feat(managers/git-submodules): support updating git-tag versions

lib/modules/manager/git-submodules/__fixtures__/.gitmodules.8

@@ -0,0 +1,12 @@
+[submodule "renovate1"]
+	path = deps/renovate1
+	url = https://github.com/renovatebot/renovate.git
+	branch = v0.0.1
+[submodule "renovate2"]
+	path = deps/renovate2
+	url = https://github.com/renovatebot/renovate.git
+	branch = 0.0.1
+[submodule "renovate3"]
+	path = deps/renovate3
+	url = https://github.com/renovatebot/renovate.git
+	branch = not-a-semver

lib/modules/manager/git-submodules/extract.spec.ts

@@ -118,6 +118,7 @@ describe('modules/manager/git-submodules/extract', () => {
     it('default to master if no branch can be detected', async () => {
       const res = await extractPackageFile('', '.gitmodules.2', {});
       expect(res?.deps).toHaveLength(1);
+      expect(res?.deps[0].versioning).toBeUndefined();
       expect(res?.deps[0].currentValue).toBe('master');
     });
 
@@ -336,5 +337,34 @@ describe('modules/manager/git-submodules/extract', () => {
         ],
       });
     });
+
+    it('given semver version is extracted from branch and versioning is set to semver', async () => {
+      const res = await extractPackageFile('', '.gitmodules.8', {});
+      expect(res).toEqual({
+        datasource: 'git-refs',
+        deps: [
+          {
+            currentDigest: '4b825dc642cb6eb9a060e54bf8d69288fbee4904',
+            currentValue: 'v0.0.1',
+            depName: 'deps/renovate1',
+            packageName: 'https://github.com/renovatebot/renovate.git',
+            versioning: 'semver',
+          },
+          {
+            currentDigest: '4b825dc642cb6eb9a060e54bf8d69288fbee4904',
+            currentValue: '0.0.1',
+            depName: 'deps/renovate2',
+            packageName: 'https://github.com/renovatebot/renovate.git',
+            versioning: 'semver',
+          },
+          {
+            currentDigest: '4b825dc642cb6eb9a060e54bf8d69288fbee4904',
+            currentValue: 'not-a-semver',
+            packageName: 'https://github.com/renovatebot/renovate.git',
+            depName: 'deps/renovate3',
+          },
+        ],
+      });
+    });
   });
 });

lib/modules/manager/git-submodules/extract.ts

@@ -8,6 +8,7 @@ import { simpleGitConfig } from '../../../util/git/config';
 import { getHttpUrl } from '../../../util/git/url';
 import { regEx } from '../../../util/regex';
 import { GitRefsDatasource } from '../../datasource/git-refs';
+import * as semVerVersioning from '../../versioning/semver';
 import type { ExtractConfig, PackageFileContent } from '../types';
 import type { GitModule } from './types';
 
@@ -138,6 +139,9 @@ export default async function extractPackageFile(
         packageName: httpSubModuleUrl,
         currentValue,
         currentDigest,
+        ...(semVerVersioning.api.isVersion(currentValue)
+          ? { versioning: semVerVersioning.id }
+          : {}),
       });
     } catch (err) /* istanbul ignore next */ {
       logger.warn(

lib/modules/manager/git-submodules/readme.md

@@ -11,6 +11,21 @@ You can customize the per-submodule checks of the git-submodules manager like th
 }
 ```
 
+### Updating to Specific Tag Values
+
+If you want to update your Git submodules to a specific tag, you can set the desired tag as the `branch` in your `.gitmodules` file.
+Renovate will then automatically update this version to the latest Git tag.
+
+```ini
+[submodule "renovate"]
+  path = deps/renovate
+  url = https://github.com/renovatebot/renovate.git
+  branch = v0.0.1
+```
+
+**Note:** Using this approach will disrupt the native git submodule update experience when using `git submodule update --remote`. You may encounter an error like `fatal: Unable to find refs/remotes/origin/v0.0.1 revision in submodule path...` because Git can only update submodules when tracking a branch.
+To manually update the submodule, navigate to the submodule directory and run the following commands: `git fetch && git checkout <new tag>`.
+
 ### Private Modules Authentication
 
 Before running the `git` commands to update the submodules, Renovate exports `git` [`insteadOf`](https://git-scm.com/docs/git-config#Documentation/git-config.txt-urlltbasegtinsteadOf) directives in environment variables.

lib/modules/manager/git-submodules/update.spec.ts

@@ -2,11 +2,13 @@ import { mock } from 'jest-mock-extended';
 import { SimpleGit, simpleGit } from 'simple-git';
 import { DirectoryResult, dir } from 'tmp-promise';
 import { join } from 'upath';
+import { fs } from '../../../../test/util';
 import { GlobalConfig } from '../../../config/global';
 import type { RepoGlobalConfig } from '../../../config/types';
 import * as hostRules from '../../../util/host-rules';
 import type { Upgrade } from '../types';
 import { updateDependency } from '.';
+jest.mock('../../../util/fs');
 
 jest.mock('simple-git');
 const simpleGitFactoryMock = simpleGit as jest.Mock<Partial<SimpleGit>>;
@@ -88,6 +90,51 @@ describe('modules/manager/git-submodules/update', () => {
       });
     });
 
+    it('update gitmodule branch value if value changed', async () => {
+      gitMock.submoduleUpdate.mockResolvedValue('');
+      gitMock.checkout.mockResolvedValue('');
+      const updatedGitModules = `[submodule "renovate"]
+      path = deps/renovate
+      url = https://github.com/renovatebot/renovate.git
+      branch = v0.0.2`;
+      fs.readLocalFile.mockResolvedValueOnce(updatedGitModules);
+
+      upgrade = {
+        depName: 'renovate',
+        currentValue: 'v0.0.1',
+        newValue: 'v0.0.2',
+        packageFile: '.gitmodules',
+      };
+      const update = await updateDependency({
+        fileContent: '',
+        upgrade,
+      });
+      expect(update).toBe(updatedGitModules);
+      expect(gitMock.subModule).toHaveBeenCalledWith([
+        'set-branch',
+        '--branch',
+        'v0.0.2',
+        'renovate',
+      ]);
+    });
+
+    it('do not update gitmodule branch value if value not changed', async () => {
+      gitMock.submoduleUpdate.mockResolvedValue('');
+      gitMock.checkout.mockResolvedValue('');
+      upgrade = {
+        depName: 'renovate',
+        currentValue: 'main',
+        newValue: 'main',
+        packageFile: '.gitmodules',
+      };
+      const update = await updateDependency({
+        fileContent: '',
+        upgrade,
+      });
+      expect(update).toBe('');
+      expect(gitMock.subModule).toHaveBeenCalledTimes(0);
+    });
+
     it('returns content on update and uses git environment variables for git-tags/git-refs', async () => {
       gitMock.submoduleUpdate.mockResolvedValue('');
       gitMock.checkout.mockResolvedValue('');

lib/modules/manager/git-submodules/update.ts

@@ -2,6 +2,7 @@ import Git from 'simple-git';
 import upath from 'upath';
 import { GlobalConfig } from '../../../config/global';
 import { logger } from '../../../logger';
+import { readLocalFile } from '../../../util/fs';
 import { getGitEnvironmentVariables } from '../../../util/git/auth';
 import type { UpdateDependencyConfig } from '../types';
 
@@ -26,6 +27,16 @@ export default async function updateDependency({
   try {
     await git.submoduleUpdate(['--init', upgrade.depName!]);
     await submoduleGit.checkout([upgrade.newDigest!]);
+    if (upgrade.newValue && upgrade.currentValue !== upgrade.newValue) {
+      await git.subModule([
+        'set-branch',
+        '--branch',
+        upgrade.newValue,
+        upgrade.depName!,
+      ]);
+      const updatedPackageContent = await readLocalFile(upgrade.packageFile!);
+      return updatedPackageContent!.toString();
+    }
     return fileContent;
   } catch (err) {
     logger.debug({ err }, 'submodule checkout error');