PWA

node_modules/workbox-build/src/lib/modify-url-prefix-transform.ts

@@ -0,0 +1,61 @@
+/*
+  Copyright 2018 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+
+import {errors} from './errors';
+import {escapeRegExp} from './escape-regexp';
+import {ManifestTransform} from '../types';
+
+export function modifyURLPrefixTransform(modifyURLPrefix: {
+  [key: string]: string;
+}): ManifestTransform {
+  if (
+    !modifyURLPrefix ||
+    typeof modifyURLPrefix !== 'object' ||
+    Array.isArray(modifyURLPrefix)
+  ) {
+    throw new Error(errors['modify-url-prefix-bad-prefixes']);
+  }
+
+  // If there are no entries in modifyURLPrefix, just return an identity
+  // function as a shortcut.
+  if (Object.keys(modifyURLPrefix).length === 0) {
+    return (manifest) => {
+      return {manifest};
+    };
+  }
+
+  for (const key of Object.keys(modifyURLPrefix)) {
+    if (typeof modifyURLPrefix[key] !== 'string') {
+      throw new Error(errors['modify-url-prefix-bad-prefixes']);
+    }
+  }
+
+  // Escape the user input so it's safe to use in a regex.
+  const safeModifyURLPrefixes = Object.keys(modifyURLPrefix).map(escapeRegExp);
+  // Join all the `modifyURLPrefix` keys so a single regex can be used.
+  const prefixMatchesStrings = safeModifyURLPrefixes.join('|');
+  // Add `^` to the front the prefix matches so it only matches the start of
+  // a string.
+  const modifyRegex = new RegExp(`^(${prefixMatchesStrings})`);
+
+  return (originalManifest) => {
+    const manifest = originalManifest.map((entry) => {
+      if (typeof entry.url !== 'string') {
+        throw new Error(errors['manifest-entry-bad-url']);
+      }
+
+      entry.url = entry.url.replace(modifyRegex, (match) => {
+        return modifyURLPrefix[match];
+      });
+
+      return entry;
+    });
+
+    return {manifest};
+  };
+}