Add search and replace function to coder (#14774)

fixed #14773

Signed-off-by: Jonas Helming <[email protected]>

packages/ai-workspace-agent/src/browser/coder-agent.ts

@@ -17,7 +17,7 @@ import { AbstractStreamParsingChatAgent, ChatAgent, SystemMessageDescription } f
 import { AgentSpecificVariables, PromptTemplate } from '@theia/ai-core';
 import { injectable } from '@theia/core/shared/inversify';
 import { FILE_CONTENT_FUNCTION_ID, GET_WORKSPACE_FILE_LIST_FUNCTION_ID, GET_WORKSPACE_DIRECTORY_STRUCTURE_FUNCTION_ID } from '../common/workspace-functions';
-import { coderReplacePromptTemplate } from '../common/coder-replace-prompt-template';
+import { CODER_DEFAULT_PROMPT_TEMPLATE_ID, getCoderReplacePromptTemplate } from '../common/coder-replace-prompt-template';
 import { WriteChangeToFileProvider } from './file-changeset-functions';
 
 @injectable()
@@ -36,14 +36,14 @@ export class CoderAgent extends AbstractStreamParsingChatAgent implements ChatAg
         }], 'chat');
         this.name = 'Coder';
         this.description = 'An AI assistant integrated into Theia IDE, designed to assist software developers with code tasks.';
-        this.promptTemplates = [coderReplacePromptTemplate];
+        this.promptTemplates = [getCoderReplacePromptTemplate(false), getCoderReplacePromptTemplate(true)];
         this.variables = [];
         this.agentSpecificVariables = [];
         this.functions = [GET_WORKSPACE_DIRECTORY_STRUCTURE_FUNCTION_ID, GET_WORKSPACE_FILE_LIST_FUNCTION_ID, FILE_CONTENT_FUNCTION_ID, WriteChangeToFileProvider.ID];
     }
 
     protected override async getSystemMessageDescription(): Promise<SystemMessageDescription | undefined> {
-        const resolvedPrompt = await this.promptService.getPrompt(coderReplacePromptTemplate.id);
+        const resolvedPrompt = await this.promptService.getPrompt(CODER_DEFAULT_PROMPT_TEMPLATE_ID);
         return resolvedPrompt ? SystemMessageDescription.fromResolvedPromptTemplate(resolvedPrompt) : undefined;
     }
 

packages/ai-workspace-agent/src/browser/content-replacer.spec.ts

@@ -0,0 +1,92 @@
+// *****************************************************************************
+// Copyright (C) 2025 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 { ContentReplacer, Replacement } from './content-replacer';
+
+describe('ContentReplacer', () => {
+    let contentReplacer: ContentReplacer;
+
+    before(() => {
+        contentReplacer = new ContentReplacer();
+    });
+
+    it('should replace content when oldContent matches exactly', () => {
+        const originalContent = 'Hello World!';
+        const replacements: Replacement[] = [
+            { oldContent: 'World', newContent: 'Universe' }
+        ];
+        const expectedContent = 'Hello Universe!';
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(expectedContent);
+        expect(result.errors).to.be.empty;
+    });
+
+    it('should replace content when oldContent matches after trimming lines', () => {
+        const originalContent = 'Line one\n   Line two   \nLine three';
+        const replacements: Replacement[] = [
+            { oldContent: 'Line two', newContent: 'Second Line' }
+        ];
+        const expectedContent = 'Line one\n   Second Line   \nLine three';
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(expectedContent);
+        expect(result.errors).to.be.empty;
+    });
+
+    it('should return an error when oldContent is not found', () => {
+        const originalContent = 'Sample content';
+        const replacements: Replacement[] = [
+            { oldContent: 'Nonexistent', newContent: 'Replacement' }
+        ];
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(originalContent);
+        expect(result.errors).to.include('Content to replace not found: "Nonexistent"');
+    });
+
+    it('should return an error when oldContent has multiple occurrences', () => {
+        const originalContent = 'Repeat Repeat Repeat';
+        const replacements: Replacement[] = [
+            { oldContent: 'Repeat', newContent: 'Once' }
+        ];
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(originalContent);
+        expect(result.errors).to.include('Multiple occurrences found for: "Repeat"');
+    });
+
+    it('should prepend newContent when oldContent is an empty string', () => {
+        const originalContent = 'Existing content';
+        const replacements: Replacement[] = [
+            { oldContent: '', newContent: 'Prepended content\n' }
+        ];
+        const expectedContent = 'Prepended content\nExisting content';
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(expectedContent);
+        expect(result.errors).to.be.empty;
+    });
+
+    it('should handle multiple replacements correctly', () => {
+        const originalContent = 'Foo Bar Baz';
+        const replacements: Replacement[] = [
+            { oldContent: 'Foo', newContent: 'FooModified' },
+            { oldContent: 'Bar', newContent: 'BarModified' },
+            { oldContent: 'Baz', newContent: 'BazModified' }
+        ];
+        const expectedContent = 'FooModified BarModified BazModified';
+        const result = contentReplacer.applyReplacements(originalContent, replacements);
+        expect(result.updatedContent).to.equal(expectedContent);
+        expect(result.errors).to.be.empty;
+    });
+});

packages/ai-workspace-agent/src/browser/content-replacer.ts

@@ -0,0 +1,126 @@
+// *****************************************************************************
+// Copyright (C) 2025 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
+// *****************************************************************************
+
+export interface Replacement {
+    oldContent: string;
+    newContent: string;
+}
+
+export class ContentReplacer {
+    /**
+     * Applies a list of replacements to the original content using a multi-step matching strategy.
+     * @param originalContent The original file content.
+     * @param replacements Array of Replacement objects.
+     * @returns An object containing the updated content and any error messages.
+     */
+    applyReplacements(originalContent: string, replacements: Replacement[]): { updatedContent: string, errors: string[] } {
+        let updatedContent = originalContent;
+        const errorMessages: string[] = [];
+
+        replacements.forEach(({ oldContent, newContent }) => {
+            // If the old content is empty, prepend the new content to the beginning of the file (e.g. in new file)
+            if (oldContent === '') {
+                updatedContent = newContent + updatedContent;
+                return;
+            }
+
+            let matchIndices = this.findExactMatches(updatedContent, oldContent);
+
+            if (matchIndices.length === 0) {
+                matchIndices = this.findLineTrimmedMatches(updatedContent, oldContent);
+            }
+
+            if (matchIndices.length === 0) {
+                errorMessages.push(`Content to replace not found: "${oldContent}"`);
+            } else if (matchIndices.length > 1) {
+                errorMessages.push(`Multiple occurrences found for: "${oldContent}"`);
+            } else {
+                updatedContent = this.replaceContentOnce(updatedContent, oldContent, newContent);
+            }
+        });
+
+        return { updatedContent, errors: errorMessages };
+    }
+
+    /**
+     * Finds all exact matches of a substring within a string.
+     * @param content The content to search within.
+     * @param search The substring to search for.
+     * @returns An array of starting indices where the exact substring is found.
+     */
+    private findExactMatches(content: string, search: string): number[] {
+        const indices: number[] = [];
+        let startIndex = 0;
+
+        while ((startIndex = content.indexOf(search, startIndex)) !== -1) {
+            indices.push(startIndex);
+            startIndex += search.length;
+        }
+
+        return indices;
+    }
+
+    /**
+     * Attempts to find matches by trimming whitespace from lines in the original content and the search string.
+     * @param content The original content.
+     * @param search The substring to search for, potentially with varying whitespace.
+     * @returns An array of starting indices where a trimmed match is found.
+     */
+    private findLineTrimmedMatches(content: string, search: string): number[] {
+        const trimmedSearch = search.trim();
+        const lines = content.split('\n');
+
+        for (let i = 0; i < lines.length; i++) {
+            const trimmedLine = lines[i].trim();
+            if (trimmedLine === trimmedSearch) {
+                // Calculate the starting index of this line in the original content
+                const startIndex = this.getLineStartIndex(content, i);
+                return [startIndex];
+            }
+        }
+
+        return [];
+    }
+
+    /**
+     * Calculates the starting index of a specific line number in the content.
+     * @param content The original content.
+     * @param lineNumber The zero-based line number.
+     * @returns The starting index of the specified line.
+     */
+    private getLineStartIndex(content: string, lineNumber: number): number {
+        const lines = content.split('\n');
+        let index = 0;
+        for (let i = 0; i < lineNumber; i++) {
+            index += lines[i].length + 1; // +1 for the newline character
+        }
+        return index;
+    }
+
+    /**
+     * Replaces the first occurrence of oldContent with newContent in the content.
+     * @param content The original content.
+     * @param oldContent The content to be replaced.
+     * @param newContent The content to replace with.
+     * @returns The content after replacement.
+     */
+    private replaceContentOnce(content: string, oldContent: string, newContent: string): string {
+        const index = content.indexOf(oldContent);
+        if (index === -1) { return content; }
+        return content.substring(0, index) + newContent + content.substring(index + oldContent.length);
+    }
+
+}

packages/ai-workspace-agent/src/browser/file-changeset-functions.ts

@@ -19,6 +19,7 @@ import { WorkspaceFunctionScope } from './workspace-functions';
 import { ChangeSetFileElementFactory } from '@theia/ai-chat/lib/browser/change-set-file-element';
 import { ChangeSetImpl, ChatRequestModelImpl } from '@theia/ai-chat';
 import { FileService } from '@theia/filesystem/lib/browser/file-service';
+import { ContentReplacer, Replacement } from './content-replacer';
 
 @injectable()
 export class WriteChangeToFileProvider implements ToolProvider {
@@ -90,3 +91,97 @@ export class WriteChangeToFileProvider implements ToolProvider {
         };
     }
 }
+
+@injectable()
+export class ReplaceContentInFileProvider implements ToolProvider {
+    static ID = 'changeSet_replaceContentInFile';
+
+    @inject(WorkspaceFunctionScope)
+    protected readonly workspaceFunctionScope: WorkspaceFunctionScope;
+
+    @inject(FileService)
+    fileService: FileService;
+
+    @inject(ChangeSetFileElementFactory)
+    protected readonly fileChangeFactory: ChangeSetFileElementFactory;
+
+    private replacer: ContentReplacer;
+
+    constructor() {
+        this.replacer = new ContentReplacer();
+    }
+
+    getTool(): ToolRequest {
+        return {
+            id: ReplaceContentInFileProvider.ID,
+            name: ReplaceContentInFileProvider.ID,
+            description: `Request to replace sections of content in an existing file by providing a list of tuples with old content to be matched and replaced.
+            Only the first matched instance of each old content in the tuples will be replaced. For deletions, use an empty new content in the tuple.\n
+            Make sure you use the same line endings and whitespace as in the original file content. The proposed changes will be applied when the user accepts.`,
+            parameters: {
+                type: 'object',
+                properties: {
+                    path: {
+                        type: 'string',
+                        description: 'The path of the file where content will be replaced.'
+                    },
+                    replacements: {
+                        type: 'array',
+                        items: {
+                            type: 'object',
+                            properties: {
+                                oldContent: {
+                                    type: 'string',
+                                    description: 'The exact content to be replaced. Must match exactly, including whitespace, comments, etc.'
+                                },
+                                newContent: {
+                                    type: 'string',
+                                    description: 'The new content to insert in place of matched old content.'
+                                }
+                            },
+                            required: ['oldContent', 'newContent']
+                        },
+                        description: 'An array of replacement objects, each containing oldContent and newContent strings.'
+                    }
+                },
+                required: ['path', 'replacements']
+            },
+            handler: async (args: string, ctx: ChatRequestModelImpl): Promise<string> => {
+                try {
+                    const { path, replacements } = JSON.parse(args) as { path: string, replacements: Replacement[] };
+                    const fileUri = await this.workspaceFunctionScope.resolveRelativePath(path);
+                    const fileContent = (await this.fileService.read(fileUri)).value.toString();
+
+                    const { updatedContent, errors } = this.replacer.applyReplacements(fileContent, replacements);
+
+                    if (errors.length > 0) {
+                        return `Errors encountered: ${errors.join('; ')}`;
+                    }
+
+                    if (updatedContent !== fileContent) {
+                        let changeSet = ctx.session.changeSet;
+                        if (!changeSet) {
+                            changeSet = new ChangeSetImpl('Changes proposed by Coder');
+                            ctx.session.setChangeSet(changeSet);
+                        }
+
+                        changeSet.addElement(
+                            this.fileChangeFactory({
+                                uri: fileUri,
+                                type: 'modify',
+                                state: 'pending',
+                                targetState: updatedContent,
+                                changeSet,
+                                chatSessionId: ctx.session.id
+                            })
+                        );
+                    }
+                    return `Proposed replacements in file ${path}. The user will review and potentially apply the changes.`;
+                } catch (error) {
+                    console.info('Error processing replacements:', error.message);
+                    return JSON.stringify({ error: error.message });
+                }
+            }
+        };
+    }
+}

packages/ai-workspace-agent/src/browser/frontend-module.ts

@@ -24,6 +24,7 @@ import { PreferenceContribution } from '@theia/core/lib/browser';
 import { WorkspacePreferencesSchema } from './workspace-preferences';
 
 import {
+    ReplaceContentInFileProvider,
     WriteChangeToFileProvider
 } from './file-changeset-functions';
 
@@ -41,4 +42,5 @@ export default new ContainerModule(bind => {
     bind(WorkspaceFunctionScope).toSelf().inSingletonScope();
 
     bind(ToolProvider).to(WriteChangeToFileProvider);
+    bind(ToolProvider).to(ReplaceContentInFileProvider);
 });