Add settings to ignore backticks in AI code completion

fixed #14461

packages/ai-code-completion/src/browser/ai-code-completion-frontend-module.ts

@@ -16,7 +16,7 @@
 
 import { ILogger } from '@theia/core';
 import { ContainerModule } from '@theia/core/shared/inversify';
-import { CodeCompletionAgent, CodeCompletionAgentImpl } from '../common/code-completion-agent';
+import { CodeCompletionAgent, CodeCompletionAgentImpl } from './code-completion-agent';
 import { AIFrontendApplicationContribution } from './ai-code-frontend-application-contribution';
 import { FrontendApplicationContribution, KeybindingContribution, PreferenceContribution } from '@theia/core/lib/browser';
 import { Agent } from '@theia/ai-core';

packages/ai-code-completion/src/browser/ai-code-completion-preference.ts

@@ -20,6 +20,7 @@ import { AI_CORE_PREFERENCES_TITLE } from '@theia/ai-core/lib/browser/ai-core-pr
 export const PREF_AI_INLINE_COMPLETION_ENABLE = 'ai-features.codeCompletion.enableCodeCompletion';
 export const PREF_AI_INLINE_COMPLETION_AUTOMATIC_ENABLE = 'ai-features.codeCompletion.automaticCodeCompletion';
 export const PREF_AI_INLINE_COMPLETION_EXCLUDED_EXTENSIONS = 'ai-features.codeCompletion.excludedFileExtensions';
+export const PREF_AI_INLINE_COMPLETION_STRIP_BACKTICKS = 'ai-features.codeCompletion.stripBackticks';
 
 export const AICodeCompletionPreferencesSchema: PreferenceSchema = {
     type: 'object',
@@ -40,6 +41,14 @@ export const AICodeCompletionPreferencesSchema: PreferenceSchema = {
                 type: 'string'
             },
             default: []
+        },
+        [PREF_AI_INLINE_COMPLETION_STRIP_BACKTICKS]: {
+            title: 'Strip Backticks from Inline Completions',
+            type: 'boolean',
+            description: 'Remove surrounding backticks from the code returned by some LLMs. If a backtick is detected, all content after the closing\
+             backtick is stripped as well. This setting helps ensure plain code is returned when language models use markdown-like formatting.',
+            default: true
         }
+
     }
 };

packages/ai-code-completion/src/browser/ai-code-inline-completion-provider.ts

@@ -17,7 +17,7 @@
 import * as monaco from '@theia/monaco-editor-core';
 
 import { inject, injectable } from '@theia/core/shared/inversify';
-import { CodeCompletionAgent } from '../common/code-completion-agent';
+import { CodeCompletionAgent } from './code-completion-agent';
 import { AgentService } from '@theia/ai-core';
 
 @injectable()

packages/ai-code-completion/src/browser/code-completion-agent.spec.ts

@@ -0,0 +1,67 @@
+// *****************************************************************************
+// Copyright (C) 2024 EclipseSource GmbH.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0.
+//
+// This Source Code may also be made available under the following Secondary
+// Licenses when the conditions for such availability set forth in the Eclipse
+// Public License v. 2.0 are satisfied: GNU General Public License, version 2
+// with the GNU Classpath Exception which is available at
+// https://www.gnu.org/software/classpath/license.html.
+//
+// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
+// *****************************************************************************
+
+import { expect } from 'chai';
+import { CodeCompletionAgentImpl } from './code-completion-agent';
+
+describe('CodeCompletionAgentImpl', () => {
+    class TestableCodeCompletionAgent extends CodeCompletionAgentImpl {
+        public stripBackticksForTest(text: string): string {
+            return this.stripBackticks(text);
+        }
+    }
+    const agent = new TestableCodeCompletionAgent();
+
+    describe('stripBackticks', () => {
+
+        it('should remove surrounding backticks and language (TypeScript)', () => {
+            const input = '```TypeScript\nconsole.log(\"Hello, World!\");```';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('console.log("Hello, World!");');
+        });
+
+        it('should remove surrounding backticks and language (md)', () => {
+            const input = '```md\nconsole.log(\"Hello, World!\");```';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('console.log("Hello, World!");');
+        });
+
+        it('should remove all text after second occurrence of backticks', () => {
+            const input = '```js\nlet x = 10;\n```\nTrailing text should be removed```';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('let x = 10;');
+        });
+
+        it('should return the text unchanged if no surrounding backticks', () => {
+            const input = 'console.log(\"Hello, World!\");';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('console.log("Hello, World!");');
+        });
+
+        it('should remove surrounding backticks without language', () => {
+            const input = '```\nconsole.log(\"Hello, World!\");```';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('console.log("Hello, World!");');
+        });
+
+        it('should handle text starting with backticks but no second delimiter', () => {
+            const input = '```python\nprint(\"Hello, World!\")';
+            const output = agent.stripBackticksForTest(input);
+            expect(output).to.equal('print("Hello, World!")');
+        });
+
+    });
+});

packages/ai-code-completion/src/common/code-completion-agent.ts → packages/ai-code-completion/src/browser/code-completion-agent.ts

@@ -21,6 +21,8 @@ import {
 import { generateUuid, ILogger } from '@theia/core';
 import { inject, injectable, named } from '@theia/core/shared/inversify';
 import * as monaco from '@theia/monaco-editor-core';
+import { PREF_AI_INLINE_COMPLETION_STRIP_BACKTICKS } from './ai-code-completion-preference';
+import { PreferenceService } from '@theia/core/lib/browser';
 
 export const CodeCompletionAgent = Symbol('CodeCompletionAgent');
 export interface CodeCompletionAgent extends Agent {
@@ -30,6 +32,10 @@ export interface CodeCompletionAgent extends Agent {
 
 @injectable()
 export class CodeCompletionAgentImpl implements CodeCompletionAgent {
+
+    @inject(PreferenceService)
+    protected readonly preferenceService: PreferenceService;
+
     async provideInlineCompletions(
         model: monaco.editor.ITextModel,
         position: monaco.Position,
@@ -97,23 +103,39 @@ export class CodeCompletionAgentImpl implements CodeCompletionAgent {
         if (token.isCancellationRequested) {
             return undefined;
         }
-        const completionText = await getTextOfResponse(response);
+        let completionText = await getTextOfResponse(response);
+
         if (token.isCancellationRequested) {
             return undefined;
         }
+
         this.recordingService.recordResponse({
             agentId: this.id,
             sessionId,
             requestId,
             response: completionText,
         });
 
+        if (this.preferenceService.get<boolean>(PREF_AI_INLINE_COMPLETION_STRIP_BACKTICKS, true)) {
+            completionText = this.stripBackticks(completionText);
+        }
+
         return {
             items: [{ insertText: completionText }],
             enableForwardStability: true,
         };
     }
 
+    protected stripBackticks(text: string): string {
+        if (text.startsWith('```')) {
+            // Remove the first backticks and any language identifier
+            const startRemoved = text.slice(3).replace(/^\w*\n/, '');
+            const secondBacktickIndex = startRemoved.indexOf('```');
+            return secondBacktickIndex !== -1 ? startRemoved.slice(0, secondBacktickIndex).trim() : startRemoved.trim();
+        }
+        return text;
+    }
+
     @inject(ILogger)
     @named('code-completion-agent')
     protected logger: ILogger;