feat(dev-infra): add utility method to GitClient to get latest SemVer tag (#41455)

Create a utility method for the latest git tag, sorted by committerdate, which
matches SemVer, representing the latest version released on the branch.

PR Close #41455

dev-infra/ng-dev.js

@@ -12,11 +12,11 @@ var path = require('path');
 var shelljs = require('shelljs');
 var url = require('url');
 var child_process = require('child_process');
+var semver = require('semver');
 var graphql = require('@octokit/graphql');
 var Octokit = require('@octokit/rest');
 var typedGraphqlify = require('typed-graphqlify');
 var fetch = _interopDefault(require('node-fetch'));
-var semver = require('semver');
 var multimatch = require('multimatch');
 var yaml = require('yaml');
 var conventionalCommitsParser = require('conventional-commits-parser');
@@ -704,6 +704,16 @@ var GitClient = /** @class */ (function () {
         }
         return this.runGraceful(['checkout', branchOrRevision], { stdio: 'ignore' }).status === 0;
     };
+    /** Gets the latest git tag on the current branch that matches SemVer. */
+    GitClient.prototype.getLatestSemverTag = function () {
+        var semVerOptions = { loose: true };
+        var tags = this.runGraceful(['tag', '--sort=-committerdate', '--merged']).stdout.split('\n');
+        var latestTag = tags.find(function (tag) { return semver.parse(tag, semVerOptions); });
+        if (latestTag === undefined) {
+            throw new Error("Unable to find a SemVer matching tag on \"" + this.getCurrentBranchOrRevision() + "\"");
+        }
+        return new semver.SemVer(latestTag, semVerOptions);
+    };
     /**
      * Assert the GitClient instance is using a token with permissions for the all of the
      * provided OAuth scopes.

dev-infra/utils/BUILD.bazel

@@ -17,10 +17,12 @@ ts_library(
         "@npm//@octokit/types",
         "@npm//@types/inquirer",
         "@npm//@types/node",
+        "@npm//@types/semver",
         "@npm//@types/shelljs",
         "@npm//@types/yargs",
         "@npm//chalk",
         "@npm//inquirer",
+        "@npm//semver",
         "@npm//shelljs",
         "@npm//tslib",
         "@npm//typed-graphqlify",

dev-infra/utils/git/index.ts

@@ -8,6 +8,7 @@
 
 import * as Octokit from '@octokit/rest';
 import {spawnSync, SpawnSyncOptions, SpawnSyncReturns} from 'child_process';
+import {Options as SemVerOptions, parse, SemVer} from 'semver';
 
 import {getConfig, getRepoBaseDir, NgDevConfig} from '../config';
 import {debug, info, yellow} from '../console';
@@ -181,6 +182,19 @@ export class GitClient {
     return this.runGraceful(['checkout', branchOrRevision], {stdio: 'ignore'}).status === 0;
   }
 
+  /** Gets the latest git tag on the current branch that matches SemVer. */
+  getLatestSemverTag(): SemVer {
+    const semVerOptions: SemVerOptions = {loose: true};
+    const tags = this.runGraceful(['tag', '--sort=-committerdate', '--merged']).stdout.split('\n');
+    const latestTag = tags.find((tag: string) => parse(tag, semVerOptions));
+
+    if (latestTag === undefined) {
+      throw new Error(
+          `Unable to find a SemVer matching tag on "${this.getCurrentBranchOrRevision()}"`);
+    }
+    return new SemVer(latestTag, semVerOptions);
+  }
+
   /**
    * Assert the GitClient instance is using a token with permissions for the all of the
    * provided OAuth scopes.