Merge pull request #36 from vince-riv/feat/pr-head-check

feat: compare event sha to HEAD

cmd/main.go

@@ -138,7 +138,7 @@ func processEvent(eventInfo webhook.EventInfo) {
 		//println("+++++++++++++")
 		//fmt.Print(cMarkdown.String()[0])
 		//println(".............")
-		_, _ = github.Comment(ctx, eventInfo.RepoOwner, eventInfo.RepoName, eventInfo.PrNum, cMarkdown.String())
+		_, _ = github.Comment(ctx, eventInfo.RepoOwner, eventInfo.RepoName, eventInfo.PrNum, eventInfo.Sha, cMarkdown.String())
 		return
 	}
 }

internal/github/comment.go

@@ -59,6 +59,37 @@ func getCommentUser(ctx context.Context) error {
 	return nil
 }
 
+// Gets the specified pull request
+func GetPullRequest(ctx context.Context, owner, repo string, prNum int) (*github.PullRequest, error) {
+	pr, resp, err := commentClient.PullRequests.Get(ctx, owner, repo, prNum)
+	if resp != nil {
+		log.Info().Msgf("%s received when calling client.Users.Get() via go-github", resp.Status)
+	}
+	if err != nil {
+		log.Error().Err(err).Msgf("Unable to fetch pull request %s/%s#%d", owner, repo, prNum)
+		return nil, err
+	}
+	return pr, nil
+}
+
+// Returns true if sha is HEAD of the pull request
+func isPrHead(ctx context.Context, sha, owner, repo string, prNum int) bool {
+	pr, err := GetPullRequest(ctx, owner, repo, prNum)
+	if err != nil {
+		log.Warn().Msgf("GetPullRequest() err'd - assuming %s is HEAD of %s/%s#%d", sha, owner, repo, prNum)
+		return true
+	}
+	if pr.Head == nil {
+		log.Warn().Msgf("%s/%s#%d has no HEAD - assuming %s is not HEAD", owner, repo, prNum, sha)
+		return false
+	}
+	if pr.Head.SHA == nil {
+		log.Warn().Msgf("SHA for PullRequestBranch of %s/%s#%d is nil - assuming %s is not HEAD", owner, repo, prNum, sha)
+		return false
+	}
+	return sha == *pr.Head.SHA
+}
+
 //func saveResponse(v any, filename string) {
 //	jsonData, err := json.Marshal(v)
 //	if err != nil {
@@ -121,8 +152,12 @@ func getExistingComments(ctx context.Context, owner, repo string, prNum int) ([]
 }
 
 // Creates or updates comment on the specified pull request
-func Comment(ctx context.Context, owner, repo string, prNum int, commentBodies []string) ([]*github.IssueComment, error) {
+func Comment(ctx context.Context, owner, repo string, prNum int, sha string, commentBodies []string) ([]*github.IssueComment, error) {
 	var res []*github.IssueComment
+	if !isPrHead(ctx, sha, owner, repo, prNum) {
+		log.Info().Msgf("%s is not HEAD for %s/%s#%d - skipping comment", sha, owner, repo, prNum)
+		return res, nil
+	}
 	existingComments, err := getExistingComments(ctx, owner, repo, prNum)
 	if err != nil {
 		return res, err

internal/github/comment_test.go

@@ -28,6 +28,9 @@ const payloadPr2CreateComment = "payload-pr-2-create-comment.json"
 
 // const payloadPr3UpdateComment = "payload-pr-3-update-comment.json"
 const payloadPatchComment = "payload-pr-patch-comment.json"
+const payloadPullRequest = "payload-pr-get.json"
+
+const prHeadSha = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 
 func readFileToByteArray(fileName string) ([]byte, string, error) {
 	workingDir, err := os.Getwd()
@@ -65,6 +68,7 @@ func jsonFieldExtract(srcField string, src []byte, destField string, dest []byte
 }
 
 func newHttpTestServer(t *testing.T) *httptest.Server {
+	// TODO - unclutter this mess
 	newServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		statusCode := http.StatusNotFound
 		payload := []byte(`404 Page Not Found`)
@@ -98,6 +102,30 @@ func newHttpTestServer(t *testing.T) *httptest.Server {
 			} else {
 				statusCode = http.StatusMethodNotAllowed
 			}
+		} else if strings.HasPrefix(r.URL.Path, "/repos/vince-riv/argo-diff/pulls/") {
+			if r.Method == "GET" {
+				urlPathParts := strings.Split(r.URL.Path, "/")
+				if urlPathParts[5] == "" {
+					statusCode = http.StatusInternalServerError
+					t.Errorf("Bad URL Path: %s", r.URL.Path)
+				} else {
+					statusCode = http.StatusOK
+					payload, filePath, err = readFileToByteArray(payloadPullRequest)
+					if err != nil {
+						w.WriteHeader(http.StatusInternalServerError)
+						t.Errorf("readFileToByteArray() failed: %s", err)
+						return
+					}
+					payload = bytes.Replace(payload, []byte("%%_PR_NUM_%%"), []byte(urlPathParts[5]), -1)
+					if err != nil {
+						w.WriteHeader(http.StatusInternalServerError)
+						t.Errorf("jsonFieldExtract() failed: %s", err)
+						return
+					}
+				}
+			} else {
+				statusCode = http.StatusMethodNotAllowed
+			}
 		} else {
 			switch r.URL.Path {
 			case "/user":
@@ -159,7 +187,7 @@ func TestCommentNoExistingComments(t *testing.T) {
 		t.Error("Expected no existing comment")
 	}
 
-	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 1, []string{"argo-diff test comment"})
+	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 1, prHeadSha, []string{"argo-diff test comment"})
 	if err != nil {
 		t.Errorf("Comment() failed: %s", err)
 	}
@@ -184,7 +212,7 @@ func TestCommentExistingDifferentUser(t *testing.T) {
 		t.Error("Expected no existing comment")
 	}
 
-	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 2, []string{"argo-diff test comment"})
+	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 2, prHeadSha, []string{"argo-diff test comment"})
 	if err != nil {
 		t.Errorf("Comment() failed: %s", err)
 	}
@@ -211,7 +239,7 @@ func TestCommentExisting(t *testing.T) {
 		t.Error("Comment ID doesn't match")
 	}
 
-	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 3, []string{"argo-diff test comment"})
+	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 3, prHeadSha, []string{"argo-diff test comment"})
 	if err != nil {
 		t.Errorf("Comment() failed: %s", err)
 	}
@@ -238,7 +266,7 @@ func TestCommentExistingMulti(t *testing.T) {
 		t.Error("Unexpected issue commit IDs")
 	}
 
-	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 4, []string{"argo-diff test comment update"})
+	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 4, prHeadSha, []string{"argo-diff test comment update"})
 	if err != nil {
 		t.Errorf("Comment() failed: %s", err)
 	}
@@ -255,3 +283,22 @@ func TestCommentExistingMulti(t *testing.T) {
 		t.Errorf("1st Comment body doesn't match '[Outdated argo-diff content]': %s", *comments[1].Body)
 	}
 }
+
+func TestCommentNotHead(t *testing.T) {
+	server := newHttpTestServer(t)
+	defer server.Close()
+	httpBaseUrl, _ := url.Parse(server.URL + "/")
+	commentClient = github.NewClient(nil).WithAuthToken("test1234")
+	commentClient.BaseURL = httpBaseUrl
+	commentClient.UploadURL = httpBaseUrl
+
+	prHeadShaOld := "1111111111111111111111111111111111111111"
+
+	comments, err := Comment(context.Background(), "vince-riv", "argo-diff", 1, prHeadShaOld, []string{"argo-diff test comment"})
+	if err != nil {
+		t.Errorf("Comment() failed: %s", err)
+	}
+	if len(comments) > 0 {
+		t.Error("Not expecting to comment")
+	}
+}