From cbe3ec3ea18a8adf9ef339c33ff89b256471a9e3 Mon Sep 17 00:00:00 2001
From: Pelle Wessman <pelle@kodfabrik.se>
Date: Mon, 27 Feb 2023 19:27:47 +0100
Subject: [PATCH] Simplifies cache fallback + add timed invalidation

---
 README.md                       |  2 ++
 __tests__/cache-restore.test.ts | 10 +++++-----
 action.yml                      |  2 ++
 src/cache-restore.ts            | 13 ++++++++++---
 src/main.ts                     |  3 ++-
 5 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index ba67317c9..ba7dfbf1f 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,8 @@ The action defaults to search for the dependency file (`package-lock.json`, `npm
 
 **Note:** The action does not cache `node_modules`
 
+Use `cache-invalidate-after-days` to change the default fallback cache invalidation of every 120 days. Set to 0 to deactivate.
+
 See the examples of using cache for `yarn`/`pnpm` and `cache-dependency-path` input in the [Advanced usage](docs/advanced-usage.md#caching-packages-data) guide.
 
 **Caching npm dependencies:**
diff --git a/__tests__/cache-restore.test.ts b/__tests__/cache-restore.test.ts
index cd9cde55a..68de2af6d 100644
--- a/__tests__/cache-restore.test.ts
+++ b/__tests__/cache-restore.test.ts
@@ -132,13 +132,13 @@ describe('cache-restore', () => {
           }
         });
 
-        await restoreCache(packageManager);
+        await restoreCache(packageManager, undefined, '0');
         expect(hashFilesSpy).toHaveBeenCalled();
         expect(infoSpy).toHaveBeenCalledWith(
-          `Cache restored from key: ${platform}-setup-node-${packageManager}-${fileHash}`
+          `Cache restored from key: ${platform}-0-setup-node-${packageManager}-${fileHash}`
         );
         expect(infoSpy).not.toHaveBeenCalledWith(
-          `Cache not found for input keys: ${platform}-setup-node-${packageManager}-${fileHash}, ${platform}-setup-node-${packageManager}-, ${platform}-setup-node-`
+          `Cache not found for input keys: ${platform}-0-setup-node-${packageManager}-${fileHash}, ${platform}-0-setup-node-${packageManager}-`
         );
         expect(setOutputSpy).toHaveBeenCalledWith('cache-hit', true);
       }
@@ -163,10 +163,10 @@ describe('cache-restore', () => {
         });
 
         restoreCacheSpy.mockImplementationOnce(() => undefined);
-        await restoreCache(packageManager);
+        await restoreCache(packageManager, undefined, '0');
         expect(hashFilesSpy).toHaveBeenCalled();
         expect(infoSpy).toHaveBeenCalledWith(
-          `Cache not found for input keys: ${platform}-setup-node-${packageManager}-${fileHash}, ${platform}-setup-node-${packageManager}-, ${platform}-setup-node-`
+          `Cache not found for input keys: ${platform}-0-setup-node-${packageManager}-${fileHash}, ${platform}-0-setup-node-${packageManager}-`
         );
         expect(setOutputSpy).toHaveBeenCalledWith('cache-hit', false);
       }
diff --git a/action.yml b/action.yml
index b22de1ef6..13473abfa 100644
--- a/action.yml
+++ b/action.yml
@@ -25,6 +25,8 @@ inputs:
     description: 'Used to specify a package manager for caching in the default directory. Supported values: npm, yarn, pnpm.'
   cache-dependency-path:
     description: 'Used to specify the path to a dependency file: package-lock.json, yarn.lock, etc. Supports wildcards or a list of file names for caching multiple dependencies.'
+  cache-invalidate-after-days:
+    description: 'Used to control how often the fallback cache is invalidated automatically.'
 # TODO: add input to control forcing to pull from cloud or dist. 
 #       escape valve for someone having issues or needing the absolute latest which isn't cached yet
 outputs:
diff --git a/src/cache-restore.ts b/src/cache-restore.ts
index cb81844c5..d72da4ed8 100644
--- a/src/cache-restore.ts
+++ b/src/cache-restore.ts
@@ -13,7 +13,8 @@ import {
 
 export const restoreCache = async (
   packageManager: string,
-  cacheDependencyPath?: string
+  cacheDependencyPath?: string,
+  cacheInvalidateAfterDays?: string
 ) => {
   const packageManagerInfo = await getPackageManagerInfo(packageManager);
   if (!packageManagerInfo) {
@@ -35,9 +36,15 @@ export const restoreCache = async (
       'Some specified paths were not resolved, unable to cache dependencies.'
     );
   }
-  const keyPrefix = `${platform}-setup-node-`;
+  const numericCacheInvalidateAfterDays = cacheInvalidateAfterDays && cacheInvalidateAfterDays === '0'
+    ? 0
+    : (parseInt(cacheInvalidateAfterDays || '', 10) || 120)
+  const timedInvalidationPrefix = numericCacheInvalidateAfterDays
+    ? Math.floor(Date.now() / (1000 * 60 * 60 * 24 * numericCacheInvalidateAfterDays)) % 1000 // % 1000 to get a rolling prefix between 0 and 999 rather than a possibly infinitely large
+    : 0;
+  const keyPrefix = `${platform}-${timedInvalidationPrefix}-setup-node-`;
   const primaryKey = `${keyPrefix}${packageManager}-${fileHash}`;
-  const restoreKeys = [`${keyPrefix}${packageManager}-`, keyPrefix];
+  const restoreKeys = [`${keyPrefix}${packageManager}-`];
   core.debug(`primary key is ${primaryKey}`);
   core.saveState(State.CachePrimaryKey, primaryKey);
 
diff --git a/src/main.ts b/src/main.ts
index 90cd1d9d9..7708a606d 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -61,7 +61,8 @@ export async function run() {
 
     if (cache && isCacheFeatureAvailable()) {
       const cacheDependencyPath = core.getInput('cache-dependency-path');
-      await restoreCache(cache, cacheDependencyPath);
+      const cacheInvalidateAfterDays = core.getInput('cache-invalidate-after-days');
+      await restoreCache(cache, cacheDependencyPath, cacheInvalidateAfterDays);
     }
 
     const matchersPath = path.join(__dirname, '../..', '.github');