func UpdatePullRequestBranch()

in pkg/github/pullrequests.go [538:613]
70 lines of code
14 McCabe index (conditional complexity)

func UpdatePullRequestBranch(getClient GetClientFn, t translations.TranslationHelperFunc) (tool mcp.Tool, handler server.ToolHandlerFunc) {
	return mcp.NewTool("update_pull_request_branch",
			mcp.WithDescription(t("TOOL_UPDATE_PULL_REQUEST_BRANCH_DESCRIPTION", "Update the branch of a pull request with the latest changes from the base branch.")),
			mcp.WithToolAnnotation(mcp.ToolAnnotation{
				Title:        t("TOOL_UPDATE_PULL_REQUEST_BRANCH_USER_TITLE", "Update pull request branch"),
				ReadOnlyHint: false,
			}),
			mcp.WithString("owner",
				mcp.Required(),
				mcp.Description("Repository owner"),
			),
			mcp.WithString("repo",
				mcp.Required(),
				mcp.Description("Repository name"),
			),
			mcp.WithNumber("pullNumber",
				mcp.Required(),
				mcp.Description("Pull request number"),
			),
			mcp.WithString("expectedHeadSha",
				mcp.Description("The expected SHA of the pull request's HEAD ref"),
			),
		),
		func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
			owner, err := requiredParam[string](request, "owner")
			if err != nil {
				return mcp.NewToolResultError(err.Error()), nil
			}
			repo, err := requiredParam[string](request, "repo")
			if err != nil {
				return mcp.NewToolResultError(err.Error()), nil
			}
			pullNumber, err := RequiredInt(request, "pullNumber")
			if err != nil {
				return mcp.NewToolResultError(err.Error()), nil
			}
			expectedHeadSHA, err := OptionalParam[string](request, "expectedHeadSha")
			if err != nil {
				return mcp.NewToolResultError(err.Error()), nil
			}
			opts := &github.PullRequestBranchUpdateOptions{}
			if expectedHeadSHA != "" {
				opts.ExpectedHeadSHA = github.Ptr(expectedHeadSHA)
			}

			client, err := getClient(ctx)
			if err != nil {
				return nil, fmt.Errorf("failed to get GitHub client: %w", err)
			}
			result, resp, err := client.PullRequests.UpdateBranch(ctx, owner, repo, pullNumber, opts)
			if err != nil {
				// Check if it's an acceptedError. An acceptedError indicates that the update is in progress,
				// and it's not a real error.
				if resp != nil && resp.StatusCode == http.StatusAccepted && isAcceptedError(err) {
					return mcp.NewToolResultText("Pull request branch update is in progress"), nil
				}
				return nil, fmt.Errorf("failed to update pull request branch: %w", err)
			}
			defer func() { _ = resp.Body.Close() }()

			if resp.StatusCode != http.StatusAccepted {
				body, err := io.ReadAll(resp.Body)
				if err != nil {
					return nil, fmt.Errorf("failed to read response body: %w", err)
				}
				return mcp.NewToolResultError(fmt.Sprintf("failed to update pull request branch: %s", string(body))), nil
			}

			r, err := json.Marshal(result)
			if err != nil {
				return nil, fmt.Errorf("failed to marshal response: %w", err)
			}

			return mcp.NewToolResultText(string(r)), nil
		}
}