Allow configuring additional success statuses in HttpStore

Summary:
Changelog:

* **[Feature]** Add `additionalSuccessStatuses` option to `HttpStore`.

Adds a mechanism for specifying HTTP response codes to treat as successful (on top of actual success codes like 200) when reading from/writing to a remote cache server.

It can be useful to tell Metro to ignore certain errors coming from an HTTP cache backend, particularly on write: if the error is, for example, that a concurrent write has happened to the same key, it's conceptually safe to ignore - because we can reasonably assume that the write is coming from another instance of Metro that has the same cache configuration.

Reviewed By: GijsWeterings

Differential Revision: D55752523

fbshipit-source-id: f4953d3151e6d74714690bda9cc43d004db91b79

packages/metro-cache/src/stores/HttpStore.js

@@ -33,6 +33,7 @@ type EndpointOptions = {
   ca?: string | $ReadOnlyArray<string> | Buffer | $ReadOnlyArray<Buffer>,
   params?: URLSearchParams,
   headers?: {[string]: string},
+  additionalSuccessStatuses?: $ReadOnlyArray<number>,
 };
 
 type Endpoint = {
@@ -44,6 +45,7 @@ type Endpoint = {
   params: URLSearchParams,
   headers?: {[string]: string},
   timeout: number,
+  additionalSuccessStatuses: $ReadOnlySet<number>,
 };
 
 const ZLIB_OPTIONS = {
@@ -109,6 +111,9 @@ class HttpStore<T> {
       params: new URLSearchParams(options.params),
       timeout: options.timeout || 5000,
       module: uri.protocol === 'http:' ? http : https,
+      additionalSuccessStatuses: new Set(
+        options.additionalSuccessStatuses ?? [],
+      ),
     };
   }
 
@@ -142,7 +147,10 @@ class HttpStore<T> {
           resolve(null);
 
           return;
-        } else if (code !== 200) {
+        } else if (
+          code !== 200 &&
+          !this._getEndpoint.additionalSuccessStatuses.has(code)
+        ) {
           res.resume();
           reject(new HttpError('HTTP error: ' + code, code));
 
@@ -215,7 +223,10 @@ class HttpStore<T> {
       const req = this._setEndpoint.module.request(options, res => {
         const code = res.statusCode;
 
-        if (code < 200 || code > 299) {
+        if (
+          (code < 200 || code > 299) &&
+          !this._setEndpoint.additionalSuccessStatuses.has(code)
+        ) {
           res.resume();
           reject(new HttpError('HTTP error: ' + code, code));
 

packages/metro-cache/src/stores/__tests__/HttpStore-test.js

@@ -17,9 +17,9 @@ describe('HttpStore', () => {
   let HttpStore;
   let httpPassThrough;
 
-  function responseHttpOk(data) {
+  function responseHttpOk(data, statusCode = 200) {
     const res = Object.assign(new PassThrough(), {
-      statusCode: 200,
+      statusCode,
     });
 
     process.nextTick(() => {
@@ -30,10 +30,16 @@ describe('HttpStore', () => {
     return res;
   }
 
-  function responseHttpError(code) {
-    return Object.assign(new PassThrough(), {
-      statusCode: code,
+  function responseHttpError(statusCode) {
+    const res = Object.assign(new PassThrough(), {
+      statusCode,
+    });
+
+    process.nextTick(() => {
+      res.end();
     });
+
+    return res;
   }
 
   function responseError(err) {
@@ -112,6 +118,25 @@ describe('HttpStore', () => {
     });
   });
 
+  it('get() resolves when the HTTP code is in additionalSuccessStatuses', async () => {
+    const store = new HttpStore({
+      endpoint: 'http://www.example.com/endpoint',
+      additionalSuccessStatuses: [419],
+    });
+    const promise = store.get(Buffer.from('key'));
+    const [opts, callback] = require('http').request.mock.calls[0];
+
+    expect(opts.method).toEqual('GET');
+    expect(opts.host).toEqual('www.example.com');
+    expect(opts.path).toEqual('/endpoint/6b6579');
+    expect(opts.timeout).toEqual(5000);
+
+    callback(responseHttpOk(JSON.stringify({foo: 42}), 419));
+    jest.runAllTimers();
+
+    expect(await promise).toEqual({foo: 42});
+  });
+
   it('rejects when it gets an invalid JSON response', done => {
     const store = new HttpStore({endpoint: 'http://example.com'});
     const promise = store.get(Buffer.from('key'));
@@ -187,6 +212,30 @@ describe('HttpStore', () => {
     });
   });
 
+  test('set() resolves when the HTTP code is in additionalSuccessStatuses', done => {
+    const store = new HttpStore({
+      endpoint: 'http://www.example.com/endpoint',
+      additionalSuccessStatuses: [403],
+    });
+    const promise = store.set(Buffer.from('key-set'), {foo: 42});
+    const [opts, callback] = require('http').request.mock.calls[0];
+
+    expect(opts.method).toEqual('PUT');
+    expect(opts.host).toEqual('www.example.com');
+    expect(opts.path).toEqual('/endpoint/6b65792d736574');
+    expect(opts.timeout).toEqual(5000);
+
+    callback(responseHttpError(403));
+
+    httpPassThrough.on('data', () => {});
+
+    httpPassThrough.on('end', async () => {
+      await promise; // Ensure that the setting promise successfully finishes.
+
+      done();
+    });
+  });
+
   it('rejects when setting and HTTP returns an error response', done => {
     const store = new HttpStore({endpoint: 'http://example.com'});
     const promise = store.set(Buffer.from('key-set'), {foo: 42});