Merge pull request #4460 from m4ver1k/feat/2720

#2720 | Add patch flag to pull-request diff command

api/queries_pr.go

@@ -2,9 +2,7 @@ package api
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -267,30 +265,6 @@ func (pr *PullRequest) DisplayableReviews() PullRequestReviews {
 	return PullRequestReviews{Nodes: published, TotalCount: len(published)}
 }
 
-func (c Client) PullRequestDiff(baseRepo ghrepo.Interface, prNumber int) (io.ReadCloser, error) {
-	url := fmt.Sprintf("%srepos/%s/pulls/%d",
-		ghinstance.RESTPrefix(baseRepo.RepoHost()), ghrepo.FullName(baseRepo), prNumber)
-	req, err := http.NewRequest("GET", url, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	req.Header.Set("Accept", "application/vnd.github.v3.diff; charset=utf-8")
-
-	resp, err := c.http.Do(req)
-	if err != nil {
-		return nil, err
-	}
-
-	if resp.StatusCode == 404 {
-		return nil, errors.New("pull request not found")
-	} else if resp.StatusCode != 200 {
-		return nil, HandleHTTPError(resp)
-	}
-
-	return resp.Body, nil
-}
-
 type pullRequestFeature struct {
 	HasReviewDecision       bool
 	HasStatusCheckRollup    bool

pkg/cmd/pr/diff/diff.go

@@ -11,6 +11,8 @@ import (
 
 	"github.com/MakeNowJust/heredoc"
 	"github.com/cli/cli/v2/api"
+	"github.com/cli/cli/v2/internal/ghinstance"
+	"github.com/cli/cli/v2/internal/ghrepo"
 	"github.com/cli/cli/v2/pkg/cmd/pr/shared"
 	"github.com/cli/cli/v2/pkg/cmdutil"
 	"github.com/cli/cli/v2/pkg/iostreams"
@@ -25,6 +27,7 @@ type DiffOptions struct {
 
 	SelectorArg string
 	UseColor    string
+	Patch       bool
 }
 
 func NewCmdDiff(f *cmdutil.Factory, runF func(*DiffOptions) error) *cobra.Command {
@@ -70,6 +73,7 @@ func NewCmdDiff(f *cmdutil.Factory, runF func(*DiffOptions) error) *cobra.Comman
 	}
 
 	cmd.Flags().StringVar(&opts.UseColor, "color", "auto", "Use color in diff output: {always|never|auto}")
+	cmd.Flags().BoolVar(&opts.Patch, "patch", false, "Display diff in patch format")
 
 	return cmd
 }
@@ -88,9 +92,8 @@ func diffRun(opts *DiffOptions) error {
 	if err != nil {
 		return err
 	}
-	apiClient := api.NewClientFromHTTP(httpClient)
 
-	diff, err := apiClient.PullRequestDiff(baseRepo, pr.Number)
+	diff, err := fetchDiff(httpClient, baseRepo, pr.Number, opts.Patch)
 	if err != nil {
 		return fmt.Errorf("could not find pull request diff: %w", err)
 	}
@@ -132,6 +135,36 @@ func diffRun(opts *DiffOptions) error {
 	return nil
 }
 
+func fetchDiff(httpClient *http.Client, baseRepo ghrepo.Interface, prNumber int, asPatch bool) (io.ReadCloser, error) {
+	url := fmt.Sprintf(
+		"%srepos/%s/pulls/%d",
+		ghinstance.RESTPrefix(baseRepo.RepoHost()),
+		ghrepo.FullName(baseRepo),
+		prNumber,
+	)
+	acceptType := "application/vnd.github.v3.diff"
+	if asPatch {
+		acceptType = "application/vnd.github.v3.patch"
+	}
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Accept", acceptType)
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != 200 {
+		return nil, api.HandleHTTPError(resp)
+	}
+
+	return resp.Body, nil
+}
+
 var diffHeaderPrefixes = []string{"+++", "---", "diff", "index"}
 
 func isHeaderLine(dl string) bool {

pkg/cmd/pr/diff/diff_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"io/ioutil"
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/cli/cli/v2/api"
@@ -140,26 +141,67 @@ func runCommand(rt http.RoundTripper, remotes context.Remotes, isTTY bool, cli s
 	}, err
 }
 
-func TestPRDiff_notty(t *testing.T) {
-	http := &httpmock.Registry{}
-	defer http.Verify(t)
+func TestPRDiff_notty_diff(t *testing.T) {
+	httpReg := &httpmock.Registry{}
+	defer httpReg.Verify(t)
 
 	shared.RunCommandFinder("", &api.PullRequest{Number: 123}, ghrepo.New("OWNER", "REPO"))
 
-	http.Register(
+	var gotAccept string
+	httpReg.Register(
 		httpmock.REST("GET", "repos/OWNER/REPO/pulls/123"),
-		httpmock.StringResponse(testDiff))
+		func(req *http.Request) (*http.Response, error) {
+			gotAccept = req.Header.Get("Accept")
+			return &http.Response{
+				StatusCode: 200,
+				Request:    req,
+				Body:       ioutil.NopCloser(strings.NewReader(testDiff)),
+			}, nil
+		})
 
-	output, err := runCommand(http, nil, false, "")
+	output, err := runCommand(httpReg, nil, false, "")
 	if err != nil {
 		t.Fatalf("unexpected error: %s", err)
 	}
 	if diff := cmp.Diff(testDiff, output.String()); diff != "" {
 		t.Errorf("command output did not match:\n%s", diff)
 	}
+	if gotAccept != "application/vnd.github.v3.diff" {
+		t.Errorf("unexpected Accept header: %s", gotAccept)
+	}
 }
 
-func TestPRDiff_tty(t *testing.T) {
+func TestPRDiff_notty_patch(t *testing.T) {
+	httpReg := &httpmock.Registry{}
+	defer httpReg.Verify(t)
+
+	shared.RunCommandFinder("", &api.PullRequest{Number: 123}, ghrepo.New("OWNER", "REPO"))
+
+	var gotAccept string
+	httpReg.Register(
+		httpmock.REST("GET", "repos/OWNER/REPO/pulls/123"),
+		func(req *http.Request) (*http.Response, error) {
+			gotAccept = req.Header.Get("Accept")
+			return &http.Response{
+				StatusCode: 200,
+				Request:    req,
+				Body:       ioutil.NopCloser(strings.NewReader(testDiff)),
+			}, nil
+		})
+
+	output, err := runCommand(httpReg, nil, false, "--patch")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+	if diff := cmp.Diff(testDiff, output.String()); diff != "" {
+		t.Errorf("command output did not match:\n%s", diff)
+	}
+	if gotAccept != "application/vnd.github.v3.patch" {
+		t.Errorf("unexpected Accept header: %s", gotAccept)
+	}
+}
+
+func TestPRDiff_tty_diff(t *testing.T) {
 	http := &httpmock.Registry{}
 	defer http.Verify(t)