chore: simplify types in jest-changed-files

packages/jest-changed-files/package.json

@@ -10,6 +10,7 @@
   "main": "build/index.js",
   "types": "build/index.d.ts",
   "dependencies": {
+    "@jest/types": "^24.1.0",
     "execa": "^1.0.0",
     "throat": "^4.0.0"
   },

packages/jest-changed-files/src/git.ts

@@ -8,13 +8,14 @@
 
 import path from 'path';
 import execa from 'execa';
+import {Config} from '@jest/types';
 
-import {Path, Options, SCMAdapter} from './types';
+import {SCMAdapter} from './types';
 
 const findChangedFilesUsingCommand = async (
   args: Array<string>,
-  cwd: Path,
-): Promise<Array<Path>> => {
+  cwd: Config.Path,
+): Promise<Array<Config.Path>> => {
   const result = await execa('git', args, {cwd});
 
   return result.stdout
@@ -24,14 +25,12 @@ const findChangedFilesUsingCommand = async (
 };
 
 const adapter: SCMAdapter = {
-  findChangedFiles: async (
-    cwd: string,
-    options?: Options,
-  ): Promise<Array<Path>> => {
+  findChangedFiles: async (cwd, options) => {
     const changedSince: string | undefined =
       options && (options.withAncestor ? 'HEAD^' : options.changedSince);
 
-    const includePaths: Array<Path> = (options && options.includePaths) || [];
+    const includePaths: Array<Config.Path> =
+      (options && options.includePaths) || [];
 
     if (options && options.lastCommit) {
       return findChangedFilesUsingCommand(
@@ -72,7 +71,7 @@ const adapter: SCMAdapter = {
     }
   },
 
-  getRoot: async (cwd: string): Promise<string | null> => {
+  getRoot: async cwd => {
     const options = ['rev-parse', '--show-toplevel'];
 
     try {

packages/jest-changed-files/src/hg.ts

@@ -8,17 +8,16 @@
 
 import path from 'path';
 import execa from 'execa';
+import {Config} from '@jest/types';
 
-import {Path, Options, SCMAdapter} from './types';
+import {SCMAdapter} from './types';
 
 const env = {...process.env, HGPLAIN: '1'};
 
 const adapter: SCMAdapter = {
-  findChangedFiles: async (
-    cwd: string,
-    options: Options,
-  ): Promise<Array<Path>> => {
-    const includePaths: Array<Path> = (options && options.includePaths) || [];
+  findChangedFiles: async (cwd, options) => {
+    const includePaths: Array<Config.Path> =
+      (options && options.includePaths) || [];
 
     const args = ['status', '-amnu'];
     if (options && options.withAncestor) {
@@ -38,7 +37,7 @@ const adapter: SCMAdapter = {
       .map(changedPath => path.resolve(cwd, changedPath));
   },
 
-  getRoot: async (cwd: Path): Promise<Path | null | undefined> => {
+  getRoot: async cwd => {
     try {
       const result = await execa('hg', ['root'], {cwd, env});
 

packages/jest-changed-files/src/index.ts

@@ -7,11 +7,18 @@
  */
 
 import throat from 'throat';
+import {Config} from '@jest/types';
 
-import {Path, ChangedFilesPromise, Options, Repos} from './types';
+import {ChangedFilesPromise, Options, Repos, SCMAdapter} from './types';
 import git from './git';
 import hg from './hg';
 
+type RootPromise = ReturnType<SCMAdapter['getRoot']>;
+
+function notEmpty<T>(value: T | null | undefined): value is T {
+  return value != null;
+}
+
 // This is an arbitrary number. The main goal is to prevent projects with
 // many roots (50+) from spawning too many processes at once.
 const mutex = throat(5);
@@ -20,7 +27,7 @@ const findGitRoot = (dir: string) => mutex(() => git.getRoot(dir));
 const findHgRoot = (dir: string) => mutex(() => hg.getRoot(dir));
 
 export const getChangedFilesForRoots = async (
-  roots: Path[],
+  roots: Config.Path[],
   options: Options,
 ): ChangedFilesPromise => {
   const repos = await findRepos(roots);
@@ -48,22 +55,22 @@ export const getChangedFilesForRoots = async (
   return {changedFiles, repos};
 };
 
-export const findRepos = async (roots: Path[]): Promise<Repos> => {
+export const findRepos = async (roots: Config.Path[]): Promise<Repos> => {
   const gitRepos = await Promise.all(
-    roots.reduce<Promise<string | null | undefined>[]>(
+    roots.reduce<RootPromise[]>(
       (promises, root) => promises.concat(findGitRoot(root)),
       [],
     ),
   );
   const hgRepos = await Promise.all(
-    roots.reduce<Promise<string | null | undefined>[]>(
+    roots.reduce<RootPromise[]>(
       (promises, root) => promises.concat(findHgRoot(root)),
       [],
     ),
   );
 
   return {
-    git: new Set(gitRepos.filter(Boolean) as string[]),
-    hg: new Set(hgRepos.filter(Boolean) as string[]),
+    git: new Set(gitRepos.filter(notEmpty)),
+    hg: new Set(hgRepos.filter(notEmpty)),
   };
 };

packages/jest-changed-files/src/types.ts

@@ -3,26 +3,28 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
  */
 
-export type Path = string;
+import {Config} from '@jest/types';
 
 export type Options = {
   lastCommit?: boolean;
   withAncestor?: boolean;
   changedSince?: string;
-  includePaths?: Array<Path>;
+  includePaths?: Array<Config.Path>;
 };
 
-export type ChangedFiles = Set<Path>;
-export type Repos = {git: Set<Path>; hg: Set<Path>};
+type ChangedFiles = Set<Config.Path>;
+export type Repos = {git: ChangedFiles; hg: ChangedFiles};
 export type ChangedFilesPromise = Promise<{
   repos: Repos;
   changedFiles: ChangedFiles;
 }>;
 
 export type SCMAdapter = {
-  findChangedFiles: (cwd: Path, options: Options) => Promise<Array<Path>>;
-  getRoot: (cwd: Path) => Promise<Path | null | undefined>;
+  findChangedFiles: (
+    cwd: Config.Path,
+    options: Options,
+  ) => Promise<Array<Config.Path>>;
+  getRoot: (cwd: Config.Path) => Promise<Config.Path | null>;
 };

packages/jest-changed-files/tsconfig.json

@@ -3,5 +3,8 @@
   "compilerOptions": {
     "rootDir": "src",
     "outDir": "build"
-  }
+  },
+  "references": [
+    {"path":  "../jest-types"}
+  ]
 }