5 files changed, 52 insertions, 25 deletions

diff --git a/code/.vscode/launch.json b/code/.vscode/launch.json
index 64f2c3693..5e615ad4c 100644
--- a/code/.vscode/launch.json
+++ b/code/.vscode/launch.json
@@ -9,10 +9,10 @@
             "type": "extensionHost",
             "request": "launch",
             "runtimeExecutable": "${execPath}",
-            "args": ["--extensionDevelopmentPath=${workspaceRoot}"],
+            "args": ["--extensionDevelopmentPath='./'"],
             "stopOnEntry": false,
             "sourceMaps": true,
-            "outFiles": [ "${workspaceRoot}/out/src/**/*.js" ],
+            "outFiles": [ "./out/src/**/*.js" ],
             "preLaunchTask": "npm"
         },
     ]
diff --git a/code/src/extension.ts b/code/src/extension.ts
index afcbccf63..95305db2d 100644
--- a/code/src/extension.ts
+++ b/code/src/extension.ts
@@ -111,6 +111,16 @@ function startServer() {
                 )
             }
         )
+        client.onRequest(
+            new lc.RequestType<lc.Position, void, any, any>("m/moveCursor"),
+            (params: lc.Position, token: lc.CancellationToken) => {
+                let editor = vscode.window.activeTextEditor;
+                if (editor == null) return
+                if (!editor.selection.isEmpty) return
+                let position = client.protocol2CodeConverter.asPosition(params)
+                editor.selection = new vscode.Selection(position, position);
+            }
+        )
     })
     client.start();
 }
diff --git a/crates/server/src/main_loop/handlers.rs b/crates/server/src/main_loop/handlers.rs
index d7b78b4fa..f25c64c97 100644
--- a/crates/server/src/main_loop/handlers.rs
+++ b/crates/server/src/main_loop/handlers.rs
@@ -6,7 +6,7 @@ use languageserver_types::{
     SymbolInformation, Position,
 };
 use libanalysis::{World, Query};
-use libeditor;
+use libeditor::{self, CursorPosition};
 use libsyntax2::TextUnit;
 use serde_json::{to_value, from_value};
 
@@ -195,7 +195,7 @@ pub fn handle_execute_command(
     world: World,
     path_map: PathMap,
     mut params: req::ExecuteCommandParams,
-) -> Result<req::ApplyWorkspaceEditParams> {
+) -> Result<(req::ApplyWorkspaceEditParams, Option<Position>)> {
     if params.command.as_str() != "apply_code_action" {
         bail!("unknown cmd: {:?}", params.command);
     }
@@ -209,23 +209,24 @@ pub fn handle_execute_command(
     let action_result = match arg.id {
         ActionId::FlipComma => libeditor::flip_comma(&file, arg.offset).map(|f| f()),
         ActionId::AddDerive => libeditor::add_derive(&file, arg.offset).map(|f| f()),
-    };
-    let edit = match action_result {
-        Some(action_result) => action_result.edit,
-        None => bail!("command not applicable"),
-    };
+    }.ok_or_else(|| format_err!("command not applicable"))?;
     let line_index = world.file_line_index(file_id)?;
     let mut changes = HashMap::new();
     changes.insert(
         arg.text_document.uri,
-        edit.conv_with(&line_index),
+        action_result.edit.conv_with(&line_index),
     );
     let edit = WorkspaceEdit {
         changes: Some(changes),
         document_changes: None,
     };
+    let edit = req::ApplyWorkspaceEditParams { edit };
+    let cursor_pos = match action_result.cursor_position {
+        CursorPosition::Same => None,
+        CursorPosition::Offset(offset) => Some(offset.conv_with(&line_index)),
+    };
 
-    Ok(req::ApplyWorkspaceEditParams { edit })
+    Ok((edit, cursor_pos))
 }
 
 #[derive(Serialize, Deserialize)]
diff --git a/crates/server/src/main_loop/mod.rs b/crates/server/src/main_loop/mod.rs
index 4d5dfb437..1fbcc7d1f 100644
--- a/crates/server/src/main_loop/mod.rs
+++ b/crates/server/src/main_loop/mod.rs
@@ -171,21 +171,29 @@ fn on_request(
         let path_map = path_map.clone();
         let sender = sender.clone();
         pool.execute(move || {
-            let task = match handle_execute_command(world, path_map, params) {
-                Ok(req) => match to_value(req) {
-                    Err(e) => Task::Die(e.into()),
-                    Ok(params) => {
-                        let request = RawRequest {
-                            id: 0,
-                            method: <req::ApplyWorkspaceEdit as req::ClientRequest>::METHOD.to_string(),
-                            params,
-                        };
-                        Task::Request(request)
-                    }
-                },
-                Err(e) => Task::Die(e),
+            let (edit, cursor) = match handle_execute_command(world, path_map, params) {
+                Ok(res) => res,
+                Err(e) => return sender.send(Task::Die(e)),
             };
-            sender.send(task)
+            match to_value(edit) {
+                Err(e) => return sender.send(Task::Die(e.into())),
+                Ok(params) => {
+                    let request = RawRequest {
+                        id: 0,
+                        method: <req::ApplyWorkspaceEdit as req::ClientRequest>::METHOD.to_string(),
+                        params,
+                    };
+                    sender.send(Task::Request(request))
+                }
+            }
+            if let Some(cursor) = cursor {
+                let request = RawRequest {
+                    id: 0,
+                    method: <req::MoveCursor as req::ClientRequest>::METHOD.to_string(),
+                    params: to_value(cursor).unwrap(),
+                };
+                sender.send(Task::Request(request))
+            }
         });
         Ok(())
     })?;
diff --git a/crates/server/src/req.rs b/crates/server/src/req.rs
index c3efc7489..73e82150c 100644
--- a/crates/server/src/req.rs
+++ b/crates/server/src/req.rs
@@ -101,3 +101,11 @@ pub struct Decoration {
     pub range: Range,
     pub tag: &'static str
 }
+
+pub enum MoveCursor {}
+
+impl Request for MoveCursor {
+    type Params = Position;
+    type Result = ();
+    const METHOD: &'static str = "m/moveCursor";
+}