chore: add proper pluralization handling for match in grep tool (#2344)

Co-authored-by: Allen Hutchison <adh@google.com>

docs/tools/file-system.md

@@ -159,7 +159,7 @@ The Gemini CLI provides a comprehensive suite of tools for interacting with the
   - Returns a list of matching lines, each prefixed with its file path (relative to the search directory) and line number.
 - **Output (`llmContent`):** A formatted string of matches, e.g.:
   ```
-  Found 3 match(es) for pattern "myFunction" in path "." (filter: "*.ts"):
+  Found 3 matches for pattern "myFunction" in path "." (filter: "*.ts"):
   ---
   File: src/utils.ts
   L15: export function myFunction() {

packages/core/src/tools/grep.test.ts

@@ -115,38 +115,38 @@ describe('GrepTool', () => {
       const params: GrepToolParams = { pattern: 'world' };
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 3 match(es) for pattern "world" in path "."',
+        'Found 3 matches for pattern "world" in path "."',
       );
       expect(result.llmContent).toContain('File: fileA.txt');
       expect(result.llmContent).toContain('L1: hello world');
       expect(result.llmContent).toContain('L2: second line with world');
       expect(result.llmContent).toContain('File: sub/fileC.txt');
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 3 matche(s)');
+      expect(result.returnDisplay).toBe('Found 3 matches');
     });
 
     it('should find matches in a specific path', async () => {
       const params: GrepToolParams = { pattern: 'world', path: 'sub' };
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 1 match(es) for pattern "world" in path "sub"',
+        'Found 1 match for pattern "world" in path "sub"',
       );
       expect(result.llmContent).toContain('File: fileC.txt'); // Path relative to 'sub'
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 1 matche(s)');
+      expect(result.returnDisplay).toBe('Found 1 match');
     });
 
     it('should find matches with an include glob', async () => {
       const params: GrepToolParams = { pattern: 'hello', include: '*.js' };
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 1 match(es) for pattern "hello" in path "." (filter: "*.js")',
+        'Found 1 match for pattern "hello" in path "." (filter: "*.js")',
       );
       expect(result.llmContent).toContain('File: fileB.js');
       expect(result.llmContent).toContain(
         'L2: function baz() { return "hello"; }',
       );
-      expect(result.returnDisplay).toBe('Found 1 matche(s)');
+      expect(result.returnDisplay).toBe('Found 1 match');
     });
 
     it('should find matches with an include glob and path', async () => {
@@ -161,11 +161,11 @@ describe('GrepTool', () => {
       };
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 1 match(es) for pattern "hello" in path "sub" (filter: "*.js")',
+        'Found 1 match for pattern "hello" in path "sub" (filter: "*.js")',
       );
       expect(result.llmContent).toContain('File: another.js');
       expect(result.llmContent).toContain('L1: const greeting = "hello";');
-      expect(result.returnDisplay).toBe('Found 1 matche(s)');
+      expect(result.returnDisplay).toBe('Found 1 match');
     });
 
     it('should return "No matches found" when pattern does not exist', async () => {
@@ -181,7 +181,7 @@ describe('GrepTool', () => {
       const params: GrepToolParams = { pattern: 'foo.*bar' }; // Matches 'const foo = "bar";'
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 1 match(es) for pattern "foo.*bar" in path "."',
+        'Found 1 match for pattern "foo.*bar" in path "."',
       );
       expect(result.llmContent).toContain('File: fileB.js');
       expect(result.llmContent).toContain('L1: const foo = "bar";');
@@ -191,7 +191,7 @@ describe('GrepTool', () => {
       const params: GrepToolParams = { pattern: 'HELLO' };
       const result = await grepTool.execute(params, abortSignal);
       expect(result.llmContent).toContain(
-        'Found 2 match(es) for pattern "HELLO" in path "."',
+        'Found 2 matches for pattern "HELLO" in path "."',
       );
       expect(result.llmContent).toContain('File: fileA.txt');
       expect(result.llmContent).toContain('L1: hello world');

packages/core/src/tools/grep.ts

@@ -213,7 +213,10 @@ export class GrepTool extends BaseTool<GrepToolParams, ToolResult> {
         {} as Record<string, GrepMatch[]>,
       );
 
-      let llmContent = `Found ${matches.length} match(es) for pattern "${params.pattern}" in path "${searchDirDisplay}"${params.include ? ` (filter: "${params.include}")` : ''}:\n---\n`;
+      const matchCount = matches.length;
+      const matchTerm = matchCount === 1 ? 'match' : 'matches';
+
+      let llmContent = `Found ${matchCount} ${matchTerm} for pattern "${params.pattern}" in path "${searchDirDisplay}"${params.include ? ` (filter: "${params.include}")` : ''}:\n---\n`;
 
       for (const filePath in matchesByFile) {
         llmContent += `File: ${filePath}\n`;
@@ -226,7 +229,7 @@ export class GrepTool extends BaseTool<GrepToolParams, ToolResult> {
 
       return {
         llmContent: llmContent.trim(),
-        returnDisplay: `Found ${matches.length} matche(s)`,
+        returnDisplay: `Found ${matchCount} ${matchTerm}`,
       };
     } catch (error) {
       console.error(`Error during GrepLogic execution: ${error}`);