From d93ab869ca2779e4c2090725309bb49d18286b25 Mon Sep 17 00:00:00 2001
From: Eric Zimanyi <ezimanyi@gmail.com>
Date: Sat, 7 May 2022 14:11:31 -0400
Subject: [PATCH] Expire cache periodically to avoid unbounded size

The cache key includes a sequence number that rotates every 7 days
but because we are also using the base `golangci-lint.cache` as a
restore key, the new cache will always be seeded with the full
contents of the old cache.

In particular for the go module cache, this leads to an ever
increasing number of cached packages that never get pruned.

This commit updates it so we stop using `golangci-lint.cache` as
a restore key, which will force a build from an empty cache once
every 7 days.
---
 src/cache.ts | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/cache.ts b/src/cache.ts
index c29f295..a06f33f 100644
--- a/src/cache.ts
+++ b/src/cache.ts
@@ -52,12 +52,9 @@ const getIntervalKey = (invalidationIntervalDays: number): string => {
 
 async function buildCacheKeys(): Promise<string[]> {
   const keys = []
-  let cacheKey = `golangci-lint.cache-`
-  keys.push(cacheKey)
-
   // Periodically invalidate a cache because a new code being added.
   // TODO: configure it via inputs.
-  cacheKey += `${getIntervalKey(7)}-`
+  let cacheKey = `golangci-lint.cache-${getIntervalKey(7)}-`
   keys.push(cacheKey)
 
   if (await pathExists(`go.mod`)) {