Merge pull request #160 from tech-sushant/percy-file-support

feat: Percy test file handling by supporting specific file paths

Author: gaurav-singh-9227

src/index.ts

@@ -51,3 +51,4 @@ process.on("exit", () => {
 export { setLogger } from "./logger.js";
 export { BrowserStackMcpServer } from "./server-factory.js";
 export { trackMCP } from "./lib/instrumentation.js";
+export const PackageJsonVersion = packageJson.version;

src/lib/inmemory-store.ts

@@ -1,2 +1,13 @@
 export const signedUrlMap = new Map<string, object>();
-export const testFilePathsMap = new Map<string, string[]>();
+
+let _storedPercyResults: any = null;
+
+export const storedPercyResults = {
+  get: () => _storedPercyResults,
+  set: (value: any) => {
+    _storedPercyResults = value;
+  },
+  clear: () => {
+    _storedPercyResults = null;
+  },
+};

src/tools/add-percy-snapshots.ts

@@ -1,31 +1,39 @@
-import { testFilePathsMap } from "../lib/inmemory-store.js";
+import { storedPercyResults } from "../lib/inmemory-store.js";
 import { updateFileAndStep } from "./percy-snapshot-utils/utils.js";
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 import { percyWebSetupInstructions } from "../tools/sdk-utils/percy-web/handler.js";
 
 export async function updateTestsWithPercyCommands(args: {
-  uuid: string;
   index: number;
 }): Promise<CallToolResult> {
-  const { uuid, index } = args;
-  const filePaths = testFilePathsMap.get(uuid);
-
-  if (!filePaths) {
-    throw new Error(`No test files found in memory for UUID: ${uuid}`);
+  const { index } = args;
+  const stored = storedPercyResults.get();
+  if (!stored || !stored.testFiles) {
+    throw new Error(
+      `No test files found in memory. Please call listTestFiles first.`,
+    );
   }
 
+  const fileStatusMap = stored.testFiles;
+  const filePaths = Object.keys(fileStatusMap);
+
   if (index < 0 || index >= filePaths.length) {
     throw new Error(
-      `Invalid index: ${index}. There are ${filePaths.length} files for UUID: ${uuid}`,
+      `Invalid index: ${index}. There are ${filePaths.length} files available.`,
     );
   }
+
   const result = await updateFileAndStep(
     filePaths[index],
     index,
     filePaths.length,
     percyWebSetupInstructions,
   );
 
+  const updatedStored = { ...stored };
+  updatedStored.testFiles[filePaths[index]] = true; // true = updated
+  storedPercyResults.set(updatedStored);
+
   return {
     content: result,
   };

src/tools/list-test-files.ts

@@ -1,44 +1,80 @@
 import { listTestFiles } from "./percy-snapshot-utils/detect-test-files.js";
-import { testFilePathsMap } from "../lib/inmemory-store.js";
-import crypto from "crypto";
+import { storedPercyResults } from "../lib/inmemory-store.js";
+import { updateFileAndStep } from "./percy-snapshot-utils/utils.js";
+import { percyWebSetupInstructions } from "./sdk-utils/percy-web/handler.js";
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 
-export async function addListTestFiles(args: any): Promise<CallToolResult> {
-  const { dirs, language, framework } = args;
-  let testFiles: string[] = [];
-
-  if (!dirs || dirs.length === 0) {
+export async function addListTestFiles(): Promise<CallToolResult> {
+  const storedResults = storedPercyResults.get();
+  if (!storedResults) {
     throw new Error(
-      "No directories provided to add the test files. Please provide test directories to add percy snapshot commands.",
+      "No Framework details found. Please call expandPercyVisualTesting first to fetch the framework details.",
     );
   }
 
-  for (const dir of dirs) {
-    const files = await listTestFiles({
-      language,
-      framework,
-      baseDir: dir,
-    });
+  const language = storedResults.detectedLanguage;
+  const framework = storedResults.detectedTestingFramework;
+
+  // Use stored paths from setUpPercy
+  const dirs = storedResults.folderPaths;
+  const files = storedResults.filePaths;
+
+  let testFiles: string[] = [];
+
+  if (files && files.length > 0) {
     testFiles = testFiles.concat(files);
   }
 
+  if (dirs && dirs.length > 0) {
+    for (const dir of dirs) {
+      const discoveredFiles = await listTestFiles({
+        language,
+        framework,
+        baseDir: dir,
+      });
+      testFiles = testFiles.concat(discoveredFiles);
+    }
+  }
+
+  // Validate that we have at least one test file
   if (testFiles.length === 0) {
-    throw new Error("No test files found");
+    throw new Error(
+      "No test files found. Please provide either specific file paths (files) or directory paths (dirs) containing test files.",
+    );
   }
 
-  // Generate a UUID and store the test files in memory
-  const uuid = crypto.randomUUID();
-  testFilePathsMap.set(uuid, testFiles);
+  if (testFiles.length === 1) {
+    const result = await updateFileAndStep(
+      testFiles[0],
+      0,
+      1,
+      percyWebSetupInstructions,
+    );
+    return {
+      content: result,
+    };
+  }
+
+  // For multiple files, store directly in testFiles
+  const fileStatusMap: { [key: string]: boolean } = {};
+  testFiles.forEach((file) => {
+    fileStatusMap[file] = false; // false = not updated, true = updated
+  });
+
+  // Update storedPercyResults with test files
+  const updatedStored = { ...storedResults };
+  updatedStored.testFiles = fileStatusMap;
+  storedPercyResults.set(updatedStored);
 
   return {
     content: [
       {
         type: "text",
-        text: `The Test files are stored in memory with id ${uuid} and the total number of tests files found is ${testFiles.length}. You can use this UUID to retrieve the tests file paths later.`,
+        text: `The Test files are stored in memory and the total number of tests files found is ${testFiles.length}.`,
       },
       {
         type: "text",
-        text: `You can now use the tool addPercySnapshotCommands to update the test file with Percy commands for visual testing with the UUID ${uuid}`,
+        text: `You can now use the tool addPercySnapshotCommands to update the test file with Percy commands for visual testing.`,
       },
     ],
   };

src/tools/percy-sdk.ts

@@ -18,11 +18,7 @@ import {
   PERCY_SNAPSHOT_COMMANDS_DESCRIPTION,
   SIMULATE_PERCY_CHANGE_DESCRIPTION,
 } from "./sdk-utils/common/constants.js";
-
-import {
-  ListTestFilesParamsShape,
-  UpdateTestFileWithInstructionsParams,
-} from "./percy-snapshot-utils/constants.js";
+import { UpdateTestFileWithInstructionsParams } from "./percy-snapshot-utils/constants.js";
 
 import {
   RunPercyScanParamsShape,
@@ -126,11 +122,11 @@ export function registerPercyTools(
   tools.listTestFiles = server.tool(
     "listTestFiles",
     LIST_TEST_FILES_DESCRIPTION,
-    ListTestFilesParamsShape,
-    async (args) => {
+    {},
+    async () => {
       try {
         trackMCP("listTestFiles", server.server.getClientVersion()!, config);
-        return addListTestFiles(args);
+        return addListTestFiles();
       } catch (error) {
         return handleMCPError("listTestFiles", server, config, error);
       }

src/tools/percy-snapshot-utils/constants.ts

@@ -1,30 +1,11 @@
 import { z } from "zod";
-import {
-  SDKSupportedLanguages,
-  SDKSupportedTestingFrameworks,
-} from "../sdk-utils/common/types.js";
 import { SDKSupportedLanguage } from "../sdk-utils/common/types.js";
 import { DetectionConfig } from "./types.js";
 
 export const UpdateTestFileWithInstructionsParams = {
-  uuid: z
-    .string()
-    .describe("UUID referencing the in-memory array of test file paths"),
   index: z.number().describe("Index of the test file to update"),
 };
 
-export const ListTestFilesParamsShape = {
-  dirs: z
-    .array(z.string())
-    .describe("Array of directory paths to search for test files"),
-  language: z
-    .enum(SDKSupportedLanguages as [string, ...string[]])
-    .describe("Programming language"),
-  framework: z
-    .enum(SDKSupportedTestingFrameworks as [string, ...string[]])
-    .describe("Testing framework (optional)"),
-};
-
 export const TEST_FILE_DETECTION: Record<
   SDKSupportedLanguage,
   DetectionConfig

src/tools/run-percy-scan.ts

@@ -3,6 +3,12 @@ import { PercyIntegrationTypeEnum } from "./sdk-utils/common/types.js";
 import { BrowserStackConfig } from "../lib/types.js";
 import { getBrowserStackAuth } from "../lib/get-auth.js";
 import { fetchPercyToken } from "./sdk-utils/percy-web/fetchPercyToken.js";
+import { storedPercyResults } from "../lib/inmemory-store.js";
+import {
+  getFrameworkTestCommand,
+  PERCY_FALLBACK_STEPS,
+} from "./sdk-utils/percy-web/constants.js";
+import path from "path";
 
 export async function runPercyScan(
   args: {
@@ -18,25 +24,22 @@ export async function runPercyScan(
     type: integrationType,
   });
 
-  const steps: string[] = [generatePercyTokenInstructions(percyToken)];
-
-  if (instruction) {
-    steps.push(
-      `Use the provided test command with Percy:\n${instruction}`,
-      `If this command fails or is incorrect, fall back to the default approach below.`,
-    );
-  }
-
-  steps.push(
-    `Attempt to infer the project's test command from context (high confidence commands first):
-    - Java → mvn test
-    - Python → pytest
-    - Node.js → npm test or yarn test
-    - Cypress → cypress run
-    or from package.json scripts`,
-    `Wrap the inferred command with Percy along with label: \nnpx percy exec --labels=mcp -- <test command>`,
-    `If the test command cannot be inferred confidently, ask the user directly for the correct test command.`,
-  );
+  // Check if we have stored data and project matches
+  const stored = storedPercyResults.get();
+
+  // Compute if we have updated files to run
+  const hasUpdatedFiles = checkForUpdatedFiles(stored, projectName);
+  const updatedFiles = hasUpdatedFiles ? getUpdatedFiles(stored) : [];
+
+  // Build steps array with conditional spread
+  const steps = [
+    generatePercyTokenInstructions(percyToken),
+    ...(hasUpdatedFiles ? generateUpdatedFilesSteps(stored, updatedFiles) : []),
+    ...(instruction && !hasUpdatedFiles
+      ? generateInstructionSteps(instruction)
+      : []),
+    ...(!hasUpdatedFiles ? PERCY_FALLBACK_STEPS : []),
+  ];
 
   const instructionContext = steps
     .map((step, index) => `${index + 1}. ${step}`)
@@ -59,3 +62,56 @@ export PERCY_TOKEN="${percyToken}"
 
 (For Windows: use 'setx PERCY_TOKEN "${percyToken}"' or 'set PERCY_TOKEN=${percyToken}' as appropriate.)`;
 }
+
+const toAbs = (p: string): string | undefined =>
+  p ? path.resolve(p) : undefined;
+
+function checkForUpdatedFiles(
+  stored: any, // storedPercyResults structure
+  projectName: string,
+): boolean {
+  const projectMatches = stored?.projectName === projectName;
+  return (
+    projectMatches &&
+    stored?.testFiles &&
+    Object.values(stored.testFiles).some((status) => status === true)
+  );
+}
+
+function getUpdatedFiles(stored: any): string[] {
+  const updatedFiles: string[] = [];
+  const fileStatusMap = stored.testFiles;
+
+  Object.entries(fileStatusMap).forEach(([filePath, status]) => {
+    if (status === true) {
+      updatedFiles.push(filePath);
+    }
+  });
+
+  return updatedFiles;
+}
+
+function generateUpdatedFilesSteps(
+  stored: any,
+  updatedFiles: string[],
+): string[] {
+  const filesToRun = updatedFiles.map(toAbs).filter(Boolean) as string[];
+  const { detectedLanguage, detectedTestingFramework } = stored;
+  const exampleCommand = getFrameworkTestCommand(
+    detectedLanguage,
+    detectedTestingFramework,
+  );
+
+  return [
+    `Run only the updated files with Percy:\n` +
+      `Example: ${exampleCommand} <file1> <file2> ...`,
+    `Updated files to run:\n${filesToRun.join("\n")}`,
+  ];
+}
+
+function generateInstructionSteps(instruction: string): string[] {
+  return [
+    `Use the provided test command with Percy:\n${instruction}`,
+    `If this command fails or is incorrect, fall back to the default approach below.`,
+  ];
+}

src/tools/sdk-utils/common/constants.ts

@@ -19,7 +19,7 @@ export const PERCY_REPLACE_REGEX =
   /Invoke listTestFiles\(\) with the provided directories[\s\S]*?- DO NOT STOP until you add commands in all the files or you reach end of the files\./;
 
 export const PERCY_SNAPSHOT_INSTRUCTION = `
-Invoke listTestFiles() with the provided directories from user to gather all test files in memory and obtain the generated UUID ---STEP---
+Invoke listTestFiles() with the provided directories from user to gather all test files in memory ---STEP---
 Process files in STRICT sequential order using tool addPercySnapshotCommands() with below instructions:
 - Start with index 0
 - Then index 1  

src/tools/sdk-utils/common/schema.ts

@@ -36,9 +36,16 @@ export const SetUpPercyParamsShape = {
     ),
   folderPaths: z
     .array(z.string())
+    .optional()
     .describe(
       "An array of absolute folder paths containing UI test files. If not provided, analyze codebase for UI test folders by scanning for test patterns which contain UI test cases as per framework. Return empty array if none found.",
     ),
+  filePaths: z
+    .array(z.string())
+    .optional()
+    .describe(
+      "An array of absolute file paths to specific UI test files. Use this when you want to target specific test files rather than entire folders. If not provided, will use folderPaths instead.",
+    ),
 };
 
 export const RunTestsOnBrowserStackParamsShape = {