Improve error typing.

1 files changed, 242 insertions, 0 deletions

diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
new file mode 100644
index 00000000..93e137cb
--- /dev/null
+++ b/helix-lsp/src/client.rs
@@ -0,0 +1,242 @@
+use crate::{
+    transport::{Payload, Transport},
+    Error, Notification,
+};
+
+type Result<T> = core::result::Result<T, Error>;
+
+use helix_core::{State, Transaction};
+
+// use std::collections::HashMap;
+
+use jsonrpc_core as jsonrpc;
+use lsp_types as lsp;
+use serde_json::Value;
+
+use smol::{
+    channel::{Receiver, Sender},
+    io::{BufReader, BufWriter},
+    // prelude::*,
+    process::{Child, ChildStderr, Command, Stdio},
+    Executor,
+};
+
+pub struct Client {
+    _process: Child,
+    stderr: BufReader<ChildStderr>,
+
+    outgoing: Sender<Payload>,
+    pub incoming: Receiver<Notification>,
+
+    pub request_counter: u64,
+
+    capabilities: Option<lsp::ServerCapabilities>,
+    // TODO: handle PublishDiagnostics Version
+    // diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
+}
+
+impl Client {
+    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {
+        let mut process = Command::new(cmd)
+            .args(args)
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+            .expect("Failed to start language server");
+        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?
+
+        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
+        let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
+        let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
+        let stderr = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
+
+        let (incoming, outgoing) = Transport::start(ex, reader, writer);
+
+        Client {
+            _process: process,
+            stderr,
+
+            outgoing,
+            incoming,
+
+            request_counter: 0,
+
+            capabilities: None,
+            // diagnostics: HashMap::new(),
+        }
+    }
+
+    fn next_request_id(&mut self) -> jsonrpc::Id {
+        let id = jsonrpc::Id::Num(self.request_counter);
+        self.request_counter += 1;
+        id
+    }
+
+    fn to_params(value: Value) -> Result<jsonrpc::Params> {
+        use jsonrpc::Params;
+
+        let params = match value {
+            Value::Null => Params::None,
+            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),
+            Value::Array(vec) => Params::Array(vec),
+            Value::Object(map) => Params::Map(map),
+        };
+
+        Ok(params)
+    }
+
+    pub async fn request<R: lsp::request::Request>(
+        &mut self,
+        params: R::Params,
+    ) -> Result<R::Result>
+    where
+        R::Params: serde::Serialize,
+        R::Result: core::fmt::Debug, // TODO: temporary
+    {
+        let params = serde_json::to_value(params)?;
+
+        let request = jsonrpc::MethodCall {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            id: self.next_request_id(),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        let (tx, rx) = smol::channel::bounded::<Result<Value>>(1);
+
+        self.outgoing
+            .send(Payload::Request {
+                chan: tx,
+                value: request,
+            })
+            .await
+            .map_err(|e| Error::Other(e.into()))?;
+
+        let response = rx.recv().await.map_err(|e| Error::Other(e.into()))??;
+
+        let response = serde_json::from_value(response)?;
+
+        // TODO: we should pass request to a sender thread via a channel
+        // so it can't be interleaved
+
+        // TODO: responses can be out of order, we need to register a single shot response channel
+
+        Ok(response)
+    }
+
+    pub async fn notify<R: lsp::notification::Notification>(
+        &mut self,
+        params: R::Params,
+    ) -> Result<()>
+    where
+        R::Params: serde::Serialize,
+    {
+        let params = serde_json::to_value(params)?;
+
+        let notification = jsonrpc::Notification {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        self.outgoing
+            .send(Payload::Notification(notification))
+            .await
+            .map_err(|e| Error::Other(e.into()))?;
+
+        Ok(())
+    }
+
+    // -------------------------------------------------------------------------------------------
+    // General messages
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn initialize(&mut self) -> Result<()> {
+        // TODO: delay any requests that are triggered prior to initialize
+
+        #[allow(deprecated)]
+        let params = lsp::InitializeParams {
+            process_id: Some(u64::from(std::process::id())),
+            root_path: None,
+            // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
+            root_uri: None, // set to project root in the future
+            initialization_options: None,
+            capabilities: lsp::ClientCapabilities::default(),
+            trace: None,
+            workspace_folders: None,
+            client_info: None,
+        };
+
+        let response = self.request::<lsp::request::Initialize>(params).await?;
+        self.capabilities = Some(response.capabilities);
+
+        // next up, notify<initialized>
+        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn shutdown(&mut self) -> Result<()> {
+        self.request::<lsp::request::Shutdown>(()).await
+    }
+
+    pub async fn exit(&mut self) -> Result<()> {
+        self.notify::<lsp::notification::Exit>(()).await
+    }
+
+    // -------------------------------------------------------------------------------------------
+    // Text document
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn text_document_did_open(&mut self, state: &State) -> Result<()> {
+        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
+            text_document: lsp::TextDocumentItem {
+                uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                language_id: "rust".to_string(), // TODO: hardcoded for now
+                version: state.version,
+                text: String::from(&state.doc),
+            },
+        })
+        .await
+    }
+
+    // TODO: trigger any time history.commit_revision happens
+    pub async fn text_document_did_change(
+        &mut self,
+        state: &State,
+        transaction: &Transaction,
+    ) -> Result<()> {
+        self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
+            text_document: lsp::VersionedTextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                state.version,
+            ),
+            content_changes: vec![lsp::TextDocumentContentChangeEvent {
+                // range = None -> whole document
+                range: None,        //Some(Range)
+                range_length: None, // u64 apparently deprecated
+                text: "".to_string(),
+            }], // TODO: probably need old_state here too?
+        })
+        .await
+    }
+
+    // TODO: impl into() TextDocumentIdentifier / VersionedTextDocumentIdentifier for State.
+
+    pub async fn text_document_did_close(&mut self, state: &State) -> Result<()> {
+        self.notify::<lsp::notification::DidCloseTextDocument>(lsp::DidCloseTextDocumentParams {
+            text_document: lsp::TextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+            ),
+        })
+        .await
+    }
+
+    // will_save / will_save_wait_until
+
+    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+}