fix(runner): consider event for failure detection

To detect failures we were relying on Busted's exit status. This commit
changes the logic to use the events emitted by Busted to detect failures
instead.

src/runner.js

@@ -48,10 +48,18 @@ const runner = async (
 
   const runTest = async (test) => {
     const { suite, exclude_tags, environment, filename } = test
+    let failed = false
     const listener = await bustedEventListener(
       bustedEventPath,
       ({ event, args }) => {
         switch (event) {
+          case 'failure':
+          case 'failure:it':
+          case 'error':
+          case 'error:it':
+            failed = true
+            break
+
           case 'file:end': {
             const { duration } = args[0]
             appendToFile(
@@ -91,7 +99,7 @@ const runner = async (
 
       await saveTestResult(test, exitStatus, output)
 
-      if (exitStatus !== 0) {
+      if (exitStatus !== 0 || failed) {
         console.error(`\nTest failed with exit status: ${exitStatus} ($output)`)
         return false
       }