Skip settings sync for repos that are already archived

When a repository is archived, GitHub treats it as read-only and rejects
any settings update (repository, branch protection, labels, teams, etc.)
with a 403 "Repository was archived so is read-only." error.

`updateRepos` only used the archive plugin's state to decide whether to
archive/unarchive a repo, but it still ran the repository plugin and all
child plugins unconditionally. For repos that are already archived and are
staying archived, this issues a `repos.update()` (and other writes) against
a read-only repo every sync, which 403s, gets logged as an error and
surfaces as a failing check run.

Skip the repository and child plugins when a repo is archived and is not
being unarchived in this run. Newly-archived repos (shouldArchive) are still
configured first and archived last, and repos being unarchived are configured
after the unarchive, so those paths are unchanged.

Add regression tests covering already-archived, newly-archived and
non-archived repos.

Author: pcrumley

lib/settings.js

@@ -370,23 +370,32 @@ ${this.results.reduce((x, y) => {
         const RepoPlugin = Settings.PLUGINS.repository
 
         const archivePlugin = new Archive(this.nop, this.github, repo, repoConfig, this.log)
-        const { shouldArchive, shouldUnarchive } = await archivePlugin.getState()
+        const { isArchived, shouldArchive, shouldUnarchive } = await archivePlugin.getState()
 
         if (shouldUnarchive) {
           this.log.debug(`Unarchiving repo ${repo.repo}`)
           const unArchiveResults = await archivePlugin.sync()
           this.appendToResults(unArchiveResults)
         }
 
-        const repoResults = await new RepoPlugin(this.nop, this.github, repo, repoConfig, this.installation_id, this.log, this.errors).sync()
-        this.appendToResults(repoResults)
+        // An archived repo is read-only: GitHub rejects any settings update
+        // (repository, branch protection, labels, teams, etc.) with a 403. If a
+        // repo is archived and is not being unarchived in this run, skip every
+        // other plugin and let only the archive plugin run. Newly-archived repos
+        // (shouldArchive) are still configured first and archived last, below.
+        if (isArchived && !shouldUnarchive) {
+          this.log.debug(`Skipping settings sync for archived repo ${repo.repo}`)
+        } else {
+          const repoResults = await new RepoPlugin(this.nop, this.github, repo, repoConfig, this.installation_id, this.log, this.errors).sync()
+          this.appendToResults(repoResults)
 
-        const childResults = await Promise.all(
-          childPlugins.map(([Plugin, config]) => {
-            return new Plugin(this.nop, this.github, repo, config, this.log, this.errors).sync()
-          })
-        )
-        this.appendToResults(childResults)
+          const childResults = await Promise.all(
+            childPlugins.map(([Plugin, config]) => {
+              return new Plugin(this.nop, this.github, repo, config, this.log, this.errors).sync()
+            })
+          )
+          this.appendToResults(childResults)
+        }
 
         if (shouldArchive) {
           this.log.debug(`Archiving repo ${repo.repo}`)

test/unit/lib/settings.test.js

@@ -462,4 +462,75 @@ repository:
       );
     });
   });
+
+  describe('updateRepos archived repos', () => {
+    const Archive = require('../../../lib/plugins/archive')
+    let settings
+
+    beforeEach(() => {
+      // suborg must be undefined, otherwise updateRepos returns early because the
+      // repo is not part of the changed suborg config.
+      mockSubOrg = undefined
+      stubConfig = {
+        restrictedRepos: {},
+        // Presence of a repository section means a repoConfig is built and the
+        // main `if (repoConfig)` branch of updateRepos runs.
+        repository: { has_wiki: false }
+      }
+      settings = createSettings(stubConfig)
+      // Avoid any network calls for config loading.
+      settings.subOrgConfigs = {}
+      settings.repoConfigs = {}
+      jest.spyOn(settings, 'childPluginsList').mockReturnValue([])
+    })
+
+    afterEach(() => {
+      jest.restoreAllMocks()
+    })
+
+    it('skips the repository plugin for a repo that is already archived', async () => {
+      jest.spyOn(Archive.prototype, 'getState').mockResolvedValue({
+        isArchived: true,
+        shouldArchive: false,
+        shouldUnarchive: false
+      })
+      const repoSync = jest.spyOn(Settings.PLUGINS.repository.prototype, 'sync').mockResolvedValue([])
+      const archiveSync = jest.spyOn(Archive.prototype, 'sync').mockResolvedValue([])
+
+      await settings.updateRepos({ owner: 'test', repo: 'archived-repo' })
+
+      // No settings update is attempted against the read-only archived repo.
+      expect(repoSync).not.toHaveBeenCalled()
+      expect(archiveSync).not.toHaveBeenCalled()
+    })
+
+    it('configures and then archives a repo that is being newly archived', async () => {
+      jest.spyOn(Archive.prototype, 'getState').mockResolvedValue({
+        isArchived: false,
+        shouldArchive: true,
+        shouldUnarchive: false
+      })
+      const repoSync = jest.spyOn(Settings.PLUGINS.repository.prototype, 'sync').mockResolvedValue([])
+      const archiveSync = jest.spyOn(Archive.prototype, 'sync').mockResolvedValue([])
+
+      await settings.updateRepos({ owner: 'test', repo: 'to-archive' })
+
+      // The repo is still writable, so settings are applied before it is archived.
+      expect(repoSync).toHaveBeenCalled()
+      expect(archiveSync).toHaveBeenCalled()
+    })
+
+    it('configures a non-archived repo as usual', async () => {
+      jest.spyOn(Archive.prototype, 'getState').mockResolvedValue({
+        isArchived: false,
+        shouldArchive: false,
+        shouldUnarchive: false
+      })
+      const repoSync = jest.spyOn(Settings.PLUGINS.repository.prototype, 'sync').mockResolvedValue([])
+
+      await settings.updateRepos({ owner: 'test', repo: 'normal-repo' })
+
+      expect(repoSync).toHaveBeenCalled()
+    })
+  }) // updateRepos archived repos
 }) // Settings Tests