feat(fetchye): http headers casing does not affect cache key creation (#53)

Author: Jimchapter

packages/fetchye/__tests__/computeKey.spec.js

@@ -43,4 +43,19 @@ describe('computeKey', () => {
   it('should return false if key func returns false', () => {
     expect(computeKey(() => false, {})).toEqual(false);
   });
+  it('should return the same hash value irrespective of header name casings', () => {
+    const firstOptions = {
+      headers: {
+        Authorization: 'fake.jw.t',
+        'Content-Type': 'application/json',
+      },
+    };
+    const secondOptions = {
+      headers: {
+        AUTHoriZation: 'fake.jw.t',
+        'content-type': 'application/json',
+      },
+    };
+    expect(computeKey('uri', firstOptions).hash).toBe(computeKey('uri', secondOptions).hash);
+  });
 });

packages/fetchye/src/computeKey.js

@@ -15,21 +15,28 @@
  */
 
 import computeHash from 'object-hash';
+import mapHeaderNamesToLowerCase from './mapHeaderNamesToLowerCase';
 
 export const computeKey = (key, options) => {
+  const { headers, ...restOfOptions } = options;
+  const nextOptions = { ...restOfOptions };
+  if (headers) {
+    nextOptions.headers = mapHeaderNamesToLowerCase(headers);
+  }
+
   if (typeof key === 'function') {
     let nextKey;
     try {
-      nextKey = key(options);
+      nextKey = key(nextOptions);
     } catch (error) {
       return false;
     }
     if (!nextKey) {
       return false;
     }
-    return { key: nextKey, hash: computeHash([nextKey, options], { respectType: false }) };
+    return { key: nextKey, hash: computeHash([nextKey, nextOptions], { respectType: false }) };
   }
-  return { key, hash: computeHash([key, options], { respectType: false }) };
+  return { key, hash: computeHash([key, nextOptions], { respectType: false }) };
 };
 
 export default computeKey;

packages/fetchye/src/mapHeaderNamesToLowerCase.js

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2021 American Express Travel Related Services Company, 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
+ *
+ * http://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.
+ */
+
+const mapHeaderNamesToLowerCase = (headers) => Object.entries(headers)
+  .reduce((lowerCaseHeaders, [headerName, value]) => ({
+    ...lowerCaseHeaders,
+    [headerName.toLowerCase()]: value,
+  }), {});
+
+export default mapHeaderNamesToLowerCase;