feat: add option to disable cache pruning (#134)

This PR adds an input to control whether or not the cache is pruned
before saving.

Closes #122

---------

Co-authored-by: Kevin Stillhammer <[email protected]>
Co-authored-by: Charlie Marsh <[email protected]>
Co-authored-by: Charlie Marsh <[email protected]>

Author: 3 people

README.md

@@ -166,6 +166,26 @@ It defaults to `setup-uv-cache` in the `TMP` dir, `D:\a\_temp\uv-tool-dir` on Wi
     cache-local-path: "/path/to/cache"
 ```
 
+### Disable cache pruning
+
+By default, the uv cache is pruned after every run, removing pre-built wheels, but retaining any
+wheels that were built from source. On GitHub-hosted runners, it's typically faster to omit those
+pre-built wheels from the cache (and instead re-download them from the registry on each run).
+However, on self-hosted or local runners, preserving the cache may be more efficient. See
+the[documentation](https://docs.astral.sh/uv/concepts/cache/#caching-in-continuous-integration) for
+more.
+
+If you want to persist the entire cache across runs, disable cache pruning with the `prune-cache`
+input.
+
+```yaml
+- name: Don't prune the cache before saving it
+  uses: astral-sh/setup-uv@v3
+  with:
+    enable-cache: true
+    prune-cache: false
+```
+
 ### GitHub authentication token
 
 This action uses the GitHub API to fetch the uv release artifacts. To avoid hitting the GitHub API

action.yml

@@ -29,6 +29,9 @@ inputs:
   cache-local-path:
     description: "Local path to store the cache."
     default: ""
+  prune-cache:
+    description: "Prune cache before saving."
+    default: true
   tool-dir:
     description: "Custom path to set UV_TOOL_DIR to."
     required: false

dist/save-cache/index.js

@@ -5,7 +5,11 @@ import {
   STATE_CACHE_MATCHED_KEY,
   STATE_CACHE_KEY,
 } from "./cache/restore-cache";
-import { cacheLocalPath, enableCache } from "./utils/inputs";
+import {
+  cacheLocalPath,
+  enableCache,
+  pruneCache as shouldPruneCache,
+} from "./utils/inputs";
 
 export async function run(): Promise<void> {
   try {
@@ -32,7 +36,9 @@ async function saveCache(): Promise<void> {
     return;
   }
 
-  await pruneCache();
+  if (shouldPruneCache) {
+    await pruneCache();
+  }
 
   core.info(`Saving cache path: ${cacheLocalPath}`);
   await cache.saveCache([cacheLocalPath], cacheKey);

dist/setup/index.js

@@ -7,6 +7,7 @@ export const enableCache = core.getInput("enable-cache") === "true";
 export const cacheSuffix = core.getInput("cache-suffix") || "";
 export const cacheLocalPath = getCacheLocalPath();
 export const cacheDependencyGlob = core.getInput("cache-dependency-glob");
+export const pruneCache = core.getInput("prune-cache") === "true";
 export const toolBinDir = getToolBinDir();
 export const toolDir = getToolDir();
 export const githubToken = core.getInput("github-token");