fix: drop cache for new majors (#1419)

currently when new majors are introduced we need to shift around
branches / older versions need to be rebuild, so we invalidate the cache
here when a new major is introduced

cli/lib/build.js

@@ -113,6 +113,12 @@ const main = async ({loglevel, releases: rawReleases, useCurrent, navPath, conte
     }
   })
 
+  /**
+   * this voids the cache when a new version is added to release.json / not in the cli-cache.json
+   * this is done so that the previous major versions nav can be reset to legacy and pages can be droped from its variant
+   */
+  cache?.voidOnNewKey(releases.map(v => v.id))
+
   const updates = await Promise.all(
     releases.map(r => extractRelease(r, {cache, contentPath, baseNav: navData, prerelease})),
   ).then(r => r.filter(Boolean))

cli/lib/cache.js

@@ -2,6 +2,8 @@ const fs = require('fs/promises')
 
 /** cache npm cli version shas to NOT pull down changes we already have */
 class CacheVersionSha {
+  shouldVoid = false
+
   constructor(cache, path) {
     this.cache = cache
     this.path = path
@@ -11,6 +13,16 @@ class CacheVersionSha {
     return new CacheVersionSha(JSON.parse(await fs.readFile(path, 'utf-8')), path)
   }
 
+  get keys() {
+    return Object.keys(this.cache)
+  }
+
+  voidOnNewKey(keys) {
+    if (keys.length !== this.keys.length || !keys.every(key => this.keys.includes(key))) {
+      this.shouldVoid = true
+    }
+  }
+
   async save() {
     const sortedCache = {}
     Object.keys(this.cache)
@@ -33,6 +45,7 @@ class CacheVersionSha {
   }
 
   same(id, value) {
+    if (this.shouldVoid) return false
     return this.cache[id] === value
   }
 }