feat(@angular-devkit/build-angular): add safari-nomodule snippet

Author: samthor

packages/angular_devkit/build_angular/src/angular-cli-files/models/safari-nomodule.js

@@ -0,0 +1,33 @@
+/**
+ * Safari 10.1 supports modules, but does not support the `nomodule` attribute - it will
+ * load <script nomodule> anyway. This snippet solve this problem, but only for script
+ * tags that load external code, e.g.: <script nomodule src="nomodule.js"></script>
+ *
+ * Again: this will **not** prevent inline script, e.g.:
+ * <script nomodule>alert('no modules');</script>.
+ *
+ * This workaround is possible because Safari supports the non-standard 'beforeload' event.
+ * This allows us to trap the module and nomodule load.
+ *
+ * Note also that `nomodule` is supported in later versions of Safari - it's just 10.1 that
+ * omits this attribute.
+ */
+(function() {
+  var check = document.createElement('script');
+  if (!('noModule' in check) && 'onbeforeload' in check) {
+    var support = false;
+    document.addEventListener('beforeload', function(e) {
+      if (e.target === check) {
+        support = true;
+      } else if (!e.target.hasAttribute('nomodule') || !support) {
+        return;
+      }
+      e.preventDefault();
+    }, true);
+
+    check.type = 'module';
+    check.src = '.';
+    document.head.appendChild(check);
+    check.remove();
+  }
+}());

packages/angular_devkit/build_angular/src/angular-cli-files/models/safari-nomodule.min.js

@@ -0,0 +1,20 @@
+(function() {
+  var d = document;
+  var c = d.createElement('script');
+  if (!('noModule' in c) && 'onbeforeload' in c) {
+    var s = false;
+    d.addEventListener('beforeload', function(e) {
+      if (e.target === c) {
+        s = true;
+      } else if (!e.target.hasAttribute('nomodule') || !s) {
+        return;
+      }
+      e.preventDefault();
+    }, true);
+
+    c.type = 'module';
+    c.src = '.';
+    d.head.appendChild(c);
+    c.remove();
+  }
+}());