1 files changed, 63 insertions, 0 deletions
diff --git a/node_modules/workbox-range-requests/utils/parseRangeHeader.mjs b/node_modules/workbox-range-requests/utils/parseRangeHeader.mjs
new file mode 100644
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--- /dev/null
+++ b/node_modules/workbox-range-requests/utils/parseRangeHeader.mjs
@@ -0,0 +1,63 @@
+/*
+  Copyright 2017 Google Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      https://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+import {WorkboxError} from 'workbox-core/_private/WorkboxError.mjs';
+import {assert} from 'workbox-core/_private/assert.mjs';
+
+import '../_version.mjs';
+
+/**
+ * @param {string} rangeHeader A Range: header value.
+ * @return {Object} An object with `start` and `end` properties, reflecting
+ * the parsed value of the Range: header. If either the `start` or `end` are
+ * omitted, then `null` will be returned.
+ *
+ * @private
+ */
+function parseRangeHeader(rangeHeader) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert.isType(rangeHeader, 'string', {
+      moduleName: 'workbox-range-requests',
+      funcName: 'parseRangeHeader',
+      paramName: 'rangeHeader',
+    });
+  }
+
+  const normalizedRangeHeader = rangeHeader.trim().toLowerCase();
+  if (!normalizedRangeHeader.startsWith('bytes=')) {
+    throw new WorkboxError('unit-must-be-bytes', {normalizedRangeHeader});
+  }
+
+  // Specifying multiple ranges separate by commas is valid syntax, but this
+  // library only attempts to handle a single, contiguous sequence of bytes.
+  // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range#Syntax
+  if (normalizedRangeHeader.includes(',')) {
+    throw new WorkboxError('single-range-only', {normalizedRangeHeader});
+  }
+
+  const rangeParts = /(\d*)-(\d*)/.exec(normalizedRangeHeader);
+  // We need either at least one of the start or end values.
+  if (rangeParts === null || !(rangeParts[1] || rangeParts[2])) {
+    throw new WorkboxError('invalid-range-values', {normalizedRangeHeader});
+  }
+
+  return {
+    start: rangeParts[1] === '' ? null : Number(rangeParts[1]),
+    end: rangeParts[2] === '' ? null : Number(rangeParts[2]),
+  };
+}
+
+export {parseRangeHeader};