perf: use git tag --merge <branch> to filter tags present in a branch history

BREAKING CHANGE: Git CLI version 2.7.1 or higher is now required

The `--merge` option of the `git tag` command has been added in Git version 2.7.1 and is now used by semantic-release

bin/semantic-release.js

@@ -10,7 +10,7 @@ var execa = require('execa');
 var findVersions = require('find-versions');
 var pkg = require('../package.json');
 
-var MIN_GIT_VERSION = '2.0.0';
+var MIN_GIT_VERSION = '2.7.1';
 
 if (!semver.satisfies(process.version, pkg.engines.node)) {
   console.error(

docs/support/FAQ.md

@@ -238,6 +238,10 @@ In addition the [verify conditions step](../../README.md#release-steps) verifies
 
 See [Node version requirement](./node-version.md#node-version-requirement) for more details and solutions.
 
+## Why does semantic-release require Git version >= 2.7.1?
+
+**semantic-release** uses Git CLI commands to read information about the repository such as branches, commit history and tags. Certain commands and options (such as [the `--merged` option of the `git tag` command](https://git-scm.com/docs/git-tag/2.7.0#git-tag---no-mergedltcommitgt) or bug fixes related to `git ls-files`) used by **semantic-release** are only available in Git version 2.7.1 and higher.
+
 ## What is npx?
 
 [`npx`](https://www.npmjs.com/package/npx) – short for "npm exec" – is a CLI to find and execute npm binaries within the local `node_modules` folder or in the $PATH. If a binary can't be located npx will download the required package and execute it from its cache location.

lib/branches/get-tags.js

@@ -2,7 +2,7 @@ const {template, escapeRegExp} = require('lodash');
 const semver = require('semver');
 const pReduce = require('p-reduce');
 const debug = require('debug')('semantic-release:get-tags');
-const {getTags, isRefInHistory, getTagHead} = require('../../lib/git');
+const {getTags, getTagHead} = require('../../lib/git');
 
 module.exports = async ({cwd, env, options: {tagFormat}}, branches) => {
   // Generate a regex to parse tags formatted with `tagFormat`
@@ -10,25 +10,18 @@ module.exports = async ({cwd, env, options: {tagFormat}}, branches) => {
   // The `tagFormat` is compiled with space as the `version` as it's an invalid tag character,
   // so it's guaranteed to no be present in the `tagFormat`.
   const tagRegexp = `^${escapeRegExp(template(tagFormat)({version: ' '})).replace(' ', '(.[^@]+)@?(.+)?')}`;
-  const tags = (await getTags({cwd, env}))
-    .map(tag => {
-      const [, version, channel] = tag.match(tagRegexp) || [];
-      return {gitTag: tag, version, channel};
-    })
-    .filter(({version}) => version && semver.valid(semver.clean(version)));
-
-  debug('found tags: %o', tags);
 
   return pReduce(
     branches,
     async (branches, branch) => {
-      const branchTags = await pReduce(
-        tags,
-        async (tags, {gitTag, ...rest}) =>
-          (await isRefInHistory(gitTag, branch.name, {cwd, env}))
-            ? [...tags, {...rest, gitTag, gitHead: await getTagHead(gitTag, {cwd, env})}]
-            : tags,
-        []
+      const branchTags = await Promise.all(
+        (await getTags(branch.name, {cwd, env}))
+          .map(tag => {
+            const [, version, channel] = tag.match(tagRegexp) || [];
+            return {gitTag: tag, version, channel};
+          })
+          .filter(({version}) => version && semver.valid(semver.clean(version)))
+          .map(async ({gitTag, ...rest}) => ({gitTag, gitHead: await getTagHead(gitTag, {cwd, env}), ...rest}))
       );
 
       debug('found tags for branch %s: %o', branch.name, branchTags);

lib/git.js

@@ -22,15 +22,16 @@ async function getTagHead(tagName, execaOpts) {
 }
 
 /**
- * Get all the repository tags.
+ * Get all the tags for a given branch.
  *
+ * @param {String} branch The branch for which to retrieve the tags.
  * @param {Object} [execaOpts] Options to pass to `execa`.
  *
  * @return {Array<String>} List of git tags.
  * @throws {Error} If the `git` command fails.
  */
-async function getTags(execaOpts) {
-  return (await execa('git', ['tag'], execaOpts)).stdout
+async function getTags(branch, execaOpts) {
+  return (await execa('git', ['tag', '--merged', branch], execaOpts)).stdout
     .split('\n')
     .map(tag => tag.trim())
     .filter(Boolean);

test/branches/get-tags.test.js

@@ -109,15 +109,15 @@ test('Return branches with and empty tags array if no valid tag is found', async
   await gitCommits(['Third'], {cwd});
   await gitTagVersion('v3.0', undefined, {cwd});
 
-  const result = await getTags({cwd, options: {tagFormat: `prefix@v\${version}`}}, [{name: 'master'}, {name: 'next'}]);
+  const result = await getTags({cwd, options: {tagFormat: `prefix@v\${version}`}}, [{name: 'master'}]);
 
-  t.deepEqual(result, [{name: 'master', tags: []}, {name: 'next', tags: []}]);
+  t.deepEqual(result, [{name: 'master', tags: []}]);
 });
 
 test('Return branches with and empty tags array if no valid tag is found in history of configured branches', async t => {
   const {cwd} = await gitRepo();
   await gitCommits(['First'], {cwd});
-  await gitCheckout('other-branch', true, {cwd});
+  await gitCheckout('next', true, {cwd});
   await gitCommits(['Second'], {cwd});
   await gitTagVersion('v1.0.0', undefined, {cwd});
   await gitTagVersion('v1.0.0@next', undefined, {cwd});

test/git.test.js

@@ -91,7 +91,7 @@ test('Fetch all tags on a detached head repository', async t => {
 
   await fetch(repositoryUrl, 'master', {cwd});
 
-  t.deepEqual((await getTags({cwd})).sort(), ['v1.0.0', 'v1.0.1', 'v1.1.0'].sort());
+  t.deepEqual((await getTags('master', {cwd})).sort(), ['v1.0.0', 'v1.0.1', 'v1.1.0'].sort());
 });
 
 test('Verify if the commit `sha` is in the direct history of the current branch', async t => {
@@ -243,7 +243,7 @@ test('Return falsy for invalid tag names', async t => {
 test('Throws error if obtaining the tags fails', async t => {
   const cwd = tempy.directory();
 
-  await t.throwsAsync(getTags({cwd}));
+  await t.throwsAsync(getTags('master', {cwd}));
 });
 
 test('Return "true" if repository is up to date', async t => {