TechDocs: Deduplicate git clone for cache check

Signed-off-by: Himanshu Mishra <himanshu@orkohunter.net>

packages/techdocs-common/src/helpers.ts

@@ -196,16 +196,9 @@ export const checkoutGitRepository = async (
 };
 
 export const getLastCommitTimestamp = async (
-  repositoryUrl: string,
-  config: Config,
+  repositoryLocation: string,
   logger: Logger,
 ): Promise<number> => {
-  const repositoryLocation = await checkoutGitRepository(
-    repositoryUrl,
-    config,
-    logger,
-  );
-
   const git = Git.fromAuth({ logger });
   const sha = await git.resolveRef({ dir: repositoryLocation, ref: 'HEAD' });
   const commit = await git.readCommit({ dir: repositoryLocation, sha });

packages/techdocs-common/src/stages/prepare/commonGit.test.ts

@@ -29,6 +29,7 @@ function normalizePath(path: string) {
 jest.mock('../../helpers', () => ({
   ...jest.requireActual<{}>('../../helpers'),
   checkoutGitRepository: jest.fn(() => '/tmp/backstage-repo/org/name/branch'),
+  getLastCommitTimestamp: jest.fn(() => 12345678),
 }));
 
 const createMockEntity = (annotations = {}) => {

packages/techdocs-common/src/stages/prepare/commonGit.ts

@@ -40,7 +40,7 @@ export class CommonGitPreparer implements PreparerBase {
     options?: { etag?: string },
   ): Promise<PreparerResponse> {
     this.logger.warn(
-      'You are using the legacy git preparer in TechDocs which will be removed in near future (30 days). ' +
+      'You are using the legacy git preparer in TechDocs which will be removed in near future (March 2021). ' +
         'Migrate to URL reader by updating `backstage.io/techdocs-ref` annotation in `catalog-info.yaml` ' +
         'to be prefixed with `url:`. Read the migration guide and benefits at https://github.com/backstage/backstage/issues/4409 ',
     );
@@ -57,13 +57,8 @@ export class CommonGitPreparer implements PreparerBase {
         this.config,
         this.logger,
       );
-
       // Check if etag has changed for cache invalidation.
-      const etag = await getLastCommitTimestamp(
-        target,
-        this.config,
-        this.logger,
-      );
+      const etag = await getLastCommitTimestamp(repoPath, this.logger);
       if (options?.etag === etag.toString()) {
         throw new NotModifiedError();
       }

packages/techdocs-common/src/stages/prepare/dir.ts

@@ -70,7 +70,7 @@ export class DirectoryPreparer implements PreparerBase {
 
   async prepare(entity: Entity): Promise<PreparerResponse> {
     this.logger.warn(
-      'You are using the legacy dir preparer in TechDocs which will be removed in near future (30 days). ' +
+      'You are using the legacy dir preparer in TechDocs which will be removed in near future (March 2021). ' +
         'Migrate to URL reader by updating `backstage.io/techdocs-ref` annotation in `catalog-info.yaml` ' +
         'to be prefixed with `url:`. Read the migration guide and benefits at https://github.com/backstage/backstage/issues/4409 ',
     );