Merge pull request #20 from Fallenstedt/0.3.2

0.3.2

VERSION

@@ -1 +1 @@
-0.3.1
+0.3.2

example/go.mod

@@ -2,6 +2,6 @@ module github.com/fallenstedt/twitter-stream/example
 
 replace github.com/fallenstedt/twitter-stream => /Users/alex/Projects/twitter-stream/
 
-go 1.15
+go 1.16
 
 require github.com/fallenstedt/twitter-stream v0.2.1

go.mod

@@ -1,3 +1,3 @@
 module github.com/fallenstedt/twitter-stream
 
-go 1.15
+go 1.16

httpclient/http_client_mock.go

@@ -0,0 +1,36 @@
+package httpclient
+
+import "net/http"
+
+type mockHttpClient struct {
+	token               string
+	MockNewHttpRequest  func(opts *RequestOpts) (*http.Response, error)
+	MockGetSearchStream func(queryParams string) (*http.Response, error)
+	MockGetRules        func() (*http.Response, error)
+	MockAddRules        func(queryParams string, body string) (*http.Response, error)
+	MockGenerateUrl     func(name string, queryParams string) (string, error)
+}
+
+func NewHttpClientMock(token string) *mockHttpClient {
+	return &mockHttpClient{token: token}
+}
+
+func (t *mockHttpClient) GenerateUrl(name string, queryParams string) (string, error) {
+	return t.MockGenerateUrl(name, queryParams)
+}
+
+func (t *mockHttpClient) GetRules() (*http.Response, error) {
+	return t.MockGetRules()
+}
+
+func (t *mockHttpClient) AddRules(queryParams string, body string) (*http.Response, error) {
+	return t.MockAddRules(queryParams, body)
+}
+
+func (t *mockHttpClient) GetSearchStream(queryParams string) (*http.Response, error) {
+	return t.MockGetSearchStream(queryParams)
+}
+
+func (t *mockHttpClient) NewHttpRequest(opts *RequestOpts) (*http.Response, error) {
+	return t.MockNewHttpRequest(opts)
+}

httpclient/http_response_parser.go

@@ -0,0 +1,55 @@
+package httpclient
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"math"
+	"net/http"
+	"time"
+)
+
+// httpResponseParser is a struct that will retry network requests if the response has a status code of 429.
+type httpResponseParser struct{}
+
+func (h httpResponseParser) handleResponse(resp *http.Response, opts *RequestOpts, fn func(opts *RequestOpts) (*http.Response, error)) (*http.Response, error) {
+	// Retry with backoff if 429
+	if resp.StatusCode == 429 {
+		log.Printf("Retrying network request %s with backoff", opts.Url)
+
+		delay := h.getBackOffTime(opts.Retries)
+		log.Printf("Sleeping for %v seconds", delay)
+		time.Sleep(delay)
+
+		opts.Retries += 1
+
+		return fn(opts)
+	}
+
+	// Reject if 400 or greater
+	if resp.StatusCode >= 400 {
+		log.Printf("Network Request at %s failed: %v", opts.Url, resp.StatusCode)
+
+		var msg string
+		if resp.Body != nil {
+			body, _ := ioutil.ReadAll(resp.Body)
+			msg = "Network request failed: " + string(body)
+		} else {
+			msg = "Network request failed with status" + fmt.Sprint(resp.StatusCode)
+		}
+
+		return nil, errors.New(msg)
+	}
+
+	return resp, nil
+}
+
+func (h httpResponseParser) getBackOffTime(retries uint8) time.Duration {
+	exponentialBackoffCeilingSecs := 30
+	delaySecs := int(math.Floor((math.Pow(2, float64(retries)) - 1) * 0.5))
+	if delaySecs > exponentialBackoffCeilingSecs {
+		delaySecs = 30
+	}
+	return time.Duration(delaySecs) * time.Second
+}

httpclient/http_response_parser_test.go

@@ -0,0 +1,70 @@
+package httpclient
+
+import (
+	"net/http"
+	"testing"
+)
+
+func givenHttpResponseParserInstance() *httpResponseParser {
+	return new(httpResponseParser)
+}
+
+func givenFakeHttpResponse(statusCode int) *http.Response {
+	res := new(http.Response)
+	res.StatusCode = statusCode
+	return res
+}
+
+func TestHandleResponseShouldReturnIf200(t *testing.T) {
+	instance := givenHttpResponseParserInstance()
+	opts := new(RequestOpts)
+	resp := givenFakeHttpResponse(200)
+
+	result, err := instance.handleResponse(resp, opts, func(o *RequestOpts) (*http.Response, error) {
+		return nil, nil
+	})
+
+	if err != nil {
+		t.Errorf("Expected not error, got %v", err)
+	}
+
+	if result.StatusCode != 200 {
+		t.Errorf("Expected a status code of 200")
+	}
+}
+
+func TestHandleResponseShouldRetryRequestIf429(t *testing.T) {
+	instance := givenHttpResponseParserInstance()
+	opts := new(RequestOpts)
+	resp := givenFakeHttpResponse(429)
+
+	result, err := instance.handleResponse(resp, opts, func(o *RequestOpts) (*http.Response, error) {
+		return givenFakeHttpResponse(200), nil
+	})
+
+	if opts.Retries != 1 {
+		t.Errorf("Expected atleast on retry attempt, got %v", opts.Retries)
+	}
+
+	if err != nil {
+		t.Errorf("Expected not error, got %v", err)
+	}
+
+	if result.StatusCode != 200 {
+		t.Errorf("Expected a status code of 200")
+	}
+}
+
+func TestHandleResponseShouldRejectIf400OrHigher(t *testing.T) {
+	instance := givenHttpResponseParserInstance()
+	opts := new(RequestOpts)
+	resp := givenFakeHttpResponse(401)
+
+	_, err := instance.handleResponse(resp, opts, func(o *RequestOpts) (*http.Response, error) {
+		return nil, nil
+	})
+
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}