(types): improve typings for Jest config

jaredpalmer · Mar 9, 2020 · 9fef652 · 9fef652
1 parent f19fa61
commit 9fef652
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/src/createJestConfig.ts b/src/createJestConfig.ts
@@ -1,8 +1,12 @@
+import { Config } from '@jest/types';
+
+export type JestConfigOptions = Partial<Config.InitialOptions>;
+
 export function createJestConfig(
   _: (relativePath: string) => void,
   rootDir: string
-) {
-  const config = {
+): JestConfigOptions {
+  const config: JestConfigOptions = {
     transform: {
       '.(ts|tsx)$': require.resolve('ts-jest/dist'),
       '.(js|jsx)$': require.resolve('babel-jest'), // jest's default

diff --git a/src/index.ts b/src/index.ts
@@ -24,7 +24,7 @@ import semver from 'semver';
 import { paths } from './constants';
 import * as Messages from './messages';
 import { createBuildConfigs } from './createBuildConfigs';
-import { createJestConfig } from './createJestConfig';
+import { createJestConfig, JestConfigOptions } from './createJestConfig';
 import { createEslintConfig } from './createEslintConfig';
 import {
   resolveApp,
@@ -499,7 +499,7 @@ prog
     });
 
     const argv = process.argv.slice(2);
-    let jestConfig = {
+    let jestConfig: JestConfigOptions = {
       ...createJestConfig(
         relativePath => path.resolve(__dirname, '..', relativePath),
         opts.config ? path.dirname(opts.config) : paths.appRoot
@@ -511,7 +511,7 @@ prog
     const defaultPathExists = await fs.pathExists(paths.jestConfig);
     if (opts.config || defaultPathExists) {
       const jestConfigPath = resolveApp(opts.config || paths.jestConfig);
-      const jestConfigContents = require(jestConfigPath);
+      const jestConfigContents: JestConfigOptions = require(jestConfigPath);
       jestConfig = { ...jestConfig, ...jestConfigContents };
     }