Filter non-JS files from require when using glob with --projects (jestjs#5412)

* Add test for workspaces with a README.md in the root

* Filter projects to directories & require-able files only

This ensures `packages/*` catches folders & not README.md

* Add reference to jestjs#5199 in CHANGELOG.md

* Remove custom testDir

Author: ericclemmons

CHANGELOG.md

@@ -7,6 +7,8 @@
 
 ### Fixes
 
+* `[jest-cli]` Glob patterns ignore non-`require`-able files (e.g. `README.md`)
+  ([#5199](https://github.com/facebook/jest/issues/5199))
 * `[jest-mock]` Add backticks support (\`\`) to `mock` a certain package via the
   `__mocks__` folder. ([#5426](https://github.com/facebook/jest/pull/5426))
 * `[jest-message-util]` Prevent an `ENOENT` crash when the test file contained a

integration-tests/__tests__/multi_project_runner.test.js

@@ -154,6 +154,39 @@ test('"No tests found" message for projects', () => {
   );
 });
 
+test('projects can be workspaces with non-JS/JSON files', () => {
+  writeFiles(DIR, {
+    'package.json': JSON.stringify({
+      jest: {
+        projects: ['packages/*'],
+      },
+    }),
+    'packages/README.md': '# Packages README',
+    'packages/project1/README.md': '# Project1 README',
+    'packages/project1/__tests__/file1.test.js': `
+    const file1 = require('file1');
+    test('file1', () => {});
+    `,
+    'packages/project1/file1.js': fileContentWithProvidesModule('file1'),
+    'packages/project1/package.json': '{}',
+    'packages/project2/__tests__/file2.test.js': `
+    const file2 = require('file2');
+    test('file2', () => {});
+    `,
+    'packages/project2/file2.js': fileContentWithProvidesModule('file2'),
+    'packages/project2/package.json': '{}',
+  });
+
+  const {status, stdout, stderr} = runJest(DIR);
+
+  expect(stderr).toContain('Test Suites: 2 passed, 2 total');
+  expect(stderr).toContain('PASS packages/project1/__tests__/file1.test.js');
+  expect(stderr).toContain('PASS packages/project2/__tests__/file2.test.js');
+  expect(stderr).toContain('Ran all test suites in 2 projects.');
+  expect(stdout).toEqual('');
+  expect(status).toEqual(0);
+});
+
 test('objects in project configuration', () => {
   writeFiles(DIR, {
     '__tests__/file1.test.js': `

packages/jest-cli/src/cli/index.js

@@ -24,6 +24,7 @@ import chalk from 'chalk';
 import createContext from '../lib/create_context';
 import exit from 'exit';
 import getChangedFilesPromise from '../get_changed_files_promise';
+import fs from 'fs';
 import handleDeprecationWarnings from '../lib/handle_deprecation_warnings';
 import logDebugMessages from '../lib/log_debug_messages';
 import {print as preRunMessagePrint} from '../pre_run_message';
@@ -246,9 +247,22 @@ const getConfigs = (
   }
 
   if (projects.length > 1) {
-    const parsedConfigs = projects.map(root =>
-      readConfig(argv, root, true, configPath),
-    );
+    const parsedConfigs = projects
+      .filter(root => {
+        // Ignore globbed files that cannot be `require`d.
+        if (
+          fs.existsSync(root) &&
+          !fs.lstatSync(root).isDirectory() &&
+          !root.endsWith('.js') &&
+          !root.endsWith('.json')
+        ) {
+          return false;
+        }
+
+        return true;
+      })
+      .map(root => readConfig(argv, root, true, configPath));
+
     ensureNoDuplicateConfigs(parsedConfigs, projects);
     configs = parsedConfigs.map(({projectConfig}) => projectConfig);
     if (!hasDeprecationWarnings) {