fetch comment by ID

Author: shuyama1

.ci/magician/cmd/interfaces.go

@@ -27,6 +27,7 @@ type GithubClient interface {
 	GetPullRequestRequestedReviewers(prNumber string) ([]github.User, error)
 	GetPullRequestPreviousReviewers(prNumber string) ([]github.User, error)
 	GetPullRequestComments(prNumber string) ([]github.PullRequestComment, error)
+	GetPullRequestComment(commentID int) (github.PullRequestComment, error)
 	GetCommitMessage(owner, repo, sha string) (string, error)
 	GetUserType(user string) github.UserType
 	GetTeamMembers(organization, team string) ([]github.User, error)

.ci/magician/cmd/mock_github_test.go

@@ -17,6 +17,7 @@ package cmd
 
 import (
 	"errors"
+	"fmt"
 
 	"magician/github"
 )
@@ -62,6 +63,16 @@ func (m *mockGithub) GetPullRequestComments(prNumber string) ([]github.PullReque
 	return m.pullRequestComments, nil
 }
 
+func (m *mockGithub) GetPullRequestComment(commentID int) (github.PullRequestComment, error) {
+	m.calledMethods["GetPullRequestComment"] = append(m.calledMethods["GetPullRequestComment"], []any{commentID})
+	for _, c := range m.pullRequestComments {
+		if c.ID == commentID {
+			return c, nil
+		}
+	}
+	return github.PullRequestComment{}, fmt.Errorf("comment not found")
+}
+
 func (m *mockGithub) GetCommitMessage(owner, repo, sha string) (string, error) {
 	m.calledMethods["GetCommitMessage"] = append(m.calledMethods["GetCommitMessage"], []any{owner, repo, sha})
 	return m.commitMessage, nil

.ci/magician/cmd/test_terraform_vcr.go

@@ -512,22 +512,19 @@ View the [build log](https://storage.cloud.google.com/ci-vcr-logs/beta/refs/head
 	return false, nil
 }
 
+// appendVCRResultToDiffComment appends content to the existing diff report comment
+// identified by the ID in /workspace/diff_comment_id.txt.
+// If the file is missing or the comment cannot be fetched, it falls back to posting a new comment.
 func appendVCRResultToDiffComment(prNumber string, content string, gh GithubClient, rnr ExecRunner) error {
-	comments, err := gh.GetPullRequestComments(prNumber)
-	if err != nil {
-		return fmt.Errorf("error getting PR comments: %w", err)
-	}
-
 	var diffComment *github.PullRequestComment
 
 	// Try to find by ID from file
 	if idStr, err := rnr.ReadFile("/workspace/diff_comment_id.txt"); err == nil {
 		if id, err := strconv.Atoi(strings.TrimSpace(idStr)); err == nil {
-			for _, c := range comments {
-				if c.ID == id {
-					diffComment = &c
-					break
-				}
+			if comment, err := gh.GetPullRequestComment(id); err == nil {
+				diffComment = &comment
+			} else {
+				fmt.Printf("Warning: failed to fetch comment %d by ID: %v\n", id, err)
 			}
 		}
 	}
@@ -538,7 +535,7 @@ func appendVCRResultToDiffComment(prNumber string, content string, gh GithubClie
 	}
 
 	// Fallback to posting a new comment if diff report not found
-	_, err = gh.PostComment(prNumber, content)
+	_, err := gh.PostComment(prNumber, content)
 	return err
 }
 

.ci/magician/github/get.go

@@ -184,6 +184,15 @@ func (c *Client) GetPullRequestComments(prNumber string) ([]PullRequestComment,
 	return convertGHComments(allComments), nil
 }
 
+// GetPullRequestComment fetches a single comment by ID
+func (c *Client) GetPullRequestComment(commentID int) (PullRequestComment, error) {
+	comment, _, err := c.gh.Issues.GetComment(c.ctx, defaultOwner, defaultRepo, int64(commentID))
+	if err != nil {
+		return PullRequestComment{}, err
+	}
+	return convertGHComment(comment), nil
+}
+
 // GetTeamMembers gets all members of a team, handling pagination
 func (c *Client) GetTeamMembers(organization, team string) ([]User, error) {
 	var allMembers []*gh.User