LSP code action commands (#1304)

* feat(lsp): codeAction commands

* Don't block on command call

* Fix lifetime of command execution

* Fix lint issues

4 files changed, 89 insertions, 13 deletions

diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 271fd9d5..f1de8752 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -202,7 +202,7 @@ impl Client {
                 Ok(result) => Output::Success(Success {
                     jsonrpc: Some(Version::V2),
                     id,
-                    result,
+                    result: serde_json::to_value(result)?,
                 }),
                 Err(error) => Output::Failure(Failure {
                     jsonrpc: Some(Version::V2),
@@ -800,4 +800,16 @@ impl Client {
         let response = self.request::<lsp::request::Rename>(params).await?;
         Ok(response.unwrap_or_default())
     }
+
+    pub fn command(&self, command: lsp::Command) -> impl Future<Output = Result<Value>> {
+        let params = lsp::ExecuteCommandParams {
+            command: command.command,
+            arguments: command.arguments.unwrap_or_default(),
+            work_done_progress_params: lsp::WorkDoneProgressParams {
+                work_done_token: None,
+            },
+        };
+
+        self.call::<lsp::request::ExecuteCommand>(params)
+    }
 }
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 15cae582..8fb321bc 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -203,6 +203,7 @@ pub mod util {
 #[derive(Debug, PartialEq, Clone)]
 pub enum MethodCall {
     WorkDoneProgressCreate(lsp::WorkDoneProgressCreateParams),
+    ApplyWorkspaceEdit(lsp::ApplyWorkspaceEditParams),
 }
 
 impl MethodCall {
@@ -215,6 +216,12 @@ impl MethodCall {
                     .expect("Failed to parse WorkDoneCreate params");
                 Self::WorkDoneProgressCreate(params)
             }
+            lsp::request::ApplyWorkspaceEdit::METHOD => {
+                let params: lsp::ApplyWorkspaceEditParams = params
+                    .parse()
+                    .expect("Failed to parse ApplyWorkspaceEdit params");
+                Self::ApplyWorkspaceEdit(params)
+            }
             _ => {
                 log::warn!("unhandled lsp request: {}", method);
                 return None;
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 3e0b6d59..9a46a7fe 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -1,8 +1,12 @@
 use helix_core::{merge_toml_values, syntax};
 use helix_lsp::{lsp, util::lsp_pos_to_pos, LspProgressMap};
 use helix_view::{theme, Editor};
+use serde_json::json;
 
-use crate::{args::Args, compositor::Compositor, config::Config, job::Jobs, ui};
+use crate::{
+    args::Args, commands::apply_workspace_edit, compositor::Compositor, config::Config, job::Jobs,
+    ui,
+};
 
 use log::{error, warn};
 
@@ -530,14 +534,6 @@ impl Application {
             Call::MethodCall(helix_lsp::jsonrpc::MethodCall {
                 method, params, id, ..
             }) => {
-                let language_server = match self.editor.language_servers.get_by_id(server_id) {
-                    Some(language_server) => language_server,
-                    None => {
-                        warn!("can't find language server with id `{}`", server_id);
-                        return;
-                    }
-                };
-
                 let call = match MethodCall::parse(&method, params) {
                     Some(call) => call,
                     None => {
@@ -567,8 +563,42 @@ impl Application {
                         if spinner.is_stopped() {
                             spinner.start();
                         }
+                        let language_server =
+                            match self.editor.language_servers.get_by_id(server_id) {
+                                Some(language_server) => language_server,
+                                None => {
+                                    warn!("can't find language server with id `{}`", server_id);
+                                    return;
+                                }
+                            };
+
                         tokio::spawn(language_server.reply(id, Ok(serde_json::Value::Null)));
                     }
+                    MethodCall::ApplyWorkspaceEdit(params) => {
+                        apply_workspace_edit(
+                            &mut self.editor,
+                            helix_lsp::OffsetEncoding::Utf8,
+                            &params.edit,
+                        );
+
+                        let language_server =
+                            match self.editor.language_servers.get_by_id(server_id) {
+                                Some(language_server) => language_server,
+                                None => {
+                                    warn!("can't find language server with id `{}`", server_id);
+                                    return;
+                                }
+                            };
+
+                        tokio::spawn(language_server.reply(
+                            id,
+                            Ok(json!(lsp::ApplyWorkspaceEditResponse {
+                                applied: true,
+                                failure_reason: None,
+                                failed_change: None,
+                            })),
+                        ));
+                    }
                 }
             }
             e => unreachable!("{:?}", e),
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 297b49a1..ee6a5989 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -3277,12 +3277,19 @@ pub fn code_action(cx: &mut Context) {
                     move |editor, code_action, _action| match code_action {
                         lsp::CodeActionOrCommand::Command(command) => {
                             log::debug!("code action command: {:?}", command);
-                            editor.set_error(String::from("Handling code action command is not implemented yet, see https://github.com/helix-editor/helix/issues/183"));
+                            execute_lsp_command(editor, command.clone());
                         }
                         lsp::CodeActionOrCommand::CodeAction(code_action) => {
                             log::debug!("code action: {:?}", code_action);
                             if let Some(ref workspace_edit) = code_action.edit {
-                                apply_workspace_edit(editor, offset_encoding, workspace_edit)
+                                log::debug!("edit: {:?}", workspace_edit);
+                                apply_workspace_edit(editor, offset_encoding, workspace_edit);
+                            }
+
+                            // if code action provides both edit and command first the edit
+                            // should be applied and then the command
+                            if let Some(command) = &code_action.command {
+                                execute_lsp_command(editor, command.clone());
                             }
                         }
                     },
@@ -3293,6 +3300,26 @@ pub fn code_action(cx: &mut Context) {
     )
 }
 
+pub fn execute_lsp_command(editor: &mut Editor, cmd: lsp::Command) {
+    let (_view, doc) = current!(editor);
+
+    let language_server = match doc.language_server() {
+        Some(language_server) => language_server,
+        None => return,
+    };
+
+    // the command is executed on the server and communicated back
+    // to the client asynchronously using workspace edits
+    let command_future = language_server.command(cmd);
+    tokio::spawn(async move {
+        let res = command_future.await;
+
+        if let Err(e) = res {
+            log::error!("execute LSP command: {}", e);
+        }
+    });
+}
+
 pub fn apply_document_resource_op(op: &lsp::ResourceOp) -> std::io::Result<()> {
     use lsp::ResourceOp;
     use std::fs;
@@ -3346,7 +3373,7 @@ pub fn apply_document_resource_op(op: &lsp::ResourceOp) -> std::io::Result<()> {
     }
 }
 
-fn apply_workspace_edit(
+pub fn apply_workspace_edit(
     editor: &mut Editor,
     offset_encoding: OffsetEncoding,
     workspace_edit: &lsp::WorkspaceEdit,