3 files changed, 51 insertions, 2 deletions

diff --git a/editors/code/src/commands/index.ts b/editors/code/src/commands/index.ts
index 2496c7ff8..d78a64c3e 100644
--- a/editors/code/src/commands/index.ts
+++ b/editors/code/src/commands/index.ts
@@ -2,6 +2,7 @@ import * as applySourceChange from './apply_source_change';
 import * as extendSelection from './extend_selection';
 import * as joinLines from './join_lines';
 import * as matchingBrace from './matching_brace';
+import * as on_enter from './on_enter';
 import * as parentModule from './parent_module';
 import * as runnables from './runnables';
 import * as syntaxTree from './syntaxTree';
@@ -13,5 +14,6 @@ export {
     matchingBrace,
     parentModule,
     runnables,
-    syntaxTree
+    syntaxTree,
+    on_enter,
 };
diff --git a/editors/code/src/commands/on_enter.ts b/editors/code/src/commands/on_enter.ts
new file mode 100644
index 000000000..2666797fe
--- /dev/null
+++ b/editors/code/src/commands/on_enter.ts
@@ -0,0 +1,29 @@
+import * as vscode from 'vscode';
+import * as lc from 'vscode-languageclient';
+import { Server } from '../server';
+import { handle as applySourceChange, SourceChange } from './apply_source_change';
+
+interface OnEnterParams {
+    textDocument: lc.TextDocumentIdentifier;
+    position: lc.Position;
+}
+
+export async function handle(event: { text: string }): Promise<boolean> {
+    const editor = vscode.window.activeTextEditor;
+    if (editor == null || editor.document.languageId !== 'rust' || event.text !== '\n') {
+        return false;
+    }
+    const request: OnEnterParams = {
+        textDocument: { uri: editor.document.uri.toString() },
+        position: Server.client.code2ProtocolConverter.asPosition(editor.selection.active),
+    };
+    const change = await Server.client.sendRequest<undefined | SourceChange>(
+        'm/onEnter',
+        request
+    );
+    if (!change) {
+        return false;
+    }
+    await applySourceChange(change);
+    return true
+}
diff --git a/editors/code/src/extension.ts b/editors/code/src/extension.ts
index 81e1107a0..3e5767535 100644
--- a/editors/code/src/extension.ts
+++ b/editors/code/src/extension.ts
@@ -15,6 +15,23 @@ export function activate(context: vscode.ExtensionContext) {
     function registerCommand(name: string, f: any) {
         disposeOnDeactivation(vscode.commands.registerCommand(name, f));
     }
+    function overrideCommand(
+
+        name: string,
+        f: (...args: any[]) => Promise<boolean>,
+    ) {
+        const defaultCmd = `default:${name}`;
+        const original = async (...args: any[]) => await vscode.commands.executeCommand(defaultCmd, ...args);
+        registerCommand(name, async (...args: any[]) => {
+            const editor = vscode.window.activeTextEditor;
+            if (!editor || !editor.document || editor.document.languageId !== 'rust') {
+                return await original(...args);
+            }
+            if (!await f(...args)) {
+                return await original(...args);
+            }
+        })
+    }
 
     // Commands are requests from vscode to the language server
     registerCommand('ra-lsp.syntaxTree', commands.syntaxTree.handle);
@@ -27,11 +44,12 @@ export function activate(context: vscode.ExtensionContext) {
         'ra-lsp.applySourceChange',
         commands.applySourceChange.handle
     );
+    overrideCommand('type', commands.on_enter.handle)
 
     // Notifications are events triggered by the language server
     const allNotifications: Iterable<
         [string, lc.GenericNotificationHandler]
-    > = [['m/publishDecorations', notifications.publishDecorations.handle]];
+        > = [['m/publishDecorations', notifications.publishDecorations.handle]];
 
     // The events below are plain old javascript events, triggered and handled by vscode
     vscode.window.onDidChangeActiveTextEditor(