harness/asyncHelpers.js: Isolate assert.throwsAsync failure conditions

Author: gibson042

harness/asyncHelpers.js

@@ -63,24 +63,24 @@ assert.throwsAsync = function (expectedErrorConstructor, func, message) {
     }
     try {
       innerThenable = func();
-      if (
-        innerThenable === null ||
-        typeof innerThenable !== "object" ||
-        typeof innerThenable.then !== "function"
-      ) {
-        message +=
-          "Expected to obtain an inner promise that would reject with a" +
-          expectedErrorConstructor.name +
-          " but result was not a thenable";
-        throw new Test262Error(message);
-      }
     } catch (thrown) {
       message +=
         "Expected a " +
         expectedErrorConstructor.name +
         " to be thrown asynchronously but an exception was thrown synchronously while obtaining the inner promise";
       throw new Test262Error(message);
     }
+    if (
+      innerThenable === null ||
+      typeof innerThenable !== "object" ||
+      typeof innerThenable.then !== "function"
+    ) {
+      message +=
+        "Expected to obtain an inner promise that would reject with a" +
+        expectedErrorConstructor.name +
+        " but result was not a thenable";
+      throw new Test262Error(message);
+    }
 
     try {
       resolve(innerThenable.then(