test: add git tests

__mocks__/execa.js

@@ -0,0 +1,21 @@
+const mockStream = () => ({
+  once: jest.fn(),
+  on: jest.fn(),
+  removeListener: jest.fn(),
+  pipe: jest.fn(),
+});
+
+const mockExeca = jest.fn().mockReturnValue({
+  stdout: mockStream(),
+  stderr: mockStream(),
+  kill: () => {},
+});
+
+const mockExecaSync = jest.fn().mockReturnValue({
+  stdout: '',
+  stderr: '',
+  kill: () => {},
+});
+
+module.exports = mockExeca;
+module.exports.sync = mockExecaSync;

__mocks__/prettier.js

@@ -0,0 +1,20 @@
+const prettierMock = {
+  format: jest.fn().mockImplementation(input => 'formatted:' + input),
+  resolveConfig: {
+    sync: jest.fn().mockImplementation(file => ({ file })),
+  },
+  getSupportInfo: jest.fn().mockReturnValue({
+    languages: [
+      {
+        name: 'JavaScript',
+        extensions: ['.js'],
+      },
+      {
+        name: 'Markdown',
+        extensions: ['.md'],
+      },
+    ],
+  }),
+};
+
+module.exports = prettierMock;

package.json

@@ -40,6 +40,7 @@
     "eslint-plugin-prettier": "^2.4.0",
     "husky": "^0.14.3",
     "jest": "^22.0.4",
+    "mock-fs": "^4.4.2",
     "prettier": "1.9.2",
     "semantic-release": "^11.0.2"
   }

src/__tests__/pretty-quick.test.js

@@ -1,3 +1,17 @@
-it('has not tests', () => {
-  // yet...
+import mock from 'mock-fs';
+
+import prettyQuick from '..';
+
+jest.mock('execa');
+
+afterEach(() => mock.restore());
+
+test('throws an error when no vcs is found', () => {
+  mock({
+    'root/README.md': '',
+  });
+
+  expect(() => prettyQuick('root')).toThrowError(
+    'Unable to detect a source control manager.'
+  );
 });

src/__tests__/scm-git.test.js

@@ -0,0 +1,162 @@
+import mock from 'mock-fs';
+import execa from 'execa';
+import fs from 'fs';
+
+import prettyQuick from '..';
+
+jest.mock('execa');
+
+afterEach(() => {
+  mock.restore();
+  jest.clearAllMocks();
+});
+
+const mockGitFs = () => {
+  mock({
+    'root/.git': {},
+    'root/foo.js': 'foo()',
+    'root/bar.md': '# foo',
+  });
+  execa.sync.mockImplementation((command, args) => {
+    if (command !== 'git') {
+      throw new Error(`unexpected command: ${command}`);
+    }
+    switch (args[0]) {
+      case 'ls-files':
+        return { stdout: '' };
+      case 'diff':
+        return { stdout: './foo.js\n' + './bar.md\n' };
+      case 'add':
+        return { stdout: '' };
+      default:
+        throw new Error(`unexpected arg0: ${args[0]}`);
+    }
+  });
+};
+
+describe('with git', () => {
+  test('calls `git merge-base`', () => {
+    mock({
+      'root/.git': {},
+    });
+
+    prettyQuick('root');
+
+    expect(execa.sync).toHaveBeenCalledWith(
+      'git',
+      ['merge-base', 'HEAD', 'master'],
+      { cwd: 'root' }
+    );
+  });
+
+  test('with --staged does NOT call `git merge-base`', () => {
+    mock({
+      'root/.git': {},
+    });
+
+    prettyQuick('root');
+
+    expect(execa.sync).not.toHaveBeenCalledWith('git', [
+      'merge-base',
+      'HEAD',
+      'master',
+    ]);
+  });
+
+  test('calls `git diff --name-only` with revision', () => {
+    mock({
+      'root/.git': {},
+    });
+
+    prettyQuick('root', { since: 'banana' });
+
+    expect(execa.sync).toHaveBeenCalledWith(
+      'git',
+      ['diff', '--name-only', '--diff-filter=ACMRTUB', 'banana'],
+      { cwd: 'root' }
+    );
+  });
+
+  test('calls `git ls-files`', () => {
+    mock({
+      'root/.git': {},
+    });
+
+    prettyQuick('root', { since: 'banana' });
+
+    expect(execa.sync).toHaveBeenCalledWith(
+      'git',
+      ['ls-files', '--others', '--exclude-standard'],
+      { cwd: 'root' }
+    );
+  });
+
+  test('calls onFoundSinceRevision with return value from `git merge-base`', () => {
+    const onFoundSinceRevision = jest.fn();
+
+    mock({
+      'root/.git': {},
+    });
+    execa.sync.mockReturnValue({ stdout: 'banana' });
+
+    prettyQuick('root', { onFoundSinceRevision });
+
+    expect(onFoundSinceRevision).toHaveBeenCalledWith('git', 'banana');
+  });
+
+  test('calls onFoundChangedFiles with changed files', () => {
+    const onFoundChangedFiles = jest.fn();
+    mockGitFs();
+
+    prettyQuick('root', { since: 'banana', onFoundChangedFiles });
+
+    expect(onFoundChangedFiles).toHaveBeenCalledWith(['./foo.js', './bar.md']);
+  });
+
+  test('calls onWriteFile with changed files', () => {
+    const onWriteFile = jest.fn();
+    mockGitFs();
+
+    prettyQuick('root', { since: 'banana', onWriteFile });
+
+    expect(onWriteFile).toHaveBeenCalledWith('./foo.js');
+    expect(onWriteFile).toHaveBeenCalledWith('./bar.md');
+  });
+
+  test('writes formatted files to disk', () => {
+    const onWriteFile = jest.fn();
+
+    mockGitFs();
+
+    prettyQuick('root', { since: 'banana', onWriteFile });
+
+    expect(fs.readFileSync('root/foo.js', 'utf8')).toEqual('formatted:foo()');
+    expect(fs.readFileSync('root/bar.md', 'utf8')).toEqual('formatted:# foo');
+  });
+
+  test('with --staged stages changed files', () => {
+    mockGitFs();
+
+    prettyQuick('root', { since: 'banana', staged: true });
+
+    expect(execa.sync).toHaveBeenCalledWith('git', ['add', './foo.js'], {
+      cwd: 'root',
+    });
+    expect(execa.sync).toHaveBeenCalledWith('git', ['add', './bar.md'], {
+      cwd: 'root',
+    });
+  });
+
+  test('without --staged does NOT stage changed files', () => {
+    mockGitFs();
+
+    prettyQuick('root', { since: 'banana' });
+
+    expect(execa.sync).not.toHaveBeenCalledWith('git', ['add', './foo.js'], {
+      cwd: 'root',
+    });
+    expect(execa.sync).not.toHaveBeenCalledWith('git', ['add', './bar.md'], {
+      cwd: 'root',
+    });
+  });
+});

src/formatFiles.js

@@ -1,20 +1,22 @@
 import { readFileSync, writeFileSync } from 'fs';
 import { resolveConfig, format } from 'prettier';
+import { join } from 'path';
 
-export default (files, { config, onWriteFile }) => {
-  for (const file of files) {
+export default (directory, files, { config, onWriteFile } = {}) => {
+  for (const relative of files) {
+    const file = join(directory, relative);
     const options = resolveConfig.sync(file, { config });
     const input = readFileSync(file, 'utf8');
     const output = format(
       input,
-      Object.assign(options, {
+      Object.assign({}, options, {
         filepath: file,
       })
     );
 
     if (output !== input) {
       writeFileSync(file, output);
-      onWriteFile && onWriteFile(file);
+      onWriteFile && onWriteFile(relative);
     }
   }
 };

src/index.js

@@ -14,7 +14,7 @@ export default (
     onFoundSinceRevision,
     onFoundChangedFiles,
     onWriteFile,
-  }
+  } = {}
 ) => {
   const scm = scms(directory);
   if (!scm) {
@@ -27,17 +27,16 @@ export default (
 
   const changedFiles = scm
     .getChangedFiles(directory, revision)
-    .map(file => relative(directory, file))
     .filter(isSupportedExtension)
     .filter(createIgnorer(directory));
 
   onFoundChangedFiles && onFoundChangedFiles(changedFiles);
 
-  formatFiles(changedFiles, {
+  formatFiles(directory, changedFiles, {
     config,
     onWriteFile: file => {
-      onWriteFile(file);
-      scm.stageFile(directory, file);
+      onWriteFile && onWriteFile(file);
+      staged && scm.stageFile(directory, file);
     },
   });
 };

yarn.lock

@@ -3114,6 +3114,10 @@ minimist@~0.0.1:
   dependencies:
     minimist "0.0.8"
 
+mock-fs@^4.4.2:
+  version "4.4.2"
+  resolved "https://registry.yarnpkg.com/mock-fs/-/mock-fs-4.4.2.tgz#09dec5313f97095a450be6aa2ad8ab6738d63d6b"
+
 modify-values@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/modify-values/-/modify-values-1.0.0.tgz#e2b6cdeb9ce19f99317a53722f3dbf5df5eaaab2"