Add support for an additional exclusion file besides .gitignore and .geminiignore (#16487)

Co-authored-by: Adam Weidman <adamfweidman@google.com>

packages/cli/src/config/config.test.ts

@@ -126,10 +126,12 @@ vi.mock('@google/gemini-cli-core', async () => {
     DEFAULT_MEMORY_FILE_FILTERING_OPTIONS: {
       respectGitIgnore: false,
       respectGeminiIgnore: true,
+      customIgnoreFilePaths: [],
     },
     DEFAULT_FILE_FILTERING_OPTIONS: {
       respectGitIgnore: true,
       respectGeminiIgnore: true,
+      customIgnoreFilePaths: [],
     },
     createPolicyEngineConfig: vi.fn(async () => ({
       rules: [],
@@ -704,6 +706,9 @@ describe('loadCliConfig', () => {
     expect(config.getFileFilteringRespectGeminiIgnore()).toBe(
       DEFAULT_FILE_FILTERING_OPTIONS.respectGeminiIgnore,
     );
+    expect(config.getCustomIgnoreFilePaths()).toEqual(
+      DEFAULT_FILE_FILTERING_OPTIONS.customIgnoreFilePaths,
+    );
     expect(config.getApprovalMode()).toBe(ApprovalMode.DEFAULT);
   });
 

packages/cli/src/config/settingsSchema.test.ts

@@ -107,6 +107,14 @@ describe('SettingsSchema', () => {
         getSettingsSchema().context.properties.fileFiltering.properties
           ?.enableRecursiveFileSearch,
       ).toBeDefined();
+      expect(
+        getSettingsSchema().context.properties.fileFiltering.properties
+          ?.customIgnoreFilePaths,
+      ).toBeDefined();
+      expect(
+        getSettingsSchema().context.properties.fileFiltering.properties
+          ?.customIgnoreFilePaths.type,
+      ).toBe('array');
     });
 
     it('should have unique categories', () => {

packages/cli/src/config/settingsSchema.ts

@@ -932,6 +932,18 @@ const SETTINGS_SCHEMA = {
             description: 'Enable fuzzy search when searching for files.',
             showInDialog: true,
           },
+          customIgnoreFilePaths: {
+            type: 'array',
+            label: 'Custom Ignore File Paths',
+            category: 'Context',
+            requiresRestart: true,
+            default: [] as string[],
+            description:
+              'Additional ignore file paths to respect. These files take precedence over .geminiignore and .gitignore. Files earlier in the array take precedence over files later in the array, e.g. the first file takes precedence over the second one.',
+            showInDialog: true,
+            items: { type: 'string' },
+            mergeStrategy: MergeStrategy.UNION,
+          },
         },
       },
     },