feat: support @ and / when falling back to tags

src/github.ts

@@ -455,18 +455,9 @@ export class GitHub {
   // the branch we're configured for.
   async latestTag(
     prefix?: string,
-    preRelease = false,
-    // Allow a branch prefix to differ from a tag prefix. This was required
-    // for google-cloud-go, which uses the tag prefix library/vx.y.z.
-    // this is a requirement in the go community.
-    branchPrefix?: string
+    preRelease = false
   ): Promise<GitHubTag | undefined> {
-    const pull = await this.findMergedReleasePR(
-      [],
-      100,
-      branchPrefix ?? prefix,
-      preRelease
-    );
+    const pull = await this.findMergedReleasePR([], 100, prefix, preRelease);
     if (!pull) return await this.latestTagFallback(prefix, preRelease);
     const tag = {
       name: `v${pull.version}`,
@@ -514,6 +505,16 @@ export class GitHub {
   private async allTags(
     prefix?: string
   ): Promise<{[version: string]: GitHubTag}> {
+    // If we've fallen back to using allTags, support "-", "@", and "/" as a
+    // suffix separating the library name from the version #. This allows
+    // a repository to be seamlessly be migrated from a tool like lerna:
+    const prefixes: string[] = [];
+    if (prefix) {
+      prefix = prefix.substring(0, prefix.length - 1);
+      for (const suffix of ['-', '@', '/']) {
+        prefixes.push(`${prefix}${suffix}`);
+      }
+    }
     const tags: {[version: string]: GitHubTag} = {};
     for await (const response of this.octokit.paginate.iterator(
       this.decoratePaginateOpts({
@@ -526,8 +527,17 @@ export class GitHub {
       response.data.forEach((data: ReposListTagsResponseItems) => {
         // For monorepos, a prefix can be provided, indicating that only tags
         // matching the prefix should be returned:
-        if (prefix && !data.name.startsWith(prefix)) return;
-        let version = data.name.replace(prefix, '');
+        let version = data.name;
+        if (prefix) {
+          let match = false;
+          for (prefix of prefixes) {
+            if (data.name.startsWith(prefix)) {
+              version = data.name.replace(prefix, '');
+              match = true;
+            }
+          }
+          if (!match) return;
+        }
         if ((version = semver.valid(version))) {
           tags[version] = {sha: data.commit.sha, name: data.name, version};
         }

src/releasers/go-yoshi.ts

@@ -54,9 +54,8 @@ export class GoYoshi extends ReleasePR {
   static releaserName = 'go-yoshi';
   protected async _run(): Promise<number | undefined> {
     const latestTag = await this.gh.latestTag(
-      this.monorepoTags ? `${this.packageName}/` : undefined,
-      false,
-      this.monorepoTags ? `${this.packageName}` : undefined
+      this.monorepoTags ? `${this.packageName}-` : undefined,
+      false
     );
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
     const [_owner, repo] = parseGithubRepoUrl(this.repoUrl);

src/releasers/ruby.ts

@@ -41,9 +41,8 @@ export class Ruby extends ReleasePR {
   }
   protected async _run(): Promise<number | undefined> {
     const latestTag: GitHubTag | undefined = await this.gh.latestTag(
-      this.monorepoTags ? `${this.packageName}/` : undefined,
-      false,
-      this.monorepoTags ? `${this.packageName}-` : undefined
+      this.monorepoTags ? `${this.packageName}-` : undefined,
+      false
     );
     const commits: Commit[] = await this.commits({
       sha: latestTag ? latestTag.sha : undefined,

test/github.ts

@@ -332,6 +332,122 @@ describe('GitHub', () => {
       expect(latestTag!.version).to.equal('3.0.0-rc1');
       req.done();
     });
+    it('falls back to using tags, for simple case', async () => {
+      req
+        .get(
+          '/repos/fake/fake/pulls?state=closed&per_page=100&sort=merged_at&direction=desc'
+        )
+        .reply(200, [])
+        .get('/repos/fake/fake/tags?per_page=100')
+        .reply(200, [
+          {
+            name: 'v1.0.0',
+            commit: {sha: 'abc123'},
+          },
+          {
+            name: 'v1.1.0',
+            commit: {sha: 'deadbeef'},
+          },
+        ]);
+      const latestTag = await github.latestTag();
+      expect(latestTag!.version).to.equal('1.1.0');
+      req.done();
+    });
+    it('falls back to using tags, when prefix is provided', async () => {
+      req
+        .get(
+          '/repos/fake/fake/pulls?state=closed&per_page=100&sort=merged_at&direction=desc'
+        )
+        .reply(200, [])
+        .get('/repos/fake/fake/tags?per_page=100')
+        .reply(200, [
+          {
+            name: 'v1.0.0',
+            commit: {sha: 'abc123'},
+          },
+          {
+            name: 'v1.1.0',
+            commit: {sha: 'deadbeef'},
+          },
+          {
+            name: 'foo-v1.9.0',
+            commit: {sha: 'deadbeef'},
+          },
+          {
+            name: 'v1.2.0',
+            commit: {sha: 'deadbeef'},
+          },
+        ]);
+      const latestTag = await github.latestTag('foo-');
+      expect(latestTag!.version).to.equal('1.9.0');
+      req.done();
+    });
+    it('allows for "@" rather than "-" when fallback used', async () => {
+      req
+        .get(
+          '/repos/fake/fake/pulls?state=closed&per_page=100&sort=merged_at&direction=desc'
+        )
+        .reply(200, [])
+        .get('/repos/fake/fake/tags?per_page=100')
+        .reply(200, [
+          {
+            name: 'v1.0.0',
+            commit: {sha: 'abc123'},
+          },
+          {
+            name: 'v1.1.0',
+            commit: {sha: 'deadbeef'},
+          },
+          {
+            name: 'foo@v1.9.0',
+            commit: {sha: 'dead'},
+          },
+          {
+            name: 'v1.2.0',
+            commit: {sha: 'beef'},
+          },
+          {
+            name: 'foo@v2.1.0',
+            commit: {sha: '123abc'},
+          },
+        ]);
+      const latestTag = await github.latestTag('foo-');
+      expect(latestTag!.version).to.equal('2.1.0');
+      req.done();
+    });
+    it('allows for "/" rather than "-" when fallback used', async () => {
+      req
+        .get(
+          '/repos/fake/fake/pulls?state=closed&per_page=100&sort=merged_at&direction=desc'
+        )
+        .reply(200, [])
+        .get('/repos/fake/fake/tags?per_page=100')
+        .reply(200, [
+          {
+            name: 'v1.0.0',
+            commit: {sha: 'abc123'},
+          },
+          {
+            name: 'v1.1.0',
+            commit: {sha: 'deadbeef'},
+          },
+          {
+            name: 'foo/v2.3.0',
+            commit: {sha: 'dead'},
+          },
+          {
+            name: 'v1.2.0',
+            commit: {sha: 'beef'},
+          },
+          {
+            name: 'foo/v2.1.0',
+            commit: {sha: '123abc'},
+          },
+        ]);
+      const latestTag = await github.latestTag('foo-');
+      expect(latestTag!.version).to.equal('2.3.0');
+      req.done();
+    });
   });
 
   describe('getFileContents', () => {