feat: implement error notification as pr comment (#124)

* feat: implement error notification as pr comment

* Update action.yml

Co-authored-by: Earl Warren <109468362+earl-warren@users.noreply.github.com>

* feat: implement gitlab client and surround with try catch

* docs: add error notification enablment in the doc

* feat: disable comment if dry-run

* feat: update the default comment on error

---------

Co-authored-by: Earl Warren <109468362+earl-warren@users.noreply.github.com>

src/service/args/args-parser.ts

@@ -48,7 +48,8 @@ export default abstract class ArgsParser {
       strategy: this.getOrDefault(args.strategy),
       strategyOption: this.getOrDefault(args.strategyOption),
       cherryPickOptions: this.getOrDefault(args.cherryPickOptions),
-      comments: this.getOrDefault(args.comments)
+      comments: this.getOrDefault(args.comments),
+      enableErrorNotification: this.getOrDefault(args.enableErrorNotification, false),
     };
   }
 }

src/service/args/args-utils.ts

@@ -50,7 +50,7 @@ export function getAsSemicolonSeparatedList(value: string): string[] | undefined
   return trimmed !== "" ? trimmed.split(";").map(v => v.trim()) : undefined; 
 }
 
-export function getAsBooleanOrDefault(value: string): boolean | undefined {
+export function getAsBooleanOrUndefined(value: string): boolean | undefined {
   const trimmed = value.trim();
   return trimmed !== "" ? trimmed.toLowerCase() === "true" : undefined;
 }

src/service/args/args.types.ts

@@ -28,4 +28,5 @@ export interface Args {
   strategyOption?: string, // cherry-pick merge strategy option
   cherryPickOptions?: string, // additional cherry-pick options
   comments?: string[], // additional comments to be posted
+  enableErrorNotification?: boolean, // enable the error notification on original pull request
 }

src/service/args/cli/cli-args-parser.ts

@@ -28,12 +28,13 @@ export default class CLIArgsParser extends ArgsParser {
       .option("--no-inherit-reviewers", "if provided and reviewers option is empty then inherit them from original pull request")
       .option("--labels <labels>", "comma separated list of labels to be assigned to the backported pull request", getAsCommaSeparatedList)
       .option("--inherit-labels", "if true the backported pull request will inherit labels from the original one")
-      .option("--no-squash", "Backport all commits found in the pull request. The default behavior is to only backport the first commit that was merged in the base branch")
-      .option("--auto-no-squash", "If the pull request was merged or is open, backport all commits. If the pull request commits were squashed, backport the squashed commit.")
+      .option("--no-squash", "backport all commits found in the pull request. The default behavior is to only backport the first commit that was merged in the base branch")
+      .option("--auto-no-squash", "if the pull request was merged or is open, backport all commits. If the pull request commits were squashed, backport the squashed commit.")
       .option("--strategy <strategy>", "cherry-pick merge strategy, default to 'recursive'", undefined)
       .option("--strategy-option <strategy-option>", "cherry-pick merge strategy option, default to 'theirs'")
       .option("--cherry-pick-options <options>", "additional cherry-pick options")
       .option("--comments <comments>", "semicolon separated list of additional comments to be posted to the backported pull request", getAsSemicolonSeparatedList)
+      .option("--enable-err-notification", "if true, enable the error notification as comment on the original pull request")
       .option("-cf, --config-file <config-file>", "configuration file containing all valid options, the json must match Args interface");
   }
 
@@ -72,6 +73,7 @@ export default class CLIArgsParser extends ArgsParser {
         strategyOption: opts.strategyOption,
         cherryPickOptions: opts.cherryPickOptions,
         comments: opts.comments,
+        enableErrorNotification: opts.enableErrNotification,
       };
     }
 

src/service/args/gha/gha-args-parser.ts

@@ -1,7 +1,7 @@
 import ArgsParser from "@bp/service/args/args-parser";
 import { Args } from "@bp/service/args/args.types";
 import { getInput } from "@actions/core";
-import { getAsBooleanOrDefault, getAsCleanedCommaSeparatedList, getAsCommaSeparatedList, getAsSemicolonSeparatedList, getOrUndefined, readConfigFile } from "@bp/service/args/args-utils";
+import { getAsBooleanOrUndefined, getAsCleanedCommaSeparatedList, getAsCommaSeparatedList, getAsSemicolonSeparatedList, getOrUndefined, readConfigFile } from "@bp/service/args/args-utils";
 
 export default class GHAArgsParser extends ArgsParser {
 
@@ -13,7 +13,7 @@ export default class GHAArgsParser extends ArgsParser {
       args = readConfigFile(configFile);
     } else {
       args = {
-        dryRun: getAsBooleanOrDefault(getInput("dry-run")),
+        dryRun: getAsBooleanOrUndefined(getInput("dry-run")),
         auth: getOrUndefined(getInput("auth")),
         pullRequest: getInput("pull-request"),
         targetBranch: getOrUndefined(getInput("target-branch")),
@@ -28,15 +28,16 @@ export default class GHAArgsParser extends ArgsParser {
         bpBranchName: getOrUndefined(getInput("bp-branch-name")),
         reviewers: getAsCleanedCommaSeparatedList(getInput("reviewers")),
         assignees: getAsCleanedCommaSeparatedList(getInput("assignees")),
-        inheritReviewers: !getAsBooleanOrDefault(getInput("no-inherit-reviewers")),
+        inheritReviewers: !getAsBooleanOrUndefined(getInput("no-inherit-reviewers")),
         labels: getAsCommaSeparatedList(getInput("labels")),
-        inheritLabels: getAsBooleanOrDefault(getInput("inherit-labels")),
-        squash: !getAsBooleanOrDefault(getInput("no-squash")),
-        autoNoSquash: getAsBooleanOrDefault(getInput("auto-no-squash")),
+        inheritLabels: getAsBooleanOrUndefined(getInput("inherit-labels")),
+        squash: !getAsBooleanOrUndefined(getInput("no-squash")),
+        autoNoSquash: getAsBooleanOrUndefined(getInput("auto-no-squash")),
         strategy: getOrUndefined(getInput("strategy")),
         strategyOption: getOrUndefined(getInput("strategy-option")),
         cherryPickOptions: getOrUndefined(getInput("cherry-pick-options")),
         comments: getAsSemicolonSeparatedList(getInput("comments")),
+        enableErrorNotification: getAsBooleanOrUndefined(getInput("enable-err-notification")),
       };
     }
 

src/service/configs/configs.types.ts

@@ -2,11 +2,19 @@
 
 import { BackportPullRequest, GitPullRequest } from "@bp/service/git/git.types";
 
+export const MESSAGE_ERROR_PLACEHOLDER = "{{error}}";
+export const MESSAGE_TARGET_BRANCH_PLACEHOLDER = "{{target-branch}}";
+
 export interface LocalGit {
   user: string, // local git user
   email: string, // local git email
 } 
 
+export interface ErrorNotification {
+  enabled: boolean, // if the error notification is enabled
+  message: string, // notification message, placeholder {{error}} will be replaced with actual error
+}
+
 /**
  * Internal configuration object
  */
@@ -20,6 +28,7 @@ export interface Configs {
   cherryPickOptions?: string, // additional cherry-pick options
   originalPullRequest: GitPullRequest,
   backportPullRequests: BackportPullRequest[],
+  errorNotification: ErrorNotification,
  }
 
 export enum AuthTokenId {

src/service/configs/pullrequest/pr-configs-parser.ts

@@ -1,7 +1,7 @@
 import { getAsCleanedCommaSeparatedList, getAsCommaSeparatedList } from "@bp/service/args/args-utils";
 import { Args } from "@bp/service/args/args.types";
 import ConfigsParser from "@bp/service/configs/configs-parser";
-import { Configs } from "@bp/service/configs/configs.types";
+import { Configs, MESSAGE_TARGET_BRANCH_PLACEHOLDER } from "@bp/service/configs/configs.types";
 import GitClient from "@bp/service/git/git-client";
 import GitClientFactory from "@bp/service/git/git-client-factory";
 import { BackportPullRequest, GitPullRequest } from "@bp/service/git/git.types";
@@ -58,7 +58,11 @@ export default class PullRequestConfigsParser extends ConfigsParser {
       git: {
         user: args.gitUser ?? this.gitClient.getDefaultGitUser(),
         email: args.gitEmail ?? this.gitClient.getDefaultGitEmail(),
-      }
+      },
+      errorNotification: {
+        enabled: args.enableErrorNotification ?? false,
+        message: this.getDefaultErrorComment(),
+      },
     };
   }
   
@@ -66,6 +70,11 @@ export default class PullRequestConfigsParser extends ConfigsParser {
     return "bp";
   }
 
+  private getDefaultErrorComment(): string {
+    // TODO: fetch from arg or set default with placeholder {{error}}
+    return `The backport to \`${MESSAGE_TARGET_BRANCH_PLACEHOLDER}\` failed. Check the latest run for more details.`;
+  }
+
   /**
    * Parse the provided labels and return a list of target branches
    * obtained by applying the provided pattern as regular expression extractor

src/service/git/git-client.ts

@@ -44,4 +44,11 @@ import { BackportPullRequest, GitClientType, GitPullRequest } from "@bp/service/
    */
   createPullRequest(backport: BackportPullRequest): Promise<string>;
 
+  /**
+   * Create a new comment on the provided pull request
+   * @param prUrl pull request's URL
+   * @param comment comment body
+   */
+  createPullRequestComment(prUrl: string, comment: string): Promise<string | undefined>;
+
 }

src/service/git/git.types.ts

@@ -1,7 +1,7 @@
 export interface GitPullRequest {
   number?: number,
   author: string,
-  url?: string,
+  url: string,
   htmlUrl?: string,
   state?: GitRepoState,
   merged?: boolean,

src/service/git/github/github-client.ts

@@ -158,6 +158,29 @@ export default class GitHubClient implements GitClient {
     return data.html_url;
   }
 
+  async createPullRequestComment(prUrl: string, comment: string): Promise<string | undefined> {
+    let commentUrl: string | undefined = undefined;
+    try {
+      const { owner, project, id } = this.extractPullRequestData(prUrl);
+      const { data } = await this.octokit.issues.createComment({
+        owner: owner,
+        repo: project,
+        issue_number: id,
+        body: comment
+      });
+  
+      if (!data) {
+        throw new Error("Pull request comment creation failed");
+      }
+  
+      commentUrl = data.url;
+    } catch (error) {
+      this.logger.error(`Error creating comment on pull request ${prUrl}: ${error}`);
+    }
+
+    return commentUrl;
+  }
+
   // UTILS
 
   /**

src/service/git/gitlab/gitlab-client.ts

@@ -162,6 +162,29 @@ export default class GitLabClient implements GitClient {
     return mr.web_url;
   }
 
+  // https://docs.gitlab.com/ee/api/notes.html#create-new-issue-note
+  async createPullRequestComment(mrUrl: string, comment: string): Promise<string | undefined> {
+    const commentUrl: string | undefined = undefined;
+    try{
+      const { namespace, project, id } = this.extractMergeRequestData(mrUrl);
+      const projectId = this.getProjectId(namespace, project);
+
+      const { data } = await this.client.post(`/projects/${projectId}/issues/${id}/notes`, {
+        body: comment,
+      });
+
+      if (!data) {
+        throw new Error("Merge request comment creation failed");
+      }
+    } catch(error) {
+      this.logger.error(`Error creating comment on merge request ${mrUrl}: ${error}`);
+    }
+    
+    return commentUrl;
+  }
+
+  // UTILS
+
   /**
    * Retrieve a gitlab user given its username
    * @param username 

src/service/logger/console-logger-service.ts

@@ -16,6 +16,10 @@ export default class ConsoleLoggerService implements LoggerService {
     this.context = newContext;
   }
 
+  getContext(): string | undefined {
+    return this.context;
+  }
+
   clearContext() {
     this.context = undefined;
   }

src/service/logger/logger-service.ts

@@ -5,6 +5,8 @@ export default interface LoggerService {
 
   setContext(newContext: string): void;
 
+  getContext(): string | undefined;
+
   clearContext(): void;
 
   trace(message: string): void;

src/service/runner/runner-util.ts

@@ -0,0 +1,22 @@
+import { MESSAGE_ERROR_PLACEHOLDER, MESSAGE_TARGET_BRANCH_PLACEHOLDER } from "@bp/service/configs/configs.types";
+
+/**
+ * Inject the error message in the provided `message`.
+ * This is injected in place of the MESSAGE_ERROR_PLACEHOLDER placeholder
+ * @param message string that needs to be updated
+ * @param errMsg the error message that needs to be injected
+ */
+export const injectError = (message: string, errMsg: string): string => {
+    return message.replace(MESSAGE_ERROR_PLACEHOLDER, errMsg);
+};
+
+/**
+ * Inject the target branch into the provided `message`.
+ * This is injected in place of the MESSAGE_TARGET_BRANCH_PLACEHOLDER placeholder
+ * @param message string that needs to be updated
+ * @param targetBranch the target branch to inject
+ * @returns 
+ */
+export const injectTargetBranch = (message: string, targetBranch: string): string => {
+    return message.replace(MESSAGE_TARGET_BRANCH_PLACEHOLDER, targetBranch);
+};

src/service/runner/runner.ts

@@ -9,6 +9,7 @@ import { BackportPullRequest, GitClientType, GitPullRequest } from "@bp/service/
 import LoggerService from "@bp/service/logger/logger-service";
 import LoggerServiceFactory from "@bp/service/logger/logger-service-factory";
 import { inferGitClient, inferGitApiUrl, getGitTokenFromEnv } from "@bp/service/git/git-util";
+import { injectError, injectTargetBranch } from "./runner-util";
 
 interface Git {
   gitClientType: GitClientType;
@@ -92,6 +93,12 @@ export default class Runner {
         });
       } catch(error) {
         this.logger.error(`Something went wrong backporting to ${pr.base}: ${error}`);
+        if (!configs.dryRun && configs.errorNotification.enabled && configs.errorNotification.message.length > 0) {
+          // notify the failure as comment in the original pull request
+          let comment = injectError(configs.errorNotification.message, error as string);
+          comment = injectTargetBranch(comment, pr.base);
+          await gitApi.createPullRequestComment(configs.originalPullRequest.url, comment);
+        }
         failures.push(error as string);
       }
     }
@@ -133,13 +140,12 @@ export default class Runner {
 
     // 5. create new branch from target one and checkout
     this.logger.debug("Creating local branch..");
-
     await git.gitCli.createLocalBranch(configs.folder, backportPR.head);
 
     // 6. fetch pull request remote if source owner != target owner or pull request still open
     if (configs.originalPullRequest.sourceRepo.owner !== configs.originalPullRequest.targetRepo.owner || 
         configs.originalPullRequest.state === "open") {
-          this.logger.debug("Fetching pull request remote..");
+      this.logger.debug("Fetching pull request remote..");
       const prefix = git.gitClientType === GitClientType.GITLAB ? "merge-requests" : "pull" ; // default is for gitlab
       await git.gitCli.fetch(configs.folder, `${prefix}/${configs.originalPullRequest.number}/head:pr/${configs.originalPullRequest.number}`);
     }
@@ -165,4 +171,4 @@ export default class Runner {
 
     this.logger.clearContext();
   }
-}
+}