backend: add ListPullRequestsWithCommit into Github APIs

backend/mock/service/githubmock/githubmock.go

@@ -63,6 +63,10 @@ func (s svc) ListOrganizations(ctx context.Context, user string) ([]*githubv3.Or
 	}, nil
 }
 
+func (s svc) ListPullRequestsWithCommit(ctx context.Context, ref *github.RemoteRef, sha string) ([]*github.PullRequestInfo, error) {
+	panic("implement me")
+}
+
 func (s svc) GetOrgMembership(ctx context.Context, user, org string) (*githubv3.Membership, error) {
 	role := "member"
 	return &githubv3.Membership{Role: &role}, nil

backend/service/github/github.go

@@ -103,6 +103,7 @@ type Client interface {
 	GetRepository(ctx context.Context, ref *RemoteRef) (*Repository, error)
 	GetOrganization(ctx context.Context, organization string) (*githubv3.Organization, error)
 	ListOrganizations(ctx context.Context, user string) ([]*githubv3.Organization, error)
+	ListPullRequestsWithCommit(ctx context.Context, ref *RemoteRef, sha string) ([]*PullRequestInfo, error)
 	GetOrgMembership(ctx context.Context, user, org string) (*githubv3.Membership, error)
 	GetUser(ctx context.Context, username string) (*githubv3.User, error)
 }
@@ -117,8 +118,9 @@ func (s *svc) CreateIssueComment(ctx context.Context, ref *RemoteRef, number int
 }
 
 type PullRequestInfo struct {
-	Number  int
-	HTMLURL string
+	Number     int
+	HTMLURL    string
+	BranchName string
 }
 
 type svc struct {
@@ -216,6 +218,10 @@ func boolPtr(b bool) *bool {
 	return &b
 }
 
+func intPtr(i int) *int {
+	return &i
+}
+
 func (s *svc) CreatePullRequest(ctx context.Context, ref *RemoteRef, base, title, body string) (*PullRequestInfo, error) {
 	req := &githubv3.NewPullRequest{
 		Title:               strPtr(title),
@@ -236,6 +242,25 @@ func (s *svc) CreatePullRequest(ctx context.Context, ref *RemoteRef, base, title
 	}, nil
 }
 
+func (s *svc) ListPullRequestsWithCommit(ctx context.Context, ref *RemoteRef, sha string) ([]*PullRequestInfo, error) {
+	// PullRequestListOptions left as nil since default opts are sufficient (State: "open", Sort: "created")
+	respPRs, _, err := s.rest.PullRequests.ListPullRequestsWithCommit(ctx, ref.RepoOwner, ref.RepoName, sha, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	prInfos := make([]*PullRequestInfo, len(respPRs))
+	for i, pr := range respPRs {
+		prInfos[i] = &PullRequestInfo{
+			Number:     pr.GetNumber(),
+			HTMLURL:    pr.GetHTMLURL(),
+			BranchName: pr.GetHead().GetRef(),
+		}
+	}
+
+	return prInfos, nil
+}
+
 type CreateBranchRequest struct {
 	// The base for the new branch.
 	Ref *RemoteRef

backend/service/github/github_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"strconv"
 	"testing"
 	"time"
 
@@ -672,3 +673,106 @@ func TestGetRepository(t *testing.T) {
 		})
 	}
 }
+
+type mockPullRequests struct {
+	generalError bool
+
+	actualNumber     int
+	actualHTMLURL    string
+	actualBranchName string
+}
+
+// Dummy mock of Create API so mockPullRequests implements v3pullrequests
+func (m *mockPullRequests) Create(ctx context.Context, owner string, repo string, pull *githubv3.NewPullRequest) (*githubv3.PullRequest, *githubv3.Response, error) {
+	return &githubv3.PullRequest{}, &githubv3.Response{}, nil
+}
+
+// Mock of ListPullRequestsWithCommit API
+func (m *mockPullRequests) ListPullRequestsWithCommit(ctx context.Context, owner, repo, sha string, opts *githubv3.PullRequestListOptions) ([]*githubv3.PullRequest, *githubv3.Response, error) {
+	if m.generalError {
+		return nil, nil, errors.New(problem)
+	}
+
+	m.actualNumber = 1347
+	m.actualHTMLURL = fmt.Sprintf("https://github.com/%s/%s/pull/%s", owner, repo, strconv.Itoa(m.actualNumber))
+	m.actualBranchName = "my-branch"
+
+	return []*githubv3.PullRequest{
+		{
+			Number:  intPtr(m.actualNumber),
+			State:   strPtr("open"),
+			HTMLURL: strPtr(m.actualHTMLURL),
+			Head: &githubv3.PullRequestBranch{
+				Ref: strPtr(m.actualBranchName),
+				SHA: strPtr(sha),
+				Repo: &githubv3.Repository{
+					Name: strPtr(repo),
+				},
+				User: &githubv3.User{
+					Login: strPtr("octocat"),
+				},
+			},
+		},
+	}, nil, nil
+}
+
+var listPullRequestsWithCommitTests = []struct {
+	name        string
+	errorText   string
+	mockPullReq *mockPullRequests
+	repoOwner   string
+	repoName    string
+	ref         string
+	sha         string
+}{
+	{
+		name:        "v3 client error",
+		mockPullReq: &mockPullRequests{generalError: true},
+		errorText:   "we've had a problem",
+		repoOwner:   "my-org",
+		repoName:    "my-repo",
+		ref:         "my-branch",
+		sha:         "asdf12345",
+	},
+	{
+		name:        "happy path",
+		mockPullReq: &mockPullRequests{},
+		repoOwner:   "my-org",
+		repoName:    "my-repo",
+		ref:         "my-branch",
+		sha:         "asdf12345",
+	},
+}
+
+func TestListPullRequestsWithCommit(t *testing.T) {
+	for _, tt := range listPullRequestsWithCommitTests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			s := &svc{rest: v3client{
+				PullRequests: tt.mockPullReq,
+			}}
+
+			resp, err := s.ListPullRequestsWithCommit(
+				context.Background(),
+				&RemoteRef{
+					RepoOwner: tt.repoOwner,
+					RepoName:  tt.repoName,
+					Ref:       tt.ref,
+				},
+				tt.sha)
+
+			if tt.errorText != "" {
+				assert.Error(t, err)
+				assert.Contains(t, err.Error(), tt.errorText)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, 1, len(resp))
+				assert.Equal(t, tt.mockPullReq.actualNumber, resp[0].Number)
+				assert.Equal(t, tt.mockPullReq.actualHTMLURL, resp[0].HTMLURL)
+				assert.Equal(t, tt.mockPullReq.actualBranchName, resp[0].BranchName)
+			}
+		})
+	}
+}

backend/service/github/iface.go

@@ -33,6 +33,8 @@ type v3repositories interface {
 type v3pullrequests interface {
 	// Create a new pull request on the specified repository.
 	Create(ctx context.Context, owner string, repo string, pull *githubv3.NewPullRequest) (*githubv3.PullRequest, *githubv3.Response, error)
+	// ListPullRequestsWithCommit returns pull requests associated with a commit SHA.
+	ListPullRequestsWithCommit(ctx context.Context, owner, repo, sha string, opts *githubv3.PullRequestListOptions) ([]*githubv3.PullRequest, *githubv3.Response, error)
 }
 
 type v4client interface {