Request cacheability follow the spec

Relevant spec part: https://w3c.github.io/ServiceWorker/\#cache-addAll

Author: p-j

packages/service-worker-mock/__tests__/Cache.js

@@ -63,4 +63,28 @@ describe('Cache', () => {
 
     expect(keys.length).toBe(1);
   });
+
+  it('throw when the request is not cacheable', async () => {
+    const cache = new Cache();
+    [
+      'HEAD',
+      'POST',
+      'PUT',
+      'DELETE',
+      'CONNECT',
+      'OPTIONS',
+      'TRACE',
+      'PATCH'
+    ].forEach((method) => {
+      cache.put(new Request('http://example.org', { method })).catch((e) => {
+        expect(e).toEqual(new TypeError(`'${method}' HTTP method is unsupported.`));
+      });
+    });
+
+    expect(async () => {
+      cache.put(new Request('data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7')).catch((e) => {
+        expect(e).toEqual(new TypeError('Request scheme \'data\' is unsupported'));
+      });
+    });
+  });
 });

packages/service-worker-mock/models/Cache.js

@@ -1,4 +1,14 @@
 // https://developer.mozilla.org/en-US/docs/Web/API/Cache
+function validateCacheableRequest(request) {
+  const requestScheme = new URL(request.url).protocol.replace(':', '');
+  if (request.method !== 'GET') {
+    throw new TypeError(`'${request.method}' HTTP method is unsupported.`);
+  }
+  if (!['http', 'https'].includes(requestScheme)) {
+    throw new TypeError(`Request scheme '${requestScheme}' is unsupported`);
+  }
+}
+
 class Cache {
   constructor() {
     this.store = new Map();
@@ -40,6 +50,12 @@ class Cache {
       request = new Request(request);
       // Add relative url as well (non-standard)
       this.store.set(relativeUrl, { request, response });
+    } else {
+      try {
+        validateCacheableRequest(request);
+      } catch (error) {
+        return Promise.reject(error);
+      }
     }
 
     this.store.set(request.url, { request, response });