allow cache-local-path w/o enable-cache (#707)

Fixes: #705

Author: eifinger

.github/workflows/test.yml

@@ -649,6 +649,26 @@ jobs:
           fi
         shell: bash
 
+  test-cache-local-cache-disabled-but-explicit-path:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - name: Setup without cache
+        uses: ./
+        with:
+          enable-cache: false
+          cache-local-path: /tmp/uv-cache-disabled
+
+      - name: Check UV_CACHE_DIR is set
+        run: |
+          if [ "$UV_CACHE_DIR" != "/tmp/uv-cache-disabled" ]; then
+            echo "UV_CACHE_DIR should be set when cache is disabled but explicit path is provided"
+            exit 1
+          fi
+        shell: bash
+
   test-setup-cache-local:
     runs-on: selfhosted-ubuntu-arm64
     steps:
@@ -984,6 +1004,7 @@ jobs:
       - test-musl
       - test-cache-local
       - test-cache-local-cache-disabled
+      - test-cache-local-cache-disabled-but-explicit-path
       - test-setup-cache
       - test-restore-cache
       - test-setup-cache-requirements-txt

dist/save-cache/index.js

@@ -134,6 +134,10 @@ It defaults to `setup-uv-cache` in the `TMP` dir, `D:\a\_temp\setup-uv-cache` on
 > If you configured [cache-dir](https://docs.astral.sh/uv/reference/settings/#cache-dir) in your
 > config file then it is also respected and this action will not set `UV_CACHE_DIR`.
 
+> [!NOTE]
+> If caching is disabled, you can still use `cache-local-path` so this action sets `UV_CACHE_DIR`
+> to your desired path.
+
 ```yaml
 - name: Define a custom uv cache path
   uses: astral-sh/setup-uv@v7

dist/setup/index.js

@@ -32,7 +32,12 @@ export async function restoreCache(): Promise<void> {
   core.info(
     `Trying to restore uv cache from GitHub Actions cache with key: ${cacheKey}`,
   );
-  const cachePaths = [cacheLocalPath];
+  if (cacheLocalPath === undefined) {
+    throw new Error(
+      "cache-local-path is not set. Cannot restore cache without a valid cache path.",
+    );
+  }
+  const cachePaths = [cacheLocalPath.path];
   if (cachePython) {
     cachePaths.push(pythonDir);
   }

docs/caching.md

@@ -59,10 +59,18 @@ async function saveCache(): Promise<void> {
     await pruneCache();
   }
 
-  let actualCachePath = cacheLocalPath;
-  if (process.env.UV_CACHE_DIR && process.env.UV_CACHE_DIR !== cacheLocalPath) {
+  if (cacheLocalPath === undefined) {
+    throw new Error(
+      "cache-local-path is not set. Cannot save cache without a valid cache path.",
+    );
+  }
+  let actualCachePath = cacheLocalPath.path;
+  if (
+    process.env.UV_CACHE_DIR &&
+    process.env.UV_CACHE_DIR !== cacheLocalPath.path
+  ) {
     core.warning(
-      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath}".`,
+      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath.path}".`,
     );
     actualCachePath = process.env.UV_CACHE_DIR;
   }

src/cache/restore-cache.ts

@@ -8,11 +8,11 @@ import {
   resolveVersion,
   tryGetFromToolCache,
 } from "./download/download-version";
-import { getConfigValueFromTomlFile } from "./utils/config-file";
 import { STATE_UV_PATH, STATE_UV_VERSION } from "./utils/constants";
 import {
   activateEnvironment as activateEnvironmentInput,
   addProblemMatchers,
+  CacheLocalSource,
   cacheLocalPath,
   checkSum,
   enableCache,
@@ -252,16 +252,15 @@ async function activateEnvironment(): Promise<void> {
 }
 
 function setCacheDir(): void {
-  if (enableCache) {
-    const cacheDirFromConfig = getConfigValueFromTomlFile("", "cache-dir");
-    if (cacheDirFromConfig !== undefined) {
+  if (cacheLocalPath !== undefined) {
+    if (cacheLocalPath.source === CacheLocalSource.Config) {
       core.info(
         "Using cache-dir from uv config file, not modifying UV_CACHE_DIR",
       );
       return;
     }
-    core.exportVariable("UV_CACHE_DIR", cacheLocalPath);
-    core.info(`Set UV_CACHE_DIR to ${cacheLocalPath}`);
+    core.exportVariable("UV_CACHE_DIR", cacheLocalPath.path);
+    core.info(`Set UV_CACHE_DIR to ${cacheLocalPath.path}`);
   }
 }