Add function for PullRequestService to download raw content of pull request

Author: huydx

.gitignore

@@ -1 +1,2 @@
 *.test
+.idea

github/github.go

@@ -42,6 +42,8 @@ const (
 	mediaTypeV3                = "application/vnd.github.v3+json"
 	defaultMediaType           = "application/octet-stream"
 	mediaTypeV3SHA             = "application/vnd.github.v3.sha"
+	mediaTypeV3Diff 	   = "application/vnd.github.v3.diff"
+	mediaTypeV3Patch           = "application/vnd.github.v3.patch"
 	mediaTypeOrgPermissionRepo = "application/vnd.github.v3.repository+json"
 
 	// Media Type values to access preview APIs
@@ -154,6 +156,19 @@ type UploadOptions struct {
 	Name string `url:"name,omitempty"`
 }
 
+// MediaRawType represents raw return of a request instead of json format
+type MediaRawType int
+
+const (
+	Diff MediaRawType = 1 + iota
+	Patch
+)
+
+// GetRawOptions specifies the optional parameter when user want to get raw presentation of a response instead of json format
+type GetRawOptions struct {
+	Type MediaRawType
+}
+
 // addOptions adds the parameters in opt as URL query parameters to s.  opt
 // must be a struct whose fields may contain "url" tags.
 func addOptions(s string, opt interface{}) (string, error) {

github/pulls.go

@@ -6,6 +6,7 @@
 package github
 
 import (
+	"bytes"
 	"fmt"
 	"time"
 )
@@ -134,6 +135,29 @@ func (s *PullRequestsService) Get(owner string, repo string, number int) (*PullR
 	return pull, resp, err
 }
 
+// GetRaw gets raw (diff or patch) format of a pull request.
+func (s *PullRequestsService) GetRaw(owner string, repo string, number int, opt GetRawOptions) ([]byte, *Response, error) {
+	u := fmt.Sprintf("repos/%v/%v/pulls/%d", owner, repo, number)
+	req, err := s.client.NewRequest("GET", u, nil)
+	if err != nil {
+		return []byte{}, nil, err
+	}
+
+	if opt.Type == Diff {
+		req.Header.Set("Accept", mediaTypeV3Diff)
+	} else if opt.Type == Patch {
+		req.Header.Set("Accept", mediaTypeV3Patch)
+	}
+
+	ret := new(bytes.Buffer)
+	resp, err := s.client.Do(req, ret)
+	if err != nil {
+		return []byte{}, resp, err
+	}
+
+	return ret.Bytes(), resp, err
+}
+
 // NewPullRequest represents a new pull request to be created.
 type NewPullRequest struct {
 	Title *string `json:"title,omitempty"`

github/pulls_test.go

@@ -67,6 +67,48 @@ func TestPullRequestsService_Get(t *testing.T) {
 	}
 }
 
+func TestPullRequestService_GetRawPatch(t *testing.T) {
+	setup()
+	defer teardown()
+	var rawStr = "@@patch content"
+
+	mux.HandleFunc("/repos/o/r/pulls/1", func(w http.ResponseWriter, r *http.Request) {
+		testMethod(t, r, "GET")
+		testHeader(t, r, "Accept", mediaTypeV3Patch)
+		fmt.Fprint(w, rawStr)
+	})
+
+	ret, _, err := client.PullRequests.GetRaw("o", "r", 1, GetRawOptions{Patch})
+	if err != nil {
+		t.Errorf("PullRequests.GetRaw return error: %v", err)
+	}
+
+	if string(ret) != rawStr {
+		t.Errorf("PullRequests.GetRaw returned %s want %s", ret, rawStr)
+	}
+}
+
+func TestPullRequestService_GetRawDiff(t *testing.T) {
+	setup()
+	defer teardown()
+	var rawStr = "@@diff content"
+
+	mux.HandleFunc("/repos/o/r/pulls/1", func(w http.ResponseWriter, r *http.Request) {
+		testMethod(t, r, "GET")
+		testHeader(t, r, "Accept", mediaTypeV3Diff)
+		fmt.Fprint(w, rawStr)
+	})
+
+	ret, _, err := client.PullRequests.GetRaw("o", "r", 1, GetRawOptions{Diff})
+	if err != nil {
+		t.Errorf("PullRequests.GetRaw return error: %v", err)
+	}
+
+	if string(ret) != rawStr {
+		t.Errorf("PullRequests.GetRaw returned %s want %s", ret, rawStr)
+	}
+}
+
 func TestPullRequestsService_Get_headAndBase(t *testing.T) {
 	setup()
 	defer teardown()