Add on-enter handler

Now, typing doc comments is much more pleasant

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
+}