fix(onboarding): add commitBody to commitMessage

lib/config/types.ts

@@ -208,6 +208,7 @@ export interface RenovateConfig
     Record<string, unknown> {
   depName?: string;
   baseBranches?: string[];
+  commitBody?: string;
   useBaseBranchConfig?: UseBaseBranchConfigType;
   baseBranch?: string;
   defaultBranch?: string;

lib/workers/repository/onboarding/branch/create.spec.ts

@@ -57,6 +57,54 @@ describe('workers/repository/onboarding/branch/create', () => {
       });
     });
 
+    describe('applies the commitBody value', () => {
+      it('to the default commit message', async () => {
+        await createOnboardingBranch({
+          ...config,
+          commitBody: 'some commit body',
+        });
+        expect(scm.commitAndPush).toHaveBeenCalledWith({
+          branchName: 'renovate/configure',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: '{"foo":"bar"}',
+            },
+          ],
+          force: true,
+          message: `Add renovate.json\n\nsome commit body`,
+          platformCommit: false,
+        });
+      });
+
+      it('to the supplied commit message', async () => {
+        const message =
+          'We can Renovate if we want to, we can leave PRs in decline';
+
+        config.onboardingCommitMessage = message;
+
+        await createOnboardingBranch({
+          ...config,
+          commitBody: 'Signed Off: {{{gitAuthor}}}',
+          gitAuthor: '<Bot bot@botland.com>',
+        });
+        expect(scm.commitAndPush).toHaveBeenCalledWith({
+          branchName: 'renovate/configure',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: '{"foo":"bar"}',
+            },
+          ],
+          force: true,
+          message: `We can Renovate if we want to, we can leave PRs in decline\n\nSigned Off: <Bot bot@botland.com>`,
+          platformCommit: false,
+        });
+      });
+    });
+
     describe('applies the commitMessagePrefix value', () => {
       it('to the default commit message', async () => {
         const prefix = 'RENOV-123';

lib/workers/repository/onboarding/branch/create.ts

@@ -3,6 +3,7 @@ import { GlobalConfig } from '../../../../config/global';
 import type { RenovateConfig } from '../../../../config/types';
 import { logger } from '../../../../logger';
 import { scm } from '../../../../modules/platform/scm';
+import { compile } from '../../../../util/template';
 import { OnboardingCommitMessageFactory } from './commit-message';
 import { getOnboardingConfigContents } from './config';
 
@@ -25,7 +26,17 @@ export async function createOnboardingBranch(
     config,
     configFile!,
   );
-  const commitMessage = commitMessageFactory.create();
+  let commitMessage = commitMessageFactory.create().toString();
+
+  if (config.commitBody) {
+    commitMessage = `${commitMessage}\n\n${compile(
+      config.commitBody,
+      // only allow gitAuthor template value in the commitBody
+      { gitAuthor: config.gitAuthor },
+    )}`;
+
+    logger.trace(`commitMessage: ${commitMessage}`);
+  }
 
   // istanbul ignore if
   if (GlobalConfig.get('dryRun')) {
@@ -44,7 +55,7 @@ export async function createOnboardingBranch(
         contents,
       },
     ],
-    message: commitMessage.toString(),
+    message: commitMessage,
     platformCommit: !!config.platformCommit,
     force: true,
   });