refactor(dev-infra): refactor commit-message files (#38845)

Refactor the commit-message files to be consistent with how other ng-dev tooling
is structured.

PR Close #38845

dev-infra/commit-message/validate-range/cli.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Arguments, Argv, CommandModule} from 'yargs';
+
+import {info} from '../../utils/console';
+
+import {validateCommitRange} from './validate-range';
+
+
+export interface ValidateRangeOptions {
+  range: string;
+}
+
+/** Builds the command. */
+function builder(yargs: Argv) {
+  return yargs.option('range', {
+    description: 'The range of commits to check, e.g. --range abc123..xyz456',
+    demandOption: '  A range must be provided, e.g. --range abc123..xyz456',
+    type: 'string',
+    requiresArg: true,
+  });
+}
+
+/** Handles the command. */
+async function handler({range}: Arguments<ValidateRangeOptions>) {
+  // If on CI, and no pull request number is provided, assume the branch
+  // being run on is an upstream branch.
+  if (process.env['CI'] && process.env['CI_PULL_REQUEST'] === 'false') {
+    info(`Since valid commit messages are enforced by PR linting on CI, we do not`);
+    info(`need to validate commit messages on CI runs on upstream branches.`);
+    info();
+    info(`Skipping check of provided commit range`);
+    return;
+  }
+  validateCommitRange(range);
+}
+
+/** yargs command module describing the command.  */
+export const ValidateRangeModule: CommandModule<{}, ValidateRangeOptions> = {
+  handler,
+  builder,
+  command: 'validate-range',
+  describe: 'Validate a range of commit messages',
+};

dev-infra/commit-message/validate-range/validate-range.ts

@@ -0,0 +1,77 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {error, info} from '../../utils/console';
+import {exec} from '../../utils/shelljs';
+
+import {parseCommitMessage} from '../parse';
+import {printValidationErrors, validateCommitMessage, ValidateCommitMessageOptions} from '../validate';
+
+// Whether the provided commit is a fixup commit.
+const isNonFixup = (m: string) => !parseCommitMessage(m).isFixup;
+
+// Extracts commit header (first line of commit message).
+const extractCommitHeader = (m: string) => parseCommitMessage(m).header;
+
+/** Validate all commits in a provided git commit range. */
+export function validateCommitRange(range: string) {
+  /**
+   * A random value is used as a string to allow for a definite split point in the git log result.
+   */
+  const randomValueSeparator = `${Math.random()}`;
+  /**
+   * Custom git log format that provides the commit header and body, separated as expected with the
+   * custom separator as the trailing value.
+   */
+  const gitLogFormat = `%s%n%n%b${randomValueSeparator}`;
+  /**
+   * A list of tuples containing a commit header string and the list of error messages for the
+   * commit.
+   */
+  const errors: [commitHeader: string, errors: string[]][] = [];
+
+  // Retrieve the commits in the provided range.
+  const result = exec(`git log --reverse --format=${gitLogFormat} ${range}`);
+  if (result.code) {
+    throw new Error(`Failed to get all commits in the range: \n  ${result.stderr}`);
+  }
+
+  // Separate the commits from a single string into individual commits
+  const commits = result.split(randomValueSeparator).map(l => l.trim()).filter(line => !!line);
+
+  info(`Examining ${commits.length} commit(s) in the provided range: ${range}`);
+
+  // Check each commit in the commit range.  Commits are allowed to be fixup commits for other
+  // commits in the provided commit range.
+  const allCommitsInRangeValid = commits.every((m, i) => {
+    const options: ValidateCommitMessageOptions = {
+      disallowSquash: true,
+      nonFixupCommitHeaders: isNonFixup(m) ?
+          undefined :
+          commits.slice(0, i).filter(isNonFixup).map(extractCommitHeader)
+    };
+    const {valid, errors: localErrors, commit} = validateCommitMessage(m, options);
+    if (localErrors.length) {
+      errors.push([commit.header, localErrors]);
+    }
+    return valid;
+  });
+
+  if (allCommitsInRangeValid) {
+    info('√  All commit messages in range valid.');
+  } else {
+    error('✘  Invalid commit message');
+    errors.forEach(([header, validationErrors]) => {
+      error.group(header);
+      printValidationErrors(validationErrors);
+      error.groupEnd();
+    });
+    // Exit with a non-zero exit code if invalid commit messages have
+    // been discovered.
+    process.exit(1);
+  }
+}