                let key = Event::Key(KeyEvent::from(key_event));
+                log::trace!("sending key: {:?}", key);
+                tx.send(Ok(key))?;
             }
         }
 
@@ -70,7 +77,7 @@ pub async fn test_key_sequences(
         // verify if it exited on the last iteration if it should have and
         // the inverse
         if i == num_inputs - 1 && app_exited != should_exit {
-            bail!("expected app to exit: {} != {}", app_exited, should_exit);
+            bail!("expected app to exit: {} != {}", should_exit, app_exited);
         }
 
         if let Some(test) = test_fn {
@@ -87,7 +94,17 @@ pub async fn test_key_sequences(
         tokio::time::timeout(TIMEOUT, event_loop).await?;
     }
 
-    app.close().await?;
+    let errs = app.close().await;
+
+    if !errs.is_empty() {
+        log::error!("Errors closing app");
+
+        for err in errs {
+            log::error!("{}", err);
+        }
+
+        bail!("Error closing app");
+    }
 
     Ok(())
 }
@@ -101,7 +118,7 @@ pub async fn test_key_sequence_with_input_text<T: Into<TestCase>>(
     let test_case = test_case.into();
     let mut app = match app {
         Some(app) => app,
-        None => Application::new(Args::default(), Config::default())?,
+        None => Application::new(Args::default(), Config::default(), test_syntax_conf(None))?,
     };
 
     let (view, doc) = helix_view::current!(app.editor);
@@ -125,16 +142,30 @@ pub async fn test_key_sequence_with_input_text<T: Into<TestCase>>(
     .await
 }
 
+/// Generates language configs that merge in overrides, like a user language
+/// config. The argument string must be a raw TOML document.
+pub fn test_syntax_conf(overrides: Option<String>) -> helix_core::syntax::Configuration {
+    let mut lang = helix_loader::config::default_lang_config();
+
+    if let Some(overrides) = overrides {
+        let override_toml = toml::from_str(&overrides).unwrap();
+        lang = helix_loader::merge_toml_values(lang, override_toml, 3);
+    }
+
+    lang.try_into().unwrap()
+}
+
 /// Use this for very simple test cases where there is one input
 /// document, selection, and sequence of key presses, and you just
 /// want to verify the resulting document and selection.
 pub async fn test_with_config<T: Into<TestCase>>(
     args: Args,
     config: Config,
+    syn_conf: helix_core::syntax::Configuration,
     test_case: T,
 ) -> anyhow::Result<()> {
     let test_case = test_case.into();
-    let app = Application::new(args, config)?;
+    let app = Application::new(args, config, syn_conf)?;
 
     test_key_sequence_with_input_text(
         Some(app),
@@ -155,7 +186,13 @@ pub async fn test_with_config<T: Into<TestCase>>(
 }
 
 pub async fn test<T: Into<TestCase>>(test_case: T) -> anyhow::Result<()> {
-    test_with_config(Args::default(), Config::default(), test_case).await
+    test_with_config(
+        Args::default(),
+        Config::default(),
+        test_syntax_conf(None),
+        test_case,
+    )
+    .await
 }
 
 pub fn temp_file_with_contents<S: AsRef<str>>(
@@ -200,14 +237,75 @@ pub fn new_readonly_tempfile() -> anyhow::Result<NamedTempFile> {
     Ok(file)
 }
 
-/// Creates a new Application with default config that opens the given file
-/// path
-pub fn app_with_file<P: Into<PathBuf>>(path: P) -> anyhow::Result<Application> {
-    Application::new(
-        Args {
-            files: vec![(path.into(), helix_core::Position::default())],
-            ..Default::default()
-        },
-        Config::default(),
-    )
+#[derive(Default)]
+pub struct AppBuilder {
+    args: Args,
+    config: Config,
+    syn_conf: helix_core::syntax::Configuration,
+    input: Option<(String, Selection)>,
+}
+
+impl AppBuilder {
+    pub fn new() -> Self {
+        AppBuilder::default()
+    }
+
+    pub fn with_file<P: Into<PathBuf>>(
+        mut self,
+        path: P,
+        pos: Option<helix_core::Position>,
+    ) -> Self {
+        self.args.files.push((path.into(), pos.unwrap_or_default()));
+        self
+    }
+
+    pub fn with_config(mut self, config: Config) -> Self {
+        self.config = config;
+        self
+    }
+
+    pub fn with_input_text<S: Into<String>>(mut self, input_text: S) -> Self {
+        self.input = Some(test::print(&input_text.into()));
+        self
+    }
+
+    pub fn with_lang_config(mut self, syn_conf: helix_core::syntax::Configuration) -> Self {
+        self.syn_conf = syn_conf;
+        self
+    }
+
+    pub fn build(self) -> anyhow::Result<Application> {
+        let mut app = Application::new(self.args, self.config, self.syn_conf)?;
+
+        if let Some((text, selection)) = self.input {
+            let (view, doc) = helix_view::current!(app.editor);
+            let sel = doc.selection(view.id).clone();
+            let trans = Transaction::change_by_selection(doc.text(), &sel, |_| {
+                (0, doc.text().len_chars(), Some((text.clone()).into()))
+            })
+            .with_selection(selection);
+
+            // replace the initial text with the input text
+            doc.apply(&trans, view.id);
+        }
+
+        Ok(app)
+    }
+}
+
+pub fn assert_file_has_content(file: &mut File, content: &str) -> anyhow::Result<()> {
+    file.flush()?;
+    file.sync_all()?;
+
+    let mut file_content = String::new();
+    file.read_to_string(&mut file_content)?;
+    assert_eq!(content, file_content);
+
+    Ok(())
+}
+
+pub fn assert_status_not_error(editor: &Editor) {
+    if let Some((_, sev)) = editor.get_status() {
+        assert_ne!(&Severity::Error, sev);
+    }
 }
diff --git a/helix-term/tests/test/movement.rs b/helix-term/tests/test/movement.rs
index 45aae39e..81c66e53 100644
--- a/helix-term/tests/test/movement.rs
+++ b/helix-term/tests/test/movement.rs
@@ -70,7 +70,9 @@ async fn insert_to_normal_mode_cursor_position() -> anyhow::Result<()> {
 async fn cursor_position_newly_opened_file() -> anyhow::Result<()> {
     let test = |content: &str, expected_sel: Selection| -> anyhow::Result<()> {
         let file = helpers::temp_file_with_contents(content)?;
-        let mut app = helpers::app_with_file(file.path())?;
+        let mut app = helpers::AppBuilder::new()
+            .with_file(file.path(), None)
+            .build()?;
 
         let (view, doc) = helix_view::current!(app.editor);
         let sel = doc.selection(view.id).clone();
@@ -115,6 +117,7 @@ async fn select_mode_tree_sitter_next_function_is_union_of_objects() -> anyhow::
             ..Default::default()
         },
         Config::default(),
+        helpers::test_syntax_conf(None),
         (
             helpers::platform_line(indoc! {"\
                 #[/|]#// Increments
@@ -146,6 +149,7 @@ async fn select_mode_tree_sitter_prev_function_unselects_object() -> anyhow::Res
             ..Default::default()
         },
         Config::default(),
+        helpers::test_syntax_conf(None),
         (
             helpers::platform_line(indoc! {"\
                 /// Increments
@@ -178,6 +182,7 @@ async fn select_mode_tree_sitter_prev_function_goes_backwards_to_object() -> any
             ..Default::default()
         },
         Config::default(),
+        helpers::test_syntax_conf(None),
         (
             helpers::platform_line(indoc! {"\
                 /// Increments
@@ -208,6 +213,7 @@ async fn select_mode_tree_sitter_prev_function_goes_backwards_to_object() -> any
             ..Default::default()
         },
         Config::default(),
+        helpers::test_syntax_conf(None),
         (
             helpers::platform_line(indoc! {"\
                 /// Increments
diff --git a/helix-term/tests/test/prompt.rs b/helix-term/tests/test/prompt.rs
index 2ab9604c..62ec03f1 100644
--- a/helix-term/tests/test/prompt.rs
+++ b/helix-term/tests/test/prompt.rs
@@ -1,11 +1,9 @@
 use super::*;
 
-use helix_term::application::Application;
-
 #[tokio::test]
 async fn test_history_completion() -> anyhow::Result<()> {
     test_key_sequence(
-        &mut Application::new(Args::default(), Config::default())?,
+        &mut AppBuilder::new().build()?,
         Some(":asdf<ret>:theme d<C-n><tab>"),
         Some(&|app| {
             assert!(!app.editor.is_err());
diff --git a/helix-term/tests/test/splits.rs b/helix-term/tests/test/splits.rs
new file mode 100644
index 00000000..5807413a
--- /dev/null
+++ b/helix-term/tests/test/splits.rs
@@ -0,0 +1,129 @@
+use super::*;
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_split_write_quit_all() -> anyhow::Result<()> {
+    let mut file1 = tempfile::NamedTempFile::new()?;
+    let mut file2 = tempfile::NamedTempFile::new()?;
+    let mut file3 = tempfile::NamedTempFile::new()?;
+
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file1.path(), None)
+        .build()?;
+
+    test_key_sequences(
+        &mut app,
+        vec![
+            (
+                Some(&format!(
+                    "ihello1<esc>:sp<ret>:o {}<ret>ihello2<esc>:sp<ret>:o {}<ret>ihello3<esc>",
+                    file2.path().to_string_lossy(),
+                    file3.path().to_string_lossy()
+                )),
+                Some(&|app| {
+                    let docs: Vec<_> = app.editor.documents().collect();
+                    assert_eq!(3, docs.len());
+
+                    let doc1 = docs
+                        .iter()
+                        .find(|doc| doc.path().unwrap() == file1.path())
+                        .unwrap();
+
+                    assert_eq!("hello1", doc1.text().to_string());
+
+                    let doc2 = docs
+                        .iter()
+                        .find(|doc| doc.path().unwrap() == file2.path())
+                        .unwrap();
+
+                    assert_eq!("hello2", doc2.text().to_string());
+
+                    let doc3 = docs
+                        .iter()
+                        .find(|doc| doc.path().unwrap() == file3.path())
+                        .unwrap();
+
+                    assert_eq!("hello3", doc3.text().to_string());
+
+                    helpers::assert_status_not_error(&app.editor);
+                    assert_eq!(3, app.editor.tree.views().count());
+                }),
+            ),
+            (
+                Some(":wqa<ret>"),
+                Some(&|app| {
+                    helpers::assert_status_not_error(&app.editor);
+                    assert_eq!(0, app.editor.tree.views().count());
+                }),
+            ),
+        ],
+        true,
+    )
+    .await?;
+
+    helpers::assert_file_has_content(file1.as_file_mut(), "hello1")?;
+    helpers::assert_file_has_content(file2.as_file_mut(), "hello2")?;
+    helpers::assert_file_has_content(file3.as_file_mut(), "hello3")?;
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_split_write_quit_same_file() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
+
+    test_key_sequences(
+        &mut app,
+        vec![
+            (
+                Some("O<esc>ihello<esc>:sp<ret>ogoodbye<esc>"),
+                Some(&|app| {
+                    assert_eq!(2, app.editor.tree.views().count());
+                    helpers::assert_status_not_error(&app.editor);
+
+                    let mut docs: Vec<_> = app.editor.documents().collect();
+                    assert_eq!(1, docs.len());
+
+                    let doc = docs.pop().unwrap();
+
+                    assert_eq!(
+                        helpers::platform_line("hello\ngoodbye"),
+                        doc.text().to_string()
+                    );
+
+                    assert!(doc.is_modified());
+                }),
+            ),
+            (
+                Some(":wq<ret>"),
+                Some(&|app| {
+                    helpers::assert_status_not_error(&app.editor);
+                    assert_eq!(1, app.editor.tree.views().count());
+
+                    let mut docs: Vec<_> = app.editor.documents().collect();
+                    assert_eq!(1, docs.len());
+
+                    let doc = docs.pop().unwrap();
+
+                    assert_eq!(
+                        helpers::platform_line("hello\ngoodbye"),
+                        doc.text().to_string()
+                    );
+
+                    assert!(!doc.is_modified());
+                }),
+            ),
+        ],
+        false,
+    )
+    .await?;
+
+    helpers::assert_file_has_content(
+        file.as_file_mut(),
+        &helpers::platform_line("hello\ngoodbye"),
+    )?;
+
+    Ok(())
+}
diff --git a/helix-term/tests/test/write.rs b/helix-term/tests/test/write.rs
index 8869d881..6aa51a31 100644
--- a/helix-term/tests/test/write.rs
+++ b/helix-term/tests/test/write.rs
@@ -4,7 +4,6 @@ use std::{
 };
 
 use helix_core::diagnostic::Severity;
-use helix_term::application::Application;
 use helix_view::doc;
 
 use super::*;
@@ -12,9 +11,12 @@ use super::*;
 #[tokio::test]
 async fn test_write() -> anyhow::Result<()> {
     let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
 
     test_key_sequence(
-        &mut helpers::app_with_file(file.path())?,
+        &mut app,
         Some("ithe gostak distims the doshes<ret><esc>:w<ret>"),
         None,
         false,
@@ -35,12 +37,15 @@ async fn test_write() -> anyhow::Result<()> {
     Ok(())
 }
 
-#[tokio::test]
+#[tokio::test(flavor = "multi_thread")]
 async fn test_write_quit() -> anyhow::Result<()> {
     let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
 
     test_key_sequence(
-        &mut helpers::app_with_file(file.path())?,
+        &mut app,
         Some("ithe gostak distims the doshes<ret><esc>:wq<ret>"),
         None,
         true,
@@ -61,25 +66,21 @@ async fn test_write_quit() -> anyhow::Result<()> {
     Ok(())
 }
 
-#[tokio::test]
-#[ignore]
+#[tokio::test(flavor = "multi_thread")]
 async fn test_write_concurrent() -> anyhow::Result<()> {
     let mut file = tempfile::NamedTempFile::new()?;
     let mut command = String::new();
     const RANGE: RangeInclusive<i32> = 1..=5000;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
 
     for i in RANGE {
         let cmd = format!("%c{}<esc>:w<ret>", i);
         command.push_str(&cmd);
     }
 
-    test_key_sequence(
-        &mut helpers::app_with_file(file.path())?,
-        Some(&command),
-        None,
-        false,
-    )
-    .await?;
+    test_key_sequence(&mut app, Some(&command), None, false).await?;
 
     file.as_file_mut().flush()?;
     file.as_file_mut().sync_all()?;
@@ -92,12 +93,14 @@ async fn test_write_concurrent() -> anyhow::Result<()> {
 }
 
 #[tokio::test]
-#[ignore]
 async fn test_write_fail_mod_flag() -> anyhow::Result<()> {
     let file = helpers::new_readonly_tempfile()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
 
     test_key_sequences(
-        &mut helpers::app_with_file(file.path())?,
+        &mut app,
         vec![
             (
                 None,
@@ -131,12 +134,127 @@ async fn test_write_fail_mod_flag() -> anyhow::Result<()> {
 }
 
 #[tokio::test]
-#[ignore]
+async fn test_write_scratch_to_new_path() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+
+    test_key_sequence(
+        &mut AppBuilder::new().build()?,
+        Some(format!("ihello<esc>:w {}<ret>", file.path().to_string_lossy()).as_ref()),
+        Some(&|app| {
+            assert!(!app.editor.is_err());
+
+            let mut docs: Vec<_> = app.editor.documents().collect();
+            assert_eq!(1, docs.len());
+
+            let doc = docs.pop().unwrap();
+            assert_eq!(Some(&file.path().to_path_buf()), doc.path());
+        }),
+        false,
+    )
+    .await?;
+
+    helpers::assert_file_has_content(file.as_file_mut(), &helpers::platform_line("hello"))?;
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_write_scratch_no_path_fails() -> anyhow::Result<()> {
+    helpers::test_key_sequence_with_input_text(
+        None,
+        ("#[\n|]#", "ihello<esc>:w<ret>", "hello#[\n|]#"),
+        &|app| {
+            assert!(app.editor.is_err());
+
+            let mut docs: Vec<_> = app.editor.documents().collect();
+            assert_eq!(1, docs.len());
+
+            let doc = docs.pop().unwrap();
+            assert_eq!(None, doc.path());
+        },
+        false,
+    )
+    .await?;
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_write_auto_format_fails_still_writes() -> anyhow::Result<()> {
+    let mut file = tempfile::Builder::new().suffix(".rs").tempfile()?;
+
+    let lang_conf = indoc! {r#"
+            [[language]]
+            name = "rust"
+            formatter = { command = "bash", args = [ "-c", "exit 1" ] }
+        "#};
+
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .with_input_text("#[l|]#et foo = 0;\n")
+        .with_lang_config(helpers::test_syntax_conf(Some(lang_conf.into())))
+        .build()?;
+
+    test_key_sequences(&mut app, vec![(Some(":w<ret>"), None)], false).await?;
+
+    // file still saves
+    helpers::assert_file_has_content(file.as_file_mut(), "let foo = 0;\n")?;
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_write_new_path() -> anyhow::Result<()> {
+    let mut file1 = tempfile::NamedTempFile::new().unwrap();
+    let mut file2 = tempfile::NamedTempFile::new().unwrap();
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file1.path(), None)
+        .build()?;
+
+    test_key_sequences(
+        &mut app,
+        vec![
+            (
+                Some("ii can eat glass, it will not hurt me<ret><esc>:w<ret>"),
+                Some(&|app| {
+                    let doc = doc!(app.editor);
+                    assert!(!app.editor.is_err());
+                    assert_eq!(file1.path(), doc.path().unwrap());
+                }),
+            ),
+            (
+                Some(&format!(":w {}<ret>", file2.path().to_string_lossy())),
+                Some(&|app| {
+                    let doc = doc!(app.editor);
+                    assert!(!app.editor.is_err());
+                    assert_eq!(file2.path(), doc.path().unwrap());
+                    assert!(app.editor.document_by_path(file1.path()).is_none());
+                }),
+            ),
+        ],
+        false,
+    )
+    .await?;
+
+    helpers::assert_file_has_content(
+        file1.as_file_mut(),
+        &helpers::platform_line("i can eat glass, it will not hurt me\n"),
+    )?;
+
+    helpers::assert_file_has_content(
+        file2.as_file_mut(),
+        &helpers::platform_line("i can eat glass, it will not hurt me\n"),
+    )?;
+
+    Ok(())
+}
+
+#[tokio::test]
 async fn test_write_fail_new_path() -> anyhow::Result<()> {
     let file = helpers::new_readonly_tempfile()?;
 
     test_key_sequences(
-        &mut Application::new(Args::default(), Config::default())?,
+        &mut AppBuilder::new().build()?,
         vec![
             (
                 None,
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 0daa983f..78c6d032 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -83,6 +83,18 @@ impl Serialize for Mode {
     }
 }
 
+/// A snapshot of the text of a document that we want to write out to disk
+#[derive(Debug, Clone)]
+pub struct DocumentSavedEvent {
+    pub revision: usize,
+    pub doc_id: DocumentId,
+    pub path: PathBuf,
+    pub text: Rope,
+}
+
+pub type DocumentSavedEventResult = Result<DocumentSavedEvent, anyhow::Error>;
+pub type DocumentSavedEventFuture = BoxFuture<'static, DocumentSavedEventResult>;
+
 pub struct Document {
     pub(crate) id: DocumentId,
     text: Rope,
@@ -492,45 +504,61 @@ impl Document {
         Some(fut.boxed())
     }
 
-    pub fn save(&mut self, force: bool) -> impl Future<Output = Result<(), anyhow::Error>> {
-        self.save_impl::<futures_util::future::Ready<_>>(None, force)
-    }
-
-    pub fn format_and_save(
+    pub fn save<P: Into<PathBuf>>(
         &mut self,
-        formatting: Option<impl Future<Output = Result<Transaction, FormatterError>>>,
+        path: Option<P>,
         force: bool,
-    ) -> impl Future<Output = anyhow::Result<()>> {
-        self.save_impl(formatting, force)
+    ) -> Result<
+        impl Future<Output = Result<DocumentSavedEvent, anyhow::Error>> + 'static + Send,
+        anyhow::Error,
+    > {
+        let path = path.map(|path| path.into());
+        self.save_impl(path, force)
+
+        // futures_util::future::Ready<_>,
     }
 
-    // TODO: do we need some way of ensuring two save operations on the same doc can't run at once?
-    // or is that handled by the OS/async layer
     /// The `Document`'s text is encoded according to its encoding and written to the file located
     /// at its `path()`.
-    ///
-    /// If `formatting` is present, it supplies some changes that we apply to the text before saving.
-    fn save_impl<F: Future<Output = Result<Transaction, FormatterError>>>(
+    fn save_impl(
         &mut self,
-        formatting: Option<F>,
+        path: Option<PathBuf>,
         force: bool,
-    ) -> impl Future<Output = Result<(), anyhow::Error>> {
+    ) -> Result<
+        impl Future<Output = Result<DocumentSavedEvent, anyhow::Error>> + 'static + Send,
+        anyhow::Error,
+    > {
+        log::debug!(
+            "submitting save of doc '{:?}'",
+            self.path().map(|path| path.to_string_lossy())
+        );
+
         // we clone and move text + path into the future so that we asynchronously save the current
         // state without blocking any further edits.
+        let text = self.text().clone();
 
-        let mut text = self.text().clone();
-        let path = self.path.clone().expect("Can't save with no path set!");
-        let identifier = self.identifier();
+        let path = match path {
+            Some(path) => helix_core::path::get_canonicalized_path(&path)?,
+            None => {
+                if self.path.is_none() {
+                    bail!("Can't save with no path set!");
+                }
 
+                self.path.as_ref().unwrap().clone()
+            }
+        };
+
+        let identifier = self.path().map(|_| self.identifier());
         let language_server = self.language_server.clone();
 
         // mark changes up to now as saved
-        self.reset_modified();
+        let current_rev = self.get_current_revision();
+        let doc_id = self.id();
 
         let encoding = self.encoding;
 
         // We encode the file according to the `Document`'s encoding.
-        async move {
+        let future = async move {
             use tokio::fs::File;
             if let Some(parent) = path.parent() {
                 // TODO: display a prompt asking the user if the directories should be created
@@ -543,39 +571,34 @@ impl Document {
                 }
             }
 
-            if let Some(fmt) = formatting {
-                match fmt.await {
-                    Ok(transaction) => {
-                        let success = transaction.changes().apply(&mut text);
-                        if !success {
-                            // This shouldn't happen, because the transaction changes were generated
-                            // from the same text we're saving.
-                            log::error!("failed to apply format changes before saving");
-                        }
-                    }
-                    Err(err) => {
-                        // formatting failed: report error, and save file without modifications
-                        log::error!("{}", err);
-                    }
-                }
-            }
-
-            let mut file = File::create(path).await?;
+            let mut file = File::create(&path).await?;
             to_writer(&mut file, encoding, &text).await?;
 
+            let event = DocumentSavedEvent {
+                revision: current_rev,
+                doc_id,
+                path,
+                text: text.clone(),
+            };
+
             if let Some(language_server) = language_server {
                 if !language_server.is_initialized() {
-                    return Ok(());
+                    return Ok(event);
                 }
-                if let Some(notification) =
-                    language_server.text_document_did_save(identifier, &text)
-                {
-                    notification.await?;
+
+                if let Some(identifier) = identifier {
+                    if let Some(notification) =
+                        language_server.text_document_did_save(identifier, &text)
+                    {
+                        notification.await?;
+                    }
                 }
             }
 
-            Ok(())
-        }
+            Ok(event)
+        };
+
+        Ok(future)
     }
 
     /// Detect the programming language based on the file type.
@@ -930,6 +953,12 @@ impl Document {
         let history = self.history.take();
         let current_revision = history.current_revision();
         self.history.set(history);
+        log::debug!(
+            "id {} modified - last saved: {}, current: {}",
+            self.id,
+            self.last_saved_revision,
+            current_revision
+        );
         current_revision != self.last_saved_revision || !self.changes.is_empty()
     }
 
@@ -941,6 +970,30 @@ impl Document {
         self.last_saved_revision = current_revision;
     }
 
+    /// Set the document's latest saved revision to the given one.
+    pub fn set_last_saved_revision(&mut self, rev: usize) {
+        log::debug!(
+            "doc {} revision updated {} -> {}",
+            self.id,
+            self.last_saved_revision,
+            rev
+        );
+        self.last_saved_revision = rev;
+    }
+
+    /// Get the document's latest saved revision.
+    pub fn get_last_saved_revision(&mut self) -> usize {
+        self.last_saved_revision
+    }
+
+    /// Get the current revision number
+    pub fn get_current_revision(&mut self) -> usize {
+        let history = self.history.take();
+        let current_revision = history.current_revision();
+        self.history.set(history);
+        current_revision
+    }
+
     /// Corresponding language scope name. Usually `source.<lang>`.
     pub fn language_scope(&self) -> Option<&str> {
         self.language
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index e9a3c639..cd2b1ad4 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,6 +1,6 @@
 use crate::{
     clipboard::{get_clipboard_provider, ClipboardProvider},
-    document::Mode,
+    document::{DocumentSavedEventFuture, DocumentSavedEventResult, Mode},
     graphics::{CursorKind, Rect},
     info::Info,
     input::KeyEvent,
@@ -9,8 +9,9 @@ use crate::{
     Document, DocumentId, View, ViewId,
 };
 
-use futures_util::future;
 use futures_util::stream::select_all::SelectAll;
+use futures_util::{future, StreamExt};
+use helix_lsp::Call;
 use tokio_stream::wrappers::UnboundedReceiverStream;
 
 use std::{
@@ -28,7 +29,7 @@ use tokio::{
     time::{sleep, Duration, Instant, Sleep},
 };
 
-use anyhow::Error;
+use anyhow::{anyhow, bail, Error};
 
 pub use helix_core::diagnostic::Severity;
 pub use helix_core::register::Registers;
@@ -65,7 +66,7 @@ where
     )
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct FilePickerConfig {
     /// IgnoreOptions
@@ -172,7 +173,7 @@ pub struct Config {
     pub color_modes: bool,
 }
 
-#[derive(Debug, Default, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 pub struct TerminalConfig {
     pub command: String,
@@ -225,7 +226,7 @@ pub fn get_terminal_provider() -> Option<TerminalConfig> {
     None
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case", deny_unknown_fields)]
 pub struct LspConfig {
     /// Display LSP progress messages below statusline
@@ -246,7 +247,7 @@ impl Default for LspConfig {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct SearchConfig {
     /// Smart case: Case insensitive searching unless pattern contains upper case characters. Defaults to true.
@@ -255,7 +256,7 @@ pub struct SearchConfig {
     pub wrap_around: bool,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct StatusLineConfig {
     pub left: Vec<StatusLineElement>,
@@ -279,7 +280,7 @@ impl Default for StatusLineConfig {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct ModeConfig {
     pub normal: String,
@@ -458,7 +459,7 @@ impl std::str::FromStr for GutterType {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(default)]
 pub struct WhitespaceConfig {
     pub render: WhitespaceRender,
@@ -643,12 +644,21 @@ pub struct Breakpoint {
     pub log_message: Option<String>,
 }
 
+use futures_util::stream::{Flatten, Once};
+
 pub struct Editor {
     /// Current editing mode.
     pub mode: Mode,
     pub tree: Tree,
     pub next_document_id: DocumentId,
     pub documents: BTreeMap<DocumentId, Document>,
+
+    // We Flatten<> to resolve the inner DocumentSavedEventFuture. For that we need a stream of streams, hence the Once<>.
+    // https://stackoverflow.com/a/66875668
+    pub saves: HashMap<DocumentId, UnboundedSender<Once<DocumentSavedEventFuture>>>,
+    pub save_queue: SelectAll<Flatten<UnboundedReceiverStream<Once<DocumentSavedEventFuture>>>>,
+    pub write_count: usize,
+
     pub count: Option<std::num::NonZeroUsize>,
     pub selected_register: Option<char>,
     pub registers: Registers,
@@ -688,6 +698,15 @@ pub struct Editor {
     pub config_events: (UnboundedSender<ConfigEvent>, UnboundedReceiver<ConfigEvent>),
 }
 
+#[derive(Debug)]
+pub enum EditorEvent {
+    DocumentSaved(DocumentSavedEventResult),
+    ConfigEvent(ConfigEvent),
+    LanguageServerMessage((usize, Call)),
+    DebuggerEvent(dap::Payload),
+    IdleTimer,
+}
+
 #[derive(Debug, Clone)]
 pub enum ConfigEvent {
     Refresh,
@@ -719,6 +738,8 @@ pub enum CloseError {
     DoesNotExist,
     /// Buffer is modified
     BufferModified(String),
+    /// Document failed to save
+    SaveError(anyhow::Error),
 }
 
 impl Editor {
@@ -739,6 +760,9 @@ impl Editor {
             tree: Tree::new(area),
             next_document_id: DocumentId::default(),
             documents: BTreeMap::new(),
+            saves: HashMap::new(),
+            save_queue: SelectAll::new(),
+            write_count: 0,
             count: None,
             selected_register: None,
             macro_recording: None,
@@ -804,12 +828,16 @@ impl Editor {
 
     #[inline]
     pub fn set_status<T: Into<Cow<'static, str>>>(&mut self, status: T) {
-        self.status_msg = Some((status.into(), Severity::Info));
+        let status = status.into();
+        log::debug!("editor status: {}", status);
+        self.status_msg = Some((status, Severity::Info));
     }
 
     #[inline]
     pub fn set_error<T: Into<Cow<'static, str>>>(&mut self, error: T) {
-        self.status_msg = Some((error.into(), Severity::Error));
+        let error = error.into();
+        log::error!("editor error: {}", error);
+        self.status_msg = Some((error, Severity::Error));
     }
 
     #[inline]
@@ -1034,6 +1062,13 @@ impl Editor {
             DocumentId(unsafe { NonZeroUsize::new_unchecked(self.next_document_id.0.get() + 1) });
         doc.id = id;
         self.documents.insert(id, doc);
+
+        let (save_sender, save_receiver) = tokio::sync::mpsc::unbounded_channel();
+        self.saves.insert(id, save_sender);
+
+        let stream = UnboundedReceiverStream::new(save_receiver).flatten();
+        self.save_queue.push(stream);
+
         id
     }
 
@@ -1080,16 +1115,19 @@ impl Editor {
     }
 
     pub fn close_document(&mut self, doc_id: DocumentId, force: bool) -> Result<(), CloseError> {
-        let doc = match self.documents.get(&doc_id) {
+        let doc = match self.documents.get_mut(&doc_id) {
             Some(doc) => doc,
             None => return Err(CloseError::DoesNotExist),
         };
-
         if !force && doc.is_modified() {
             return Err(CloseError::BufferModified(doc.display_name().into_owned()));
         }
 
+        // This will also disallow any follow-up writes
+        self.saves.remove(&doc_id);
+
         if let Some(language_server) = doc.language_server() {
+            // TODO: track error
             tokio::spawn(language_server.text_document_did_close(doc.identifier()));
         }
 
@@ -1152,6 +1190,32 @@ impl Editor {
         Ok(())
     }
 
+    pub fn save<P: Into<PathBuf>>(
+        &mut self,
+        doc_id: DocumentId,
+        path: Option<P>,
+        force: bool,
+    ) -> anyhow::Result<()> {
+        // convert a channel of futures to pipe into main queue one by one
+        // via stream.then() ? then push into main future
+
+        let path = path.map(|path| path.into());
+        let doc = doc_mut!(self, &doc_id);
+        let future = doc.save(path, force)?;
+
+        use futures_util::stream;
+
+        self.saves
+            .get(&doc_id)
+            .ok_or_else(|| anyhow::format_err!("saves are closed for this document!"))?
+            .send(stream::once(Box::pin(future)))
+            .map_err(|err| anyhow!("failed to send save event: {}", err))?;
+
+        self.write_count += 1;
+
+        Ok(())
+    }
+
     pub fn resize(&mut self, area: Rect) {
         if self.tree.resize(area) {
             self._refresh();
@@ -1252,14 +1316,14 @@ impl Editor {
         }
     }
 
-    /// Closes language servers with timeout. The default timeout is 500 ms, use
+    /// Closes language servers with timeout. The default timeout is 10000 ms, use
     /// `timeout` parameter to override this.
     pub async fn close_language_servers(
         &self,
         timeout: Option<u64>,
     ) -> Result<(), tokio::time::error::Elapsed> {
         tokio::time::timeout(
-            Duration::from_millis(timeout.unwrap_or(500)),
+            Duration::from_millis(timeout.unwrap_or(3000)),
             future::join_all(
                 self.language_servers
                     .iter_clients()
@@ -1269,4 +1333,48 @@ impl Editor {
         .await
         .map(|_| ())
     }
+
+    pub async fn wait_event(&mut self) -> EditorEvent {
+        tokio::select! {
+            biased;
+
+            Some(event) = self.save_queue.next() => {
+                self.write_count -= 1;
+                EditorEvent::DocumentSaved(event)
+            }
+            Some(config_event) = self.config_events.1.recv() => {
+                EditorEvent::ConfigEvent(config_event)
+            }
+            Some(message) = self.language_servers.incoming.next() => {
+                EditorEvent::LanguageServerMessage(message)
+            }
+            Some(event) = self.debugger_events.next() => {
+                EditorEvent::DebuggerEvent(event)
+            }
+            _ = &mut self.idle_timer => {
+                EditorEvent::IdleTimer
+            }
+        }
+    }
+
+    pub async fn flush_writes(&mut self) -> anyhow::Result<()> {
+        while self.write_count > 0 {
+            if let Some(save_event) = self.save_queue.next().await {
+                self.write_count -= 1;
+
+                let save_event = match save_event {
+                    Ok(event) => event,
+                    Err(err) => {
+                        self.set_error(err.to_string());
+                        bail!(err);
+                    }
+                };
+
+                let doc = doc_mut!(self, &save_event.doc_id);
+                doc.set_last_saved_revision(save_event.revision);
+            }
+        }
+
+        Ok(())
+    }
 }