Add functional tests

This commit adds tests which run the script within a separate shell
instance and verifies that the script makes the appropriate changes to
the repo.

I've tried to make these functional tests as readable as possible. In
order to do that, I created a small framework which replicates the
environment in which the script will run and then allows that
environment to be modified per-test to suit the assertions being made.

package.json

@@ -49,6 +49,7 @@
     "@types/yargs": "^17.0.10",
     "@typescript-eslint/eslint-plugin": "^4.21.0",
     "@typescript-eslint/parser": "^4.21.0",
+    "deepmerge": "^4.2.2",
     "eslint": "^7.23.0",
     "eslint-config-prettier": "^8.1.0",
     "eslint-plugin-import": "^2.22.1",

src/fs.test.ts

@@ -4,7 +4,7 @@ import util from 'util';
 import rimraf from 'rimraf';
 import { when } from 'jest-when';
 import * as actionUtils from '@metamask/action-utils';
-import { withSandbox } from '../tests/unit/helpers';
+import { withSandbox } from '../tests/helpers';
 import {
   readFile,
   writeFile,

src/functional.test.ts

@@ -0,0 +1,252 @@
+import { withMonorepoProjectEnvironment } from '../tests/functional/helpers/with';
+import { buildChangelog } from '../tests/functional/helpers/utils';
+
+describe('create-release-branch (functional)', () => {
+  describe('against a monorepo with independent versions', () => {
+    it('updates the version of the root package to be the current date along with the versions of the specified packages', async () => {
+      await withMonorepoProjectEnvironment(
+        {
+          packages: {
+            $root$: {
+              name: '@scope/monorepo',
+              version: '2022.1.1',
+              directoryPath: '.',
+            },
+            a: {
+              name: '@scope/a',
+              version: '0.1.2',
+              directoryPath: 'packages/a',
+            },
+            b: {
+              name: '@scope/b',
+              version: '1.1.4',
+              directoryPath: 'packages/b',
+            },
+            c: {
+              name: '@scope/c',
+              version: '2.0.13',
+              directoryPath: 'packages/c',
+            },
+            d: {
+              name: '@scope/d',
+              version: '1.2.3',
+              directoryPath: 'packages/d',
+            },
+            e: {
+              name: '@scope/e',
+              version: '0.0.3',
+              directoryPath: 'packages/e',
+            },
+          },
+          workspaces: {
+            '.': ['packages/*'],
+          },
+          today: new Date('2022-06-24'),
+        },
+        async (environment) => {
+          await environment.runTool({
+            releaseSpecification: {
+              packages: {
+                a: 'major',
+                b: 'minor',
+                c: 'patch',
+                d: '1.2.4',
+              },
+            },
+          });
+
+          expect(await environment.readJsonFile('package.json')).toMatchObject({
+            version: '2022.6.24',
+          });
+          expect(
+            await environment.readJsonFileWithinPackage('a', 'package.json'),
+          ).toMatchObject({
+            version: '1.0.0',
+          });
+          expect(
+            await environment.readJsonFileWithinPackage('b', 'package.json'),
+          ).toMatchObject({
+            version: '1.2.0',
+          });
+          expect(
+            await environment.readJsonFileWithinPackage('c', 'package.json'),
+          ).toMatchObject({
+            version: '2.0.14',
+          });
+          expect(
+            await environment.readJsonFileWithinPackage('d', 'package.json'),
+          ).toMatchObject({
+            version: '1.2.4',
+          });
+          expect(
+            await environment.readJsonFileWithinPackage('e', 'package.json'),
+          ).toMatchObject({
+            version: '0.0.3',
+          });
+        },
+      );
+    });
+
+    it("updates each of the specified package's changelog by adding a new section which lists all commits concerning the package over the entire history of the repo", async () => {
+      await withMonorepoProjectEnvironment(
+        {
+          packages: {
+            $root$: {
+              name: '@scope/monorepo',
+              version: '1.0.0',
+              directoryPath: '.',
+            },
+            a: {
+              name: '@scope/a',
+              version: '1.0.0',
+              directoryPath: 'packages/a',
+            },
+            b: {
+              name: '@scope/b',
+              version: '1.0.0',
+              directoryPath: 'packages/b',
+            },
+          },
+          workspaces: {
+            '.': ['packages/*'],
+          },
+          createInitialCommit: false,
+        },
+        async (environment) => {
+          // Create an initial commit
+          await environment.writeFileWithinPackage(
+            'a',
+            'CHANGELOG.md',
+            buildChangelog(`
+              ## [Unreleased]
+
+              [Unreleased]: https://github.com/example-org/example-repo
+            `),
+          );
+          await environment.writeFileWithinPackage(
+            'b',
+            'CHANGELOG.md',
+            buildChangelog(`
+              ## [Unreleased]
+
+              [Unreleased]: https://github.com/example-org/example-repo
+            `),
+          );
+          await environment.createCommit('Initial commit');
+
+          // Create another commit that only changes "a"
+          await environment.writeFileWithinPackage(
+            'a',
+            'dummy.txt',
+            'Some content',
+          );
+          await environment.createCommit('Update "a"');
+
+          // Run the tool
+          await environment.runTool({
+            releaseSpecification: {
+              packages: {
+                a: 'major',
+                b: 'major',
+              },
+            },
+          });
+
+          // Both changelogs should get updated, with an additional
+          // commit listed for "a"
+          expect(
+            await environment.readFileWithinPackage('a', 'CHANGELOG.md'),
+          ).toStrictEqual(
+            buildChangelog(`
+              ## [Unreleased]
+
+              ## [2.0.0]
+              ### Uncategorized
+              - Update "a"
+              - Initial commit
+
+              [Unreleased]: https://github.com/example-org/example-repo/compare/v2.0.0...HEAD
+              [2.0.0]: https://github.com/example-org/example-repo/releases/tag/v2.0.0
+            `),
+          );
+          expect(
+            await environment.readFileWithinPackage('b', 'CHANGELOG.md'),
+          ).toStrictEqual(
+            buildChangelog(`
+              ## [Unreleased]
+
+              ## [2.0.0]
+              ### Uncategorized
+              - Initial commit
+
+              [Unreleased]: https://github.com/example-org/example-repo/compare/v2.0.0...HEAD
+              [2.0.0]: https://github.com/example-org/example-repo/releases/tag/v2.0.0
+            `),
+          );
+        },
+      );
+    });
+
+    it('commits the updates and saves the new commit to a new branch, then switches to that branch', async () => {
+      await withMonorepoProjectEnvironment(
+        {
+          packages: {
+            $root$: {
+              name: '@scope/monorepo',
+              version: '1.0.0',
+              directoryPath: '.',
+            },
+            a: {
+              name: '@scope/a',
+              version: '1.0.0',
+              directoryPath: 'packages/a',
+            },
+          },
+          workspaces: {
+            '.': ['packages/*'],
+          },
+          today: new Date('2022-06-24'),
+        },
+        async (environment) => {
+          await environment.runTool({
+            releaseSpecification: {
+              packages: {
+                a: 'major',
+              },
+            },
+          });
+
+          // The most recent commit should be called the right thing, and
+          // should be the current one, and should also be called
+          // `release/YYYY-MM-DD`
+          const mostRecentCommitInfo = (
+            await environment.runCommand('git', [
+              'log',
+              '--pretty=%D%x09%s%x09%H',
+              '--date-order',
+              '--max-count=1',
+            ])
+          ).stdout
+            .trim()
+            .split('\x09');
+          expect(mostRecentCommitInfo.slice(0, -1)).toStrictEqual([
+            'HEAD -> release/2022-06-24',
+            'Release 2022-06-24',
+          ]);
+          // The most recent branch should point to the most recent commit
+          const commitIdOfMostRecentBranch = (
+            await environment.runCommand('git', [
+              'rev-list',
+              '--branches',
+              '--date-order',
+              '--max-count=1',
+            ])
+          ).stdout.trim();
+          expect(mostRecentCommitInfo[2]).toStrictEqual(
+            commitIdOfMostRecentBranch,
+          );
+        },
+      );
+    });
+  });
+});

src/monorepo-workflow-operations.test.ts

@@ -1,11 +1,8 @@
 import fs from 'fs';
 import path from 'path';
 import { SemVer } from 'semver';
-import {
-  withSandbox,
-  buildMockPackage,
-  buildMockProject,
-} from '../tests/unit/helpers';
+import { withSandbox } from '../tests/helpers';
+import { buildMockPackage, buildMockProject } from '../tests/unit/helpers';
 import { followMonorepoWorkflow } from './monorepo-workflow-operations';
 import * as editorModule from './editor';
 import * as envModule from './env';

src/package-manifest.test.ts

@@ -1,7 +1,7 @@
 import fs from 'fs';
 import path from 'path';
 import { SemVer } from 'semver';
-import { withSandbox } from '../tests/unit/helpers';
+import { withSandbox } from '../tests/helpers';
 import { readPackageManifest } from './package-manifest';
 
 describe('package-manifest', () => {

src/package.test.ts

@@ -2,13 +2,10 @@ import fs from 'fs';
 import path from 'path';
 import { when } from 'jest-when';
 import * as autoChangelog from '@metamask/auto-changelog';
-import {
-  buildMockProject,
-  buildMockManifest,
-  withSandbox,
-} from '../tests/unit/helpers';
-import { readPackage, updatePackage } from './package';
+import { withSandbox } from '../tests/helpers';
+import { buildMockProject, buildMockManifest } from '../tests/unit/helpers';
 import * as fsModule from './fs';
+import { readPackage, updatePackage } from './package';
 import * as packageManifestModule from './package-manifest';
 
 jest.mock('@metamask/auto-changelog');

src/project.test.ts

@@ -1,11 +1,8 @@
 import fs from 'fs';
 import path from 'path';
 import { when } from 'jest-when';
-import {
-  buildMockManifest,
-  buildMockPackage,
-  withSandbox,
-} from '../tests/unit/helpers';
+import { withSandbox } from '../tests/helpers';
+import { buildMockManifest, buildMockPackage } from '../tests/unit/helpers';
 import { readProject } from './project';
 import * as packageModule from './package';
 import * as repoModule from './repo';

src/release-specification.test.ts

@@ -4,11 +4,8 @@ import { when } from 'jest-when';
 import { MockWritable } from 'stdio-mock';
 import YAML from 'yaml';
 import { SemVer } from 'semver';
-import {
-  withSandbox,
-  buildMockProject,
-  buildMockPackage,
-} from '../tests/unit/helpers';
+import { withSandbox } from '../tests/helpers';
+import { buildMockProject, buildMockPackage } from '../tests/unit/helpers';
 import {
   generateReleaseSpecificationTemplateForMonorepo,
   waitForUserToEditReleaseSpecification,

tests/functional/helpers/constants.ts

@@ -0,0 +1,10 @@
+import path from 'path';
+
+export const ROOT_DIR = path.resolve(__dirname, '../../..');
+export const TOOL_EXECUTABLE_PATH = path.join(ROOT_DIR, 'src', 'cli.ts');
+export const TS_NODE_PATH = path.join(
+  ROOT_DIR,
+  'node_modules',
+  '.bin',
+  'ts-node',
+);