Test runner: Detect extra property in 'actual' but not in 'expected'. (#407)

* Test runner: Detect extra property in 'actual' but not in 'expected'.

Also update all expected.json where this would result in errors.

* Include rmExpected.js script in case it is needed again

test/utils/runFixtureTests.js

@@ -49,9 +49,6 @@ exports.runThrowTestsWithEstree = function runThrowTestsWithEstree(fixturesPath,
 };
 
 function save(test, ast) {
-  delete ast.tokens;
-  if (ast.comments && !ast.comments.length) delete ast.comments;
-
   // Ensure that RegExp are serialized as strings
   const toJSON = RegExp.prototype.toJSON;
   RegExp.prototype.toJSON = RegExp.prototype.toString;
@@ -81,6 +78,9 @@ function runTest(test, parseFunction) {
     throw err;
   }
 
+  delete ast.tokens;
+  if (ast.comments && !ast.comments.length) delete ast.comments;
+
   if (!test.expect.code && !opts.throws && !process.env.CI) {
     test.expect.loc += "on";
     return save(test, ast);
@@ -129,5 +129,15 @@ function misMatch(exp, act) {
       var mis = misMatch(exp[prop], act[prop]);
       if (mis) return addPath(mis, prop);
     }
+
+    for (var prop in act) {
+      if (prop === "__clone") {
+        continue;
+      }
+
+      if (!(prop in exp) && act[prop] !== undefined) {
+        return `Did not expect a property '${prop}'`;
+      }
+    }
   }
 }