From 493c7892d07adda70b8d9f5fb9dd0db8f9b1a623 Mon Sep 17 00:00:00 2001
From: Melissa Liu <mellyeliu@meta.com>
Date: Sun, 12 Jan 2025 20:14:48 -0500
Subject: [PATCH] fix: fix readCache to use custom cache path when set

---
 .../__tests__/compile-stylex-folder-test.js   | 29 ++++++++++++++-----
 packages/cli/src/cache.js                     |  6 ++--
 packages/cli/src/transform.js                 |  2 +-
 3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/packages/cli/__tests__/compile-stylex-folder-test.js b/packages/cli/__tests__/compile-stylex-folder-test.js
index 2287047a..1dcf3443 100644
--- a/packages/cli/__tests__/compile-stylex-folder-test.js
+++ b/packages/cli/__tests__/compile-stylex-folder-test.js
@@ -326,6 +326,7 @@ describe('cache mechanism works as expected', () => {
 });
 
 describe('CLI works with a custom cache path', () => {
+  let writeSpy;
   const customCachePath = path.join(__dirname, '__custom_cache__');
   const config: TransformConfig = {
     input: path.resolve('./source'),
@@ -346,14 +347,11 @@ describe('CLI works with a custom cache path', () => {
   config.cachePath = customCachePath;
 
   beforeEach(async () => {
-    if (
-      await fs
-        .access(customCachePath)
-        .then(() => true)
-        .catch(() => false)
-    ) {
-      await fs.rm(customCachePath, { recursive: true, force: true });
-    }
+    writeSpy2 = jest.spyOn(cacheModule, 'writeCache');
+  });
+
+  afterEach(() => {
+    writeSpy2.mockRestore();
   });
 
   afterAll(async () => {
@@ -396,6 +394,21 @@ describe('CLI works with a custom cache path', () => {
     expect(cacheData).toHaveProperty('outputHash');
     expect(cacheData).toHaveProperty('collectedCSS');
 
+  });
+  test('skips transformation when cache is valid', async () => {
+    await compileDirectory(config);
+
+    // Ensure no additional writes were made due to no file changes
+    expect(writeSpy2).toHaveBeenCalledTimes(0);
+    writeSpy2.mockRestore();
+
+    const customFilePath = path.join(config.input, 'index.js');
+
+    const cacheFilePath = path.join(
+      customCachePath,
+      path.relative(config.input, customFilePath) + '.json',
+    );
+
     await fs.rm(cacheFilePath, { recursive: true, force: true });
   });
 });
diff --git a/packages/cli/src/cache.js b/packages/cli/src/cache.js
index 2346a414..96544aa6 100644
--- a/packages/cli/src/cache.js
+++ b/packages/cli/src/cache.js
@@ -17,13 +17,13 @@ export function getDefaultCachePath() {
   return path.join('node_modules', '.stylex-cache');
 }
 
-async function getCacheFilePath(cachePath, filePath) {
+export async function getCacheFilePath(cachePath, filePath) {
   const fileName = filePath.replace(/[\\/]/g, '__');
   return path.join(cachePath, `${fileName}.json`);
 }
 
-export async function readCache(filePath) {
-  const cacheFile = await getCacheFilePath(getDefaultCachePath(), filePath);
+export async function readCache(cachePath, filePath) {
+  const cacheFile = await getCacheFilePath(cachePath, filePath);
   try {
     const cacheData = await fs.readFile(cacheFile, 'utf-8');
     return JSON.parse(cacheData);
diff --git a/packages/cli/src/transform.js b/packages/cli/src/transform.js
index 81757b98..8c957e65 100644
--- a/packages/cli/src/transform.js
+++ b/packages/cli/src/transform.js
@@ -108,7 +108,7 @@ export async function compileFile(
     oldOutputHash = await computeHash(outputFilePath);
   }
 
-  const cacheData = await readCache(filePath);
+  const cacheData = await readCache(cachePath, filePath);
 
   if (
     cacheData &&