test: interactive test for read write tools sequential flow (#10323)

Co-authored-by: Taneja Hriday <hridayt@google.com>

integration-tests/file-system-interactive.test.ts

@@ -0,0 +1,86 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { expect, describe, it, beforeEach, afterEach } from 'vitest';
+import { TestRig, type, printDebugInfo } from './test-helper.js';
+
+describe('Interactive file system', () => {
+  let rig: TestRig;
+
+  beforeEach(() => {
+    rig = new TestRig();
+  });
+
+  afterEach(async () => {
+    await rig.cleanup();
+  });
+
+  it.skipIf(process.platform === 'win32')(
+    'should perform a read-then-write sequence',
+    async () => {
+      const fileName = 'version.txt';
+      await rig.setup('interactive-read-then-write');
+      rig.createFile(fileName, '1.0.0');
+
+      const { ptyProcess } = rig.runInteractive();
+
+      const authDialogAppeared = await rig.waitForText(
+        'How would you like to authenticate',
+        5000,
+      );
+
+      // select the second option if auth dialog come's up
+      if (authDialogAppeared) {
+        ptyProcess.write('2');
+      }
+
+      // Wait for the app to be ready
+      const isReady = await rig.waitForText('Type your message', 15000);
+      expect(
+        isReady,
+        'CLI did not start up in interactive mode correctly',
+      ).toBe(true);
+
+      // Step 1: Read the file
+      const readPrompt = `Read the version from ${fileName}`;
+      await type(ptyProcess, readPrompt);
+      await type(ptyProcess, '\r');
+
+      const readCall = await rig.waitForToolCall('read_file', 30000);
+      expect(readCall, 'Expected to find a read_file tool call').toBe(true);
+
+      const containsExpectedVersion = await rig.waitForText('1.0.0', 15000);
+      expect(
+        containsExpectedVersion,
+        'Expected to see version "1.0.0" in output',
+      ).toBe(true);
+
+      // Step 2: Write the file
+      const writePrompt = `now change the version to 1.0.1 in the file`;
+      await type(ptyProcess, writePrompt);
+      await type(ptyProcess, '\r');
+
+      const toolCall = await rig.waitForAnyToolCall(
+        ['write_file', 'replace'],
+        30000,
+      );
+
+      if (!toolCall) {
+        printDebugInfo(rig, rig._interactiveOutput, {
+          toolCall,
+        });
+      }
+
+      expect(
+        toolCall,
+        'Expected to find a write_file or replace tool call',
+      ).toBe(true);
+
+      const newFileContent = rig.readFile(fileName);
+      expect(newFileContent).toBe('1.0.1');
+    },
+  );
+});

integration-tests/file-system.test.ts

@@ -253,7 +253,6 @@ describe('file-system', () => {
     // Final verification: ensure the file was not created.
     const filePath = path.join(rig.testDir!, fileName);
     const fileExists = existsSync(filePath);
-
     expect(fileExists, 'The non-existent file should not be created').toBe(
       false,
     );