add code suggestion function

atlasaction/action.go

@@ -145,6 +145,9 @@ func MigrateLint(ctx context.Context, client *atlasexec.Client, act *githubactio
 	if err := addChecks(act, &payload); err != nil {
 		return err
 	}
+	if err := addSuggestions(act, &payload); err != nil {
+		return err
+	}
 	if errors.Is(err, atlasexec.LintErr) {
 		return fmt.Errorf("lint completed with errors, see report: %s", payload.URL)
 	}
@@ -258,12 +261,65 @@ func addChecks(act *githubactions.Action, payload *atlasexec.SummaryReport) erro
 	return nil
 }
 
+// addSuggestions comments on the pull request for the given payload.
+func addSuggestions(act *githubactions.Action, payload *atlasexec.SummaryReport) error {
+	ghContext, err := act.Context()
+	if err != nil {
+		return err
+	}
+	event, err := triggerEvent(ghContext)
+	if err != nil {
+		return err
+	}
+	ghClient := githubAPI{
+		baseURL: ghContext.APIURL,
+		client: &http.Client{
+			Transport: &roundTripper{
+				authToken: act.Getenv("GITHUB_TOKEN"),
+			},
+			Timeout: time.Second * 30,
+		},
+	}
+	for _, file := range payload.Files {
+		filePath := path.Join(payload.Env.Dir, file.Name)
+		for _, report := range file.Reports {
+			for _, s := range report.SuggestedFixes {
+				prComment := pullRequestComment{
+					Body:      s.Message,
+					Path:      filePath,
+					CommitID:  ghContext.SHA,
+					StartLine: 1,
+					Line:      1,
+				}
+				buf, err := json.Marshal(prComment)
+				if err != nil {
+					return err
+				}
+				r := bytes.NewReader(buf)
+				if err := ghClient.createPullRequestComment(event.PullRequestNumber, r, ghContext.Repository); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
 type (
 	githubIssueComment struct {
 		ID   int    `json:"id"`
 		Body string `json:"body"`
 	}
 
+	pullRequestComment struct {
+		Body      string `json:"body"`
+		Path      string `json:"path"`
+		CommitID  string `json:"commit_id"`
+		StartLine int    `json:"start_line"`
+		Line      int    `json:"line"`
+		StartSide string `json:"start_side" default:"RIGHT"`
+	}
+
 	githubAPI struct {
 		baseURL string
 		client  *http.Client
@@ -350,6 +406,26 @@ func (g *githubAPI) updateComment(id int, content io.Reader, repo string) error
 	return err
 }
 
+func (g *githubAPI) createPullRequestComment(id int, content io.Reader, repo string) error {
+	url := fmt.Sprintf("%v/repos/%v/pulls/%v/comments", g.baseURL, repo, id)
+	req, err := http.NewRequest(http.MethodPost, url, content)
+	if err != nil {
+		return err
+	}
+	res, err := g.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusCreated {
+		b, err := io.ReadAll(res.Body)
+		if err != nil {
+			return fmt.Errorf("unexpected status code %v: unable to read body %v", res.StatusCode, err)
+		}
+		return fmt.Errorf("unexpected status code %v: with body: %v", res.StatusCode, string(b))
+	}
+	return err
+}
 
 func createRunContext(act *githubactions.Action) (*atlasexec.RunContext, error) {
 	ghContext, err := act.Context()