Respect explicitly set --watchAll, and favor it over --watch (wmonk#298)

Author: DorianGrey

Diff for: packages/react-scripts/scripts/test.js

@@ -26,8 +26,12 @@ require('../config/env');
 const jest = require('jest');
 let argv = process.argv.slice(2);
 
-// Watch unless on CI or in coverage mode
-if (!process.env.CI && argv.indexOf('--coverage') < 0) {
+// Watch unless on CI, in coverage mode, or explicitly running all tests
+if (
+  !process.env.CI &&
+  argv.indexOf('--coverage') === -1 &&
+  argv.indexOf('--watchAll') === -1
+) {
   argv.push('--watch');
 }