fix watch mode

Author: MoLow

lib/internal/test_runner/runner.js

@@ -10,6 +10,7 @@ const {
   ArrayPrototypeSome,
   ArrayPrototypeSort,
   ArrayPrototypeSplice,
+  MathMax,
   Number,
   ObjectAssign,
   PromisePrototypeThen,
@@ -335,7 +336,7 @@ function runTestFile(path, root, inspectPort, filesWatcher) {
       const index = ArrayPrototypeIndexOf(root.subtests, subtest);
       if (index !== -1) {
         ArrayPrototypeSplice(root.subtests, index, 1);
-        root.waitingOn--;
+        root.waitingOn = MathMax(0, root.waitingOn - 1);
       }
     });
   }

test/parallel/test-runner-watch-mode.mjs

@@ -15,8 +15,8 @@ async function testWatch({ files, fileToUpdate }) {
   child.stdout.on('data', (data) => {
     stdout += data.toString();
     const matches = stdout.match(/test has ran/g);
-    if (matches?.length >= 1) ran1.resolve();
-    if (matches?.length >= 2) ran2.resolve();
+    if (matches?.length >= 2) ran1.resolve();
+    if (matches?.length >= 4) ran2.resolve();
   });
 
   await ran1.promise;