Tests: Add checks for polyfills (for IE Jasmine).

Author: microbit-carlos

tests.html

@@ -15,7 +15,7 @@
       charset="utf-8"></script>
   <script src="static/js/jquery-2.1.4.min.js"></script>
   <script src="static/js/jquery.browser.min.js"></script>
-  <script src="static/js/microbit-fs.umd.js"></script>
+  <script src="static/js/microbit-fs.umd.min.js"></script>
   <script src="js/micropythonapi.js"></script>
   <script src="js/urlparser.js"></script>
   <script src="js/fs.js"></script>
@@ -27,5 +27,6 @@
     <script src="tests/spec/urlparser-spec.js"></script>
     <script src="tests/spec/fs-spec.js"></script>
     <script src="tests/spec/micropythonapi-spec.js"></script>
+    <script src="tests/spec/polyfill-spec.js"></script>
 </body>
 </html>

tests/spec/polyfill-spec.js

@@ -0,0 +1,60 @@
+/**
+ * The goal of this spec file is to test in Internet Explorer via Jasmin
+ * tests.html file a few of the polyfills we know are used in the editor.
+ * These are mostly coming via microbit-fs library.
+ * 
+ * In the past the build pipeline has somehow failed to include some of the
+ * polyfills (in one case the minifier has also affected this). So having a
+ * few tests here as a sanity check.
+ * 
+ * Useful links:
+ * https://kangax.github.io/compat-table/es6/
+ * https://caniuse.com/?search=es6
+ */
+
+describe("Check (some) ES6 features work.", function() {
+    /* Currently not used in microbit-fs
+    it("String.prototype.startsWith()", function() {
+        expect('random string'.startsWith('random')).toBeTruthy();
+    });
+    */
+    it("String.prototype.endsWith()", function() {
+        expect('random string'.endsWith('string')).toBeTruthy();
+    });
+
+    it("String.prototype.includes()", function() {
+        expect('random string'.includes('m s')).toBeTruthy();
+    });
+
+    it("isNaN()", function() {
+        expect(isNaN('100F')).toBeTruthy();
+    });
+    /* Currently not used in microbit-fs
+    it("Number.parseInt()", function() {
+        expect(Number.parseInt(' 0xF', 16)).toEqual(15);
+    });
+    */
+    it("Array.prototype.fill()", function() {
+        var array1 = [1, 2, 3, 4];
+        array1.fill(0, 2, 4)
+        expect(array1).toEqual([1, 2, 0, 0]);
+    });
+    /* Currently not used in microbit-fs
+    it("Array.prototype.find()", function() {
+        var array1 = [5, 12, 8, 130, 44];
+        var found = array1.find(function(element) {
+            return element > 10
+        });
+        expect(found).toEqual(12);
+    });
+    */
+    /* Currently not used in microbit-fs
+    it("Array.prototype.findIndex()", function() {
+        var array1 = [5, 12, 8, 130, 44];
+        var isLargeNumber = array1.findIndex(function(element) {
+            return element > 13
+        });
+        expect(isLargeNumber).toEqual(3);
+    });
+    */
+});