Check for wrong venv path in cache (#287)

Commit c5f9dab overwrote the venv_path if it didn't match. Tests showed that some packages like certifi still relied on the hardcoded old path. Moreover it is not supported by rye to move venvs between paths and this action now complies with that rather than trying to be overly smart. The impact is a cache miss.

.github/workflows/test-cache.yml

@@ -20,7 +20,6 @@ jobs:
       - name: Setup with cache
         uses: ./
         with:
-          version: '0.11.0'
           enable-cache: true
           working-directory: __tests__/fixtures/rye-project
           cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}
@@ -38,7 +37,6 @@ jobs:
         id: restore
         uses: ./
         with:
-            version: '0.11.0'
             enable-cache: true
             working-directory: __tests__/fixtures/rye-project
             cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}
@@ -65,16 +63,52 @@ jobs:
           cache-local-storage-path: /tmp/rye-cache
       - run: rye sync
         working-directory: __tests__/fixtures/rye-project
+  test-restore-cache-local:
+    runs-on: oracle-aarch64
+    needs: test-setup-cache-local
+    steps:
+      - uses: actions/checkout@v4
+      - name: Restore with cache
+        id: restore
+        uses: ./
+        with:
+            enable-cache: true
+            working-directory: __tests__/fixtures/rye-project
+            cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}
+            cache-local-storage-path: /tmp/rye-cache
+      - name: Cache was hit
+        run: |
+          if [ "$CACHE_HIT" != "true" ]; then
+            exit 1
+          fi
+        env:
+          CACHE_HIT: ${{ steps.restore.outputs.cache-hit }}
+      - run: rye sync
+        working-directory: __tests__/fixtures/rye-project
+
+  test-setup-cache-local-venv-path-mismatch:
+    runs-on: oracle-aarch64
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup with cache
+        uses: ./
+        with:
+          enable-cache: true
+          working-directory: __tests__/fixtures/rye-project
+          cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}-path-mismatch
+          cache-local-storage-path: /tmp/rye-cache
+      - run: rye sync
+        working-directory: __tests__/fixtures/rye-project
   alter-venv-path-in-cache-local:
     runs-on: oracle-aarch64
     needs: test-setup-cache-local
     steps:
       - uses: actions/checkout@v4
       - name: Alter venv path in cache
         run: |
-          RYE_VENV_PATH=$(find /tmp/rye-cache -type f -name 'rye-venv.json' -path '/tmp/rye-cache/${{ github.run_id }}-${{ github.run_attempt }}*')
+          RYE_VENV_PATH=$(find /tmp/rye-cache -type f -name 'rye-venv.json' -path '/tmp/rye-cache/${{ github.run_id }}-${{ github.run_attempt }}-path-mismatch*')
           sed -i 's/"venv_path":\s*"[^"]*"/"venv_path": "something"/' "$RYE_VENV_PATH"
-  test-restore-cache-local:
+  test-restore-cache-local-venv-path-mismatch:
     runs-on: oracle-aarch64
     needs: alter-venv-path-in-cache-local
     steps:
@@ -85,14 +119,14 @@ jobs:
         with:
             enable-cache: true
             working-directory: __tests__/fixtures/rye-project
-            cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}
+            cache-prefix: ${{ github.run_id }}-${{ github.run_attempt }}-path-mismatch
             cache-local-storage-path: /tmp/rye-cache
-      - name: Cache was hit
+      - name: Cache was not hit
         run: |
-          if [ "$CACHE_HIT" != "true" ]; then
+          if [ "$CACHE_HIT" == "true" ]; then
             exit 1
           fi
         env:
           CACHE_HIT: ${{ steps.restore.outputs.cache-hit }}
       - run: rye sync
-        working-directory: __tests__/fixtures/rye-project
+        working-directory: __tests__/fixtures/rye-project

src/restore-cache.ts

@@ -62,34 +62,41 @@ function handleMatchResult(
   matchedKey: string | undefined,
   primaryKey: string
 ): void {
-  if (matchedKey) {
-    core.saveState(STATE_CACHE_MATCHED_KEY, matchedKey)
-    core.info(
-      `.venv restored from${cacheLocalStoragePath ? ' local' : ''} cache with key: ${matchedKey}`
-    )
-    overwriteCachedVenvPath()
-    core.setOutput('cache-hit', true)
-  } else {
+  if (!matchedKey) {
     core.info(
       `No${cacheLocalStoragePath ? ' local' : ''} cache found for key: ${primaryKey}`
     )
     core.setOutput('cache-hit', false)
+    return
+  }
+
+  const venvPathMatch = doesCachedVenvPathMatchCurrentVenvPath()
+  if (!venvPathMatch) {
+    fs.rmSync(venvPath, {recursive: true})
+    core.setOutput('cache-hit', false)
+    return
   }
+
+  core.saveState(STATE_CACHE_MATCHED_KEY, matchedKey)
+  core.info(
+    `.venv restored from${cacheLocalStoragePath ? ' local' : ''} cache with key: ${matchedKey}`
+  )
+  core.setOutput('cache-hit', true)
 }
 
-/**
- * Overwrite the cached venv path in rye-venv.json
- *
- * Rye prevents unwanted behavior if people copy around .venv between projects.
- * But we can be sure, that we are always working with the same project but the base path of previous runners might be different.
- */
-function overwriteCachedVenvPath(): void {
+function doesCachedVenvPathMatchCurrentVenvPath(): boolean {
   const ryeVenvPath = `${venvPath}/rye-venv.json`
-  let ryeVenv = JSON.parse(fs.readFileSync(ryeVenvPath, 'utf8'))
-  core.debug(`venv_path in cache: ${ryeVenv.venv_path}`)
-  core.debug(`Overwriting cached venv_path with ${venvPath}`)
-  ryeVenv.venv_path = venvPath
-  fs.writeFileSync(ryeVenvPath, JSON.stringify(ryeVenv))
+  const ryeVenv = JSON.parse(fs.readFileSync(ryeVenvPath, 'utf8'))
+  core.info(
+    `Checking if the cached .venv matches the current path: ${venvPath}`
+  )
+  if (ryeVenv.venv_path != venvPath) {
+    core.warning(
+      `The .venv in the cache cannot be used because it is from another location: ${ryeVenv.venv_path}`
+    )
+    return false
+  }
+  return true
 }
 
 async function restoreCacheLocal(