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/wizard/cli.ts

@@ -0,0 +1,54 @@
+/**
+ * @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 {CommitMsgSource} from '../commit-message-source';
+
+import {runWizard} from './wizard';
+
+
+export interface WizardOptions {
+  filePath: string;
+  commitSha: string|undefined;
+  source: CommitMsgSource|undefined;
+}
+
+/** Builds the command. */
+function builder(yargs: Argv) {
+  return yargs
+      .positional('filePath', {
+        description: 'The file path to write the generated commit message into',
+        type: 'string',
+        demandOption: true,
+      })
+      .positional('source', {
+        choices: ['message', 'template', 'merge', 'squash', 'commit'] as const,
+        description: 'The source of the commit message as described here: ' +
+            'https://git-scm.com/docs/githooks#_prepare_commit_msg'
+      })
+      .positional('commitSha', {
+        description: 'The commit sha if source is set to `commit`',
+        type: 'string',
+      });
+}
+
+/** Handles the command. */
+async function handler(args: Arguments<WizardOptions>) {
+  await runWizard(args);
+}
+
+/** yargs command module describing the command.  */
+export const WizardModule: CommandModule<{}, WizardOptions> = {
+  handler,
+  builder,
+  command: 'wizard <filePath> [source] [commitSha]',
+  // Description: Run the wizard to build a base commit message before opening to complete.
+  // No describe is defiend to hide the command from the --help.
+  describe: false,
+};

dev-infra/commit-message/wizard/wizard.ts

@@ -0,0 +1,45 @@
+/**
+ * @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 {writeFileSync} from 'fs';
+
+import {getUserConfig} from '../../utils/config';
+import {debug, info} from '../../utils/console';
+
+import {buildCommitMessage} from '../builder';
+import {CommitMsgSource} from '../commit-message-source';
+
+
+/** The default commit message used if the wizard does not procude a commit message. */
+const defaultCommitMessage = `<type>(<scope>): <summary>
+
+# <Describe the motivation behind this change - explain WHY you are making this change. Wrap all
+#  lines at 100 characters.>\n\n`;
+
+export async function runWizard(
+    args: {filePath: string, source?: CommitMsgSource, commitSha?: string}) {
+  if (getUserConfig().commitMessage?.disableWizard) {
+    debug('Skipping commit message wizard due to enabled `commitMessage.disableWizard` option in');
+    debug('user config.');
+    process.exitCode = 0;
+    return;
+  }
+
+  if (args.source !== undefined) {
+    info(`Skipping commit message wizard because the commit was created via '${
+        args.source}' source`);
+    process.exitCode = 0;
+    return;
+  }
+
+  // Set the default commit message to be updated if the user cancels out of the wizard in progress
+  writeFileSync(args.filePath, defaultCommitMessage);
+
+  /** The generated commit message. */
+  const commitMessage = await buildCommitMessage();
+  writeFileSync(args.filePath, commitMessage);
+}