feat(sdkFetch): 为 get 方法新增 cache 选项，使 url timestamp 可选

src/SDKFetch.ts

@@ -40,6 +40,12 @@ export type SDKFetchOptions = {
    * response headers。默认为 false，仅返回 response body。
    */
   includeHeaders?: boolean
+
+  /**
+   * 当设置为 false 时，将强制浏览器不缓存请求，仅对 GET 类型生效,
+   * 默认为 false
+   */
+  cache?: boolean
 }
 
 export namespace HttpHeaders {
@@ -117,8 +123,11 @@ export class SDKFetch {
 
     if (!SDKFetch.FetchStack.has(urlWithQuery)) {
       const tail = SDKFetch.fetchTail || Date.now()
-      const urlWithTail = appendQueryString(urlWithQuery, `_=${ tail }`)
-      dist = Observable.defer(() => http.setUrl(urlWithTail).get()['request'])
+      let requestUrl = urlWithQuery
+      if (!options.cache) {
+        requestUrl = appendQueryString(urlWithQuery, `_=${ tail }`)
+      }
+      dist = Observable.defer(() => http.setUrl(requestUrl).get()['request'])
         .shareReplay<any>(1)
         .finally(() => {
           SDKFetch.FetchStack.delete(urlWithQuery)

test/SDKFetch.spec.ts

@@ -142,6 +142,51 @@ describe('SDKFetch', () => {
       })
   })
 
+  it('`cache` should effected', function* () {
+    fetchMock.get(urlMatcher, {})
+
+    // 无 query 的 GET
+    yield sdkFetch.get(path, null, { cache: true })
+      .subscribeOn(Scheduler.asap)
+      .do(() => {
+        expect(fetchMock.lastUrl(urlMatcher).indexOf('?_=')).to.equal(-1)
+      })
+
+    // 有 query 的 GET
+    const query = { value: 'A' }
+    yield sdkFetch.get(path, query, { cache: true })
+      .subscribeOn(Scheduler.asap)
+      .do(() => {
+        expect(fetchMock.lastUrl(urlMatcher).indexOf('&_=')).to.equal(-1)
+      })
+  })
+
+  it('`cache` default should be `false`', function* () {
+    fetchMock.get(urlMatcher, {})
+
+    // 无 query 的 GET
+    yield sdkFetch.get(path)
+      .subscribeOn(Scheduler.asap)
+      .do(() => {
+        const delimiter = '?_='
+        const [prefix, timestamp] = fetchMock.lastUrl(urlMatcher).split(delimiter, 2)
+        expect(prefix).to.equal(testUrl)
+        expect(new Date(Number(timestamp)).valueOf()).to.closeTo(new Date().valueOf(), 100)
+      })
+
+    // 带 query 的 GET
+    const query = { value: 'A' }
+    const urlWithQuery = testUrl + '?value=A'
+    yield sdkFetch.get(path, query)
+      .subscribeOn(Scheduler.asap)
+      .do(() => {
+        const delimiter = '&_='
+        const [prefix, timestamp] = fetchMock.lastUrl(urlMatcher).split(delimiter, 2)
+        expect(prefix).to.equal(urlWithQuery)
+        expect(new Date(Number(timestamp)).valueOf()).to.closeTo(new Date().valueOf(), 100)
+      })
+  })
+
   it('get with empty query object should work correctly', function* () {
     fetchMock.get(urlMatcher, {})