add inheritance type check to tests

test/fixtures/transformation/es6-classes/accessing-super-class/expected.js

@@ -2,6 +2,9 @@
 
 var _slice = Array.prototype.slice;
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js

@@ -1,6 +1,9 @@
 "use strict";
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/es6-classes/calling-super-properties/expected.js

@@ -1,6 +1,9 @@
 "use strict";
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/es6-classes/constructor/expected.js

@@ -1,6 +1,9 @@
 "use strict";
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/es6-classes/super-class-id-member-expression/expected.js

@@ -1,6 +1,9 @@
 "use strict";
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/es6-classes/super-class/expected.js

@@ -1,6 +1,9 @@
 "use strict";
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,

test/fixtures/transformation/optional-proto-to-assign/class/expected.js

@@ -11,6 +11,9 @@ var _defaults = function (obj, defaults) {
 };
 
 var _inherits = function (child, parent) {
+  if (typeof parent !== "function" && parent !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+  }
   child.prototype = Object.create(parent && parent.prototype, {
     constructor: {
       value: child,