Fix test runner breaking

The test runner script tried to pass the Jest config as
stringified JSON, but that was breaking for me somehow.

Sidestepped the problem by writing the settings to disk instead
and pointing Jest to that file.

Author: markerikson

.gitignore

@@ -10,6 +10,7 @@ test/**/lcov.info
 test/**/lcov-report
 test/react/*/test/**/*.spec.js
 test/react/**/src
+test/jest-config.json
 lcov.info
 
 lib/core/metadata.js

test/run-tests.js

@@ -1,4 +1,6 @@
 const npmRun = require('npm-run')
+const fs = require('fs')
+const path = require('path')
 const LATEST_VERSION = '16.6'
 const version = process.env.REACT || LATEST_VERSION
 
@@ -27,7 +29,13 @@ if (version.toLowerCase() === 'all') {
   }
 }
 
+const configFilePath = path.join(__dirname, 'jest-config.json')
+
+fs.writeFileSync(configFilePath, JSON.stringify(jestConfig))
+
+const commandLine = `jest -c "${configFilePath}" ${process.argv.slice(2).join(' ')}`
+
 npmRun.execSync(
-  `jest -c '${JSON.stringify(jestConfig)}' ${process.argv.slice(2).join(' ')}`,
+  commandLine,
   { stdio: 'inherit' }
 )