feat(config/migration): migrate config with a PR

docs/usage/configuration-options.md

@@ -417,6 +417,31 @@ If enabled, all issues created by Renovate are set as confidential, even in a pu
 !!! note
     This option is applicable to GitLab only.
 
+## configMigration
+
+If enabled, Renovate will raise a pull request if config file migration is needed.
+
+We're adding new features to Renovate bot often.
+Most times you can keep using your Renovate config and benefit from the new features right away.
+But sometimes you need to change your Renovate configuration.
+To help you with this, Renovate will create config migration pull requests.
+
+Example:
+
+After we changed the [`baseBranches`](https://docs.renovatebot.com/configuration-options/#basebranches) feature, the Renovate configuration migration pull request would make this change:
+
+```diff
+{
+- "baseBranch": "main"
++ "baseBranches": ["main"]
+}
+```
+
+<!-- prettier-ignore -->
+!!! info
+    This feature writes plain JSON for `.json` files, and JSON5 for `.json5` files.
+    JSON5 content can potentially be down leveled (`.json` files) and all comments will be removed.
+
 ## configWarningReuseIssue
 
 Renovate's default behavior is to reuse/reopen a single Config Warning issue in each repository so as to keep the "noise" down.

lib/config/options/index.ts

@@ -123,6 +123,13 @@ const options: RenovateOptions[] = [
     globalOnly: true,
     cli: false,
   },
+  {
+    name: 'configMigration',
+    description: 'Enable this to get config migration PRs when needed.',
+    stage: 'repository',
+    type: 'boolean',
+    default: false,
+  },
   {
     name: 'productLinks',
     description: 'Links which are used in PRs, issues and comments.',

lib/config/types.ts

@@ -186,6 +186,7 @@ export interface RenovateConfig
     RenovateSharedConfig,
     UpdateConfig<PackageRule>,
     AssigneesAndReviewersConfig,
+    ConfigMigration,
     Record<string, unknown> {
   depName?: string;
   baseBranches?: string[];
@@ -431,6 +432,10 @@ export interface PackageRuleInputConfig extends Record<string, unknown> {
   packageRules?: (PackageRule & PackageRuleInputConfig)[];
 }
 
+export interface ConfigMigration {
+  configMigration?: boolean;
+}
+
 export interface MigratedConfig {
   isMigrated: boolean;
   migratedConfig: RenovateConfig;

lib/util/template/index.ts

@@ -143,6 +143,9 @@ const prBodyFields = [
   'table',
   'notes',
   'changelogs',
+  'hasWarningsErrors',
+  'errors',
+  'warnings',
   'configDescription',
   'controls',
   'footer',

lib/workers/repository/config-migration/branch/__fixtures__/migrated-data.json

@@ -0,0 +1,4 @@
+{
+  "filename": "renovate.json",
+  "content": "{\n  \"extends\": [\n    \":separateMajorReleases\",\n    \":prImmediately\",\n    \":renovatePrefix\",\n    \":semanticPrefixFixDepsChoreOthers\",\n    \":updateNotScheduled\",\n    \":automergeDisabled\",\n    \":maintainLockFilesDisabled\",\n    \":autodetectPinVersions\",\n    \"group:monorepos\"\n  ],\n  \"onboarding\": false,\n  \"rangeStrategy\": \"replace\",\n  \"semanticCommits\": \"enabled\",\n  \"timezone\": \"US/Central\",\n  \"baseBranches\": [\n    \"main\"\n  ]\n}\n"
+}

lib/workers/repository/config-migration/branch/__fixtures__/migrated-data.json5

@@ -0,0 +1,4 @@
+{
+  "filename": "renovate.json5",
+  "content": "{\n  extends: [\n    ':separateMajorReleases',\n    ':prImmediately',\n    ':renovatePrefix',\n    ':semanticPrefixFixDepsChoreOthers',\n    ':updateNotScheduled',\n    ':automergeDisabled',\n    ':maintainLockFilesDisabled',\n    ':autodetectPinVersions',\n    'group:monorepos',\n  ],\n  onboarding: false,\n  rangeStrategy: 'replace',\n  semanticCommits: 'enabled',\n  timezone: 'US/Central',\n  baseBranches: [\n    'main',\n  ],\n}\n"
+}

lib/workers/repository/config-migration/branch/__fixtures__/migrated.json

@@ -0,0 +1,20 @@
+{
+  "extends": [
+    ":separateMajorReleases",
+    ":prImmediately",
+    ":renovatePrefix",
+    ":semanticPrefixFixDepsChoreOthers",
+    ":updateNotScheduled",
+    ":automergeDisabled",
+    ":maintainLockFilesDisabled",
+    ":autodetectPinVersions",
+    "group:monorepos"
+  ],
+  "onboarding": false,
+  "rangeStrategy": "replace",
+  "semanticCommits": "enabled",
+  "timezone": "US/Central",
+  "baseBranches": [
+    "main"
+  ]
+}

lib/workers/repository/config-migration/branch/__fixtures__/renovate.json

@@ -0,0 +1,19 @@
+{
+  "extends": [
+    ":separateMajorReleases",
+    ":prImmediately",
+    ":renovatePrefix",
+    ":semanticPrefixFixDepsChoreOthers",
+    ":updateNotScheduled",
+    ":automergeDisabled",
+    ":maintainLockFilesDisabled",
+    ":autodetectPinVersions",
+    "group:monorepos",
+    "helpers:oddIsUnstablePackages"
+  ],
+  "onboarding": false,
+  "pinVersions": false,
+  "semanticCommits": true,
+  "timezone": "US/Central",
+  "baseBranch": "main"
+}

lib/workers/repository/config-migration/branch/__fixtures__/renovate.json5

@@ -0,0 +1,19 @@
+{
+  extends: [
+    ':separateMajorReleases',
+    ':prImmediately',
+    ':renovatePrefix',
+    ':semanticPrefixFixDepsChoreOthers',
+    ':updateNotScheduled',
+    ':automergeDisabled',
+    ':maintainLockFilesDisabled',
+    ':autodetectPinVersions',
+    'group:monorepos',
+    'helpers:oddIsUnstablePackages'
+  ],
+  onboarding: false,
+  pinVersions: false,
+  semanticCommits: true,
+  timezone: 'US/Central',
+  baseBranch: 'main' // thats a comment
+}

lib/workers/repository/config-migration/branch/commit-message.ts

@@ -0,0 +1,46 @@
+import type { RenovateConfig } from '../../../../config/types';
+import * as template from '../../../../util/template';
+import type { CommitMessage } from '../../model/commit-message';
+import { CommitMessageFactory } from '../../model/commit-message-factory';
+
+export class ConfigMigrationCommitMessageFactory {
+  private readonly config: RenovateConfig;
+
+  private readonly configFile: string;
+
+  constructor(config: RenovateConfig, configFile: string) {
+    this.config = config;
+    this.configFile = configFile;
+  }
+
+  create(): CommitMessage {
+    const { commitMessage } = this.config;
+
+    this.config.commitMessageAction =
+      this.config.commitMessageAction === 'Update'
+        ? ''
+        : this.config.commitMessageAction;
+
+    this.config.commitMessageTopic =
+      this.config.commitMessageTopic === 'dependency {{depName}}'
+        ? `Migrate config ${this.configFile}`
+        : this.config.commitMessageTopic;
+
+    this.config.commitMessageExtra = '';
+    this.config.semanticCommitScope = 'config';
+
+    const commitMessageFactory = new CommitMessageFactory(this.config);
+    const commit = commitMessageFactory.create();
+
+    if (commitMessage) {
+      commit.subject = template.compile(commitMessage, {
+        ...this.config,
+        commitMessagePrefix: '',
+      });
+    } else {
+      commit.subject = `Migrate config ${this.configFile}`;
+    }
+
+    return commit;
+  }
+}

lib/workers/repository/config-migration/branch/create.spec.ts

@@ -0,0 +1,179 @@
+import { Fixtures } from '../../../../../test/fixtures';
+import { RenovateConfig, getConfig, platform } from '../../../../../test/util';
+import { commitFiles } from '../../../../util/git';
+import { createConfigMigrationBranch } from './create';
+import type { MigratedData } from './migrated-data';
+
+jest.mock('../../../../util/git');
+
+describe('workers/repository/config-migration/branch/create', () => {
+  const raw = Fixtures.getJson('./renovate.json');
+  const indent = '  ';
+  const renovateConfig = JSON.stringify(raw, undefined, indent) + '\n';
+  const filename = 'renovate.json';
+
+  let config: RenovateConfig;
+  let migratedConfigData: MigratedData;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    config = getConfig();
+    migratedConfigData = { content: renovateConfig, filename };
+  });
+
+  describe('createConfigMigrationBranch', () => {
+    it('applies the default commit message', async () => {
+      await createConfigMigrationBranch(config, migratedConfigData);
+      expect(commitFiles).toHaveBeenCalledWith({
+        branchName: 'renovate/migrate-config',
+        files: [
+          {
+            type: 'addition',
+            path: 'renovate.json',
+            contents: renovateConfig,
+          },
+        ],
+        message: 'Migrate config renovate.json',
+        platformCommit: false,
+      });
+    });
+
+    it('commits via platform', async () => {
+      config.platformCommit = true;
+
+      await createConfigMigrationBranch(config, migratedConfigData);
+
+      expect(platform.commitFiles).toHaveBeenCalledWith({
+        branchName: 'renovate/migrate-config',
+        files: [
+          {
+            type: 'addition',
+            path: 'renovate.json',
+            contents: renovateConfig,
+          },
+        ],
+        message: 'Migrate config renovate.json',
+        platformCommit: true,
+      });
+    });
+
+    it('applies supplied commit message', async () => {
+      const message = 'We can migrate config if we want to, or we can not';
+
+      config.commitMessage = message;
+
+      await createConfigMigrationBranch(config, migratedConfigData);
+
+      expect(commitFiles).toHaveBeenCalledWith({
+        branchName: 'renovate/migrate-config',
+        files: [
+          {
+            type: 'addition',
+            path: 'renovate.json',
+            contents: renovateConfig,
+          },
+        ],
+        message: message,
+        platformCommit: false,
+      });
+    });
+
+    describe('applies the commitMessagePrefix value', () => {
+      it('to the default commit message', async () => {
+        config.commitMessagePrefix = 'PREFIX:';
+        config.commitMessage = '';
+
+        const message = `PREFIX: migrate config renovate.json`;
+        await createConfigMigrationBranch(config, migratedConfigData);
+
+        expect(commitFiles).toHaveBeenCalledWith({
+          branchName: 'renovate/migrate-config',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: renovateConfig,
+            },
+          ],
+          message: message,
+          platformCommit: false,
+        });
+      });
+
+      it('to the supplied commit message prefix, topic & action', async () => {
+        const prefix = 'PREFIX:';
+        const topic = 'thats a topic';
+        const action = 'action';
+
+        const message = `${prefix} ${action} ${topic}`;
+
+        config.commitMessagePrefix = prefix;
+        config.commitMessageTopic = topic;
+        config.commitMessageAction = action;
+
+        await createConfigMigrationBranch(config, migratedConfigData);
+
+        expect(commitFiles).toHaveBeenCalledWith({
+          branchName: 'renovate/migrate-config',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: renovateConfig,
+            },
+          ],
+          message: message,
+          platformCommit: false,
+        });
+      });
+    });
+
+    describe('applies semanticCommit prefix', () => {
+      it('to the default commit message', async () => {
+        const prefix = 'chore(config)';
+        const message = `${prefix}: migrate config renovate.json`;
+
+        config.semanticCommits = 'enabled';
+
+        await createConfigMigrationBranch(config, migratedConfigData);
+
+        expect(commitFiles).toHaveBeenCalledWith({
+          branchName: 'renovate/migrate-config',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: renovateConfig,
+            },
+          ],
+          message: message,
+          platformCommit: false,
+        });
+      });
+
+      it('to the supplied commit message topic', async () => {
+        const prefix = 'chore(config)';
+        const topic = 'supplied topic';
+        const message = `${prefix}: ${topic}`;
+
+        config.semanticCommits = 'enabled';
+        config.commitMessageTopic = topic;
+
+        await createConfigMigrationBranch(config, migratedConfigData);
+
+        expect(commitFiles).toHaveBeenCalledWith({
+          branchName: 'renovate/migrate-config',
+          files: [
+            {
+              type: 'addition',
+              path: 'renovate.json',
+              contents: renovateConfig,
+            },
+          ],
+          message: message,
+          platformCommit: false,
+        });
+      });
+    });
+  });
+});