Add __DEV__ to jest environment

build/jest-config.js

@@ -3,8 +3,11 @@
 module.exports = {
   cache: true,
   globals: {
+    // Parity with create-universal-package globals.
+    // https://github.com/rtsao/create-universal-package#globals
     __NODE__: process.env.JEST_ENV === 'node',
     __BROWSER__: process.env.JEST_ENV === 'jsdom',
+    __DEV__: process.env.NODE_ENV !== 'production',
   },
   rootDir: process.cwd(),
   setupFiles: [

test/cli/test-app.js

@@ -157,3 +157,14 @@ test('`fusion test-app` coverage', async t => {
   t.ok(response.stdout.includes('Uncovered Lines'));
   t.end();
 });
+
+test('`fusion test-app` environment variables', async t => {
+  const dir = path.resolve(__dirname, '../fixtures/test-jest-app');
+  const args = `test-app --dir=${dir} --configPath=../../../build/jest-config.js --coverage --match=environment-variables`;
+
+  const cmd = `require('${runnerPath}').run('${args}')`;
+  const response = await exec(`node -e "${cmd}"`);
+  t.equal(countTests(response.stderr), 2, 'ran 2 tests');
+
+  t.end();
+});

test/fixtures/test-jest-app/__tests__/environment-variables.js

@@ -0,0 +1,5 @@
+import {test} from 'fusion-test-utils';
+
+test('__DEV__ environment variable is set', assert => {
+  assert.equal(__DEV__, true);
+});