Add support for `.geminiignore` file (#757)

5 files changed, 82 insertions, 11 deletions

diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index deb8b62b..92a929cc 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -70,6 +70,7 @@ export interface ConfigParameters {
   vertexai?: boolean;
   showMemoryUsage?: boolean;
   contextFileName?: string;
+  geminiIgnorePatterns?: string[];
   accessibility?: AccessibilitySettings;
   fileFilteringRespectGitIgnore?: boolean;
   fileFilteringAllowBuildArtifacts?: boolean;
@@ -97,6 +98,7 @@ export class Config {
   private readonly showMemoryUsage: boolean;
   private readonly accessibility: AccessibilitySettings;
   private readonly geminiClient: GeminiClient;
+  private readonly geminiIgnorePatterns: string[] = [];
   private readonly fileFilteringRespectGitIgnore: boolean;
   private readonly fileFilteringAllowBuildArtifacts: boolean;
   private fileDiscoveryService: FileDiscoveryService | null = null;
@@ -129,6 +131,9 @@ export class Config {
     if (params.contextFileName) {
       setGeminiMdFilename(params.contextFileName);
     }
+    if (params.geminiIgnorePatterns) {
+      this.geminiIgnorePatterns = params.geminiIgnorePatterns;
+    }
 
     this.toolRegistry = createToolRegistry(this);
     this.geminiClient = new GeminiClient(this);
@@ -229,6 +234,10 @@ export class Config {
     return this.geminiClient;
   }
 
+  getGeminiIgnorePatterns(): string[] {
+    return this.geminiIgnorePatterns;
+  }
+
   getFileFilteringRespectGitIgnore(): boolean {
     return this.fileFilteringRespectGitIgnore;
   }
@@ -311,7 +320,7 @@ export function createToolRegistry(config: Config): Promise<ToolRegistry> {
   };
 
   registerCoreTool(LSTool, targetDir, config);
-  registerCoreTool(ReadFileTool, targetDir);
+  registerCoreTool(ReadFileTool, targetDir, config);
   registerCoreTool(GrepTool, targetDir);
   registerCoreTool(GlobTool, targetDir, config);
   registerCoreTool(EditTool, config);
diff --git a/packages/core/src/tools/read-file.test.ts b/packages/core/src/tools/read-file.test.ts
index 8ea42134..39c22d06 100644
--- a/packages/core/src/tools/read-file.test.ts
+++ b/packages/core/src/tools/read-file.test.ts
@@ -10,6 +10,7 @@ import * as fileUtils from '../utils/fileUtils.js';
 import path from 'path';
 import os from 'os';
 import fs from 'fs'; // For actual fs operations in setup
+import { Config } from '../config/config.js';
 
 // Mock fileUtils.processSingleFileContent
 vi.mock('../utils/fileUtils', async () => {
@@ -33,7 +34,10 @@ describe('ReadFileTool', () => {
     tempRootDir = fs.mkdtempSync(
       path.join(os.tmpdir(), 'read-file-tool-root-'),
     );
-    tool = new ReadFileTool(tempRootDir);
+    const mockConfigInstance = {
+      getGeminiIgnorePatterns: () => ['**/foo.bar', 'foo.baz', 'foo.*'],
+    } as Config;
+    tool = new ReadFileTool(tempRootDir, mockConfigInstance);
     mockProcessSingleFileContent.mockReset();
   });
 
@@ -224,5 +228,15 @@ describe('ReadFileTool', () => {
         5,
       );
     });
+
+    it('should return error if path is ignored by a .geminiignore pattern', async () => {
+      const params: ReadFileToolParams = {
+        path: path.join(tempRootDir, 'foo.bar'),
+      };
+      const result = await tool.execute(params, abortSignal);
+      expect(result.returnDisplay).toContain('foo.bar');
+      expect(result.returnDisplay).toContain('foo.*');
+      expect(result.returnDisplay).not.toContain('foo.baz');
+    });
   });
 });
diff --git a/packages/core/src/tools/read-file.ts b/packages/core/src/tools/read-file.ts
index f92885ea..5c5994d7 100644
--- a/packages/core/src/tools/read-file.ts
+++ b/packages/core/src/tools/read-file.ts
@@ -5,10 +5,12 @@
  */
 
 import path from 'path';
+import micromatch from 'micromatch';
 import { SchemaValidator } from '../utils/schemaValidator.js';
 import { makeRelative, shortenPath } from '../utils/paths.js';
 import { BaseTool, ToolResult } from './tools.js';
 import { isWithinRoot, processSingleFileContent } from '../utils/fileUtils.js';
+import { Config } from '../config/config.js';
 
 /**
  * Parameters for the ReadFile tool
@@ -35,8 +37,12 @@ export interface ReadFileToolParams {
  */
 export class ReadFileTool extends BaseTool<ReadFileToolParams, ToolResult> {
   static readonly Name: string = 'read_file';
+  private readonly geminiIgnorePatterns: string[];
 
-  constructor(private rootDirectory: string) {
+  constructor(
+    private rootDirectory: string,
+    config: Config,
+  ) {
     super(
       ReadFileTool.Name,
       'ReadFile',
@@ -64,6 +70,7 @@ export class ReadFileTool extends BaseTool<ReadFileToolParams, ToolResult> {
       },
     );
     this.rootDirectory = path.resolve(rootDirectory);
+    this.geminiIgnorePatterns = config.getGeminiIgnorePatterns() || [];
   }
 
   validateToolParams(params: ReadFileToolParams): string | null {
@@ -89,6 +96,19 @@ export class ReadFileTool extends BaseTool<ReadFileToolParams, ToolResult> {
     if (params.limit !== undefined && params.limit <= 0) {
       return 'Limit must be a positive number';
     }
+
+    // Check against .geminiignore patterns
+    if (this.geminiIgnorePatterns.length > 0) {
+      const relativePath = makeRelative(params.path, this.rootDirectory);
+      if (micromatch.isMatch(relativePath, this.geminiIgnorePatterns)) {
+        // Get patterns that matched to show in the error message
+        const matchingPatterns = this.geminiIgnorePatterns.filter((p) =>
+          micromatch.isMatch(relativePath, p),
+        );
+        return `File path '${shortenPath(relativePath)}' is ignored by the following .geminiignore pattern(s):\n\n${matchingPatterns.join('\n')}`;
+      }
+    }
+
     return null;
   }
 
diff --git a/packages/core/src/tools/read-many-files.test.ts b/packages/core/src/tools/read-many-files.test.ts
index f4ecc9d0..eb647c18 100644
--- a/packages/core/src/tools/read-many-files.test.ts
+++ b/packages/core/src/tools/read-many-files.test.ts
@@ -10,10 +10,10 @@ import { describe, it, expect, beforeEach, afterEach } from 'vitest';
 import { mockControl } from '../__mocks__/fs/promises.js';
 import { ReadManyFilesTool } from './read-many-files.js';
 import { FileDiscoveryService } from '../services/fileDiscoveryService.js';
-import { Config } from '../config/config.js';
 import path from 'path';
 import fs from 'fs'; // Actual fs for setup
 import os from 'os';
+import { Config } from '../config/config.js';
 
 describe('ReadManyFilesTool', () => {
   let tool: ReadManyFilesTool;
@@ -31,6 +31,7 @@ describe('ReadManyFilesTool', () => {
     getFileFilteringRespectGitIgnore: () => true,
     getFileFilteringCustomIgnorePatterns: () => [],
     getFileFilteringAllowBuildArtifacts: () => false,
+    getGeminiIgnorePatterns: () => ['**/foo.bar', 'foo.baz', 'foo.*'],
   } as Partial<Config> as Config;
 
   beforeEach(async () => {
@@ -367,5 +368,16 @@ describe('ReadManyFilesTool', () => {
         },
       ]);
     });
+
+    it('should return error if path is ignored by a .geminiignore pattern', async () => {
+      createFile('foo.bar', '');
+      createFile('qux/foo.baz', '');
+      createFile('foo.quux', '');
+      const params = { paths: ['foo.bar', 'qux/foo.baz', 'foo.quux'] };
+      const result = await tool.execute(params, new AbortController().signal);
+      expect(result.returnDisplay).not.toContain('foo.bar');
+      expect(result.returnDisplay).toContain('qux/foo.baz');
+      expect(result.returnDisplay).not.toContain('foo.quux');
+    });
   });
 });
diff --git a/packages/core/src/tools/read-many-files.ts b/packages/core/src/tools/read-many-files.ts
index 30f70c91..718ce510 100644
--- a/packages/core/src/tools/read-many-files.ts
+++ b/packages/core/src/tools/read-many-files.ts
@@ -119,6 +119,7 @@ export class ReadManyFilesTool extends BaseTool<
   ToolResult
 > {
   static readonly Name: string = 'read_many_files';
+  private readonly geminiIgnorePatterns: string[];
 
   /**
    * Creates an instance of ReadManyFilesTool.
@@ -190,6 +191,7 @@ Use this tool when the user's query implies needing the content of several files
       parameterSchema,
     );
     this.targetDir = path.resolve(targetDir);
+    this.geminiIgnorePatterns = config.getGeminiIgnorePatterns() || [];
   }
 
   validateParams(params: ReadManyFilesParams): string | null {
@@ -242,12 +244,26 @@ Use this tool when the user's query implies needing the content of several files
     const allPatterns = [...params.paths, ...(params.include || [])];
     const pathDesc = `using patterns: \`${allPatterns.join('`, `')}\` (within target directory: \`${this.targetDir}\`)`;
 
-    let effectiveExcludes =
-      params.useDefaultExcludes !== false ? [...DEFAULT_EXCLUDES] : [];
-    if (params.exclude && params.exclude.length > 0) {
-      effectiveExcludes = [...effectiveExcludes, ...params.exclude];
+    // Determine the final list of exclusion patterns exactly as in execute method
+    const paramExcludes = params.exclude || [];
+    const paramUseDefaultExcludes = params.useDefaultExcludes !== false;
+
+    const finalExclusionPatternsForDescription: string[] =
+      paramUseDefaultExcludes
+        ? [...DEFAULT_EXCLUDES, ...paramExcludes, ...this.geminiIgnorePatterns]
+        : [...paramExcludes, ...this.geminiIgnorePatterns];
+
+    let excludeDesc = `Excluding: ${finalExclusionPatternsForDescription.length > 0 ? `patterns like \`${finalExclusionPatternsForDescription.slice(0, 2).join('`, `')}${finalExclusionPatternsForDescription.length > 2 ? '...`' : '`'}` : 'none specified'}`;
+
+    // Add a note if .geminiignore patterns contributed to the final list of exclusions
+    if (this.geminiIgnorePatterns.length > 0) {
+      const geminiPatternsInEffect = this.geminiIgnorePatterns.filter((p) =>
+        finalExclusionPatternsForDescription.includes(p),
+      ).length;
+      if (geminiPatternsInEffect > 0) {
+        excludeDesc += ` (includes ${geminiPatternsInEffect} from .geminiignore)`;
+      }
     }
-    const excludeDesc = `Excluding: ${effectiveExcludes.length > 0 ? `patterns like \`${effectiveExcludes.slice(0, 2).join('`, `')}${effectiveExcludes.length > 2 ? '...`' : '`'}` : 'none explicitly (beyond default non-text file avoidance).'}`;
 
     return `Will attempt to read and concatenate files ${pathDesc}. ${excludeDesc}. File encoding: ${DEFAULT_ENCODING}. Separator: "${DEFAULT_OUTPUT_SEPARATOR_FORMAT.replace('{filePath}', 'path/to/file.ext')}".`;
   }
@@ -285,8 +301,8 @@ Use this tool when the user's query implies needing the content of several files
     const contentParts: PartListUnion = [];
 
     const effectiveExcludes = useDefaultExcludes
-      ? [...DEFAULT_EXCLUDES, ...exclude]
-      : [...exclude];
+      ? [...DEFAULT_EXCLUDES, ...exclude, ...this.geminiIgnorePatterns]
+      : [...exclude, ...this.geminiIgnorePatterns];
 
     const searchPatterns = [...inputPatterns, ...include];
     if (searchPatterns.length === 0) {