feat: prevent re-runs of release workflow on merged pull requests

src/changelog.ts

@@ -10,7 +10,7 @@ import type { TerraformChangedModule, TerraformModule } from './terraform-module
  * @param {Array<string>} commits - An array of commit messages to include in the changelog.
  * @returns {string} A formatted changelog entry as a string.
  */
-const createModuleChangelogEntry = (heading: string, commits: string[]): string => {
+function createModuleChangelogEntry(heading: string, commits: string[]): string {
   const currentDate = new Date().toISOString().split('T')[0]; // Format: YYYY-MM-DD
   const changelogContent: string[] = [`## \`${heading}\` (${currentDate})\n`];
 
@@ -19,15 +19,15 @@ const createModuleChangelogEntry = (heading: string, commits: string[]): string
   }
 
   return changelogContent.join('\n');
-};
+}
 
 /**
  * Retrieves the global pull request changelog.
  *
  * @param {TerraformChangedModule[]} terraformChangedModules - An array of changed Terraform modules.
  * @returns {string} The content of the global pull request changelog.
  */
-export const getPullRequestChangelog = (terraformChangedModules: TerraformChangedModule[]): string => {
+export function getPullRequestChangelog(terraformChangedModules: TerraformChangedModule[]): string {
   const pullRequestChangelog: string[] = [];
   const { prNumber, prTitle } = context;
 
@@ -47,15 +47,15 @@ export const getPullRequestChangelog = (terraformChangedModules: TerraformChange
   }
 
   return pullRequestChangelog.join('\n\n');
-};
+}
 
 /**
  * Retrieves the changelog for a specific Terraform module.
  *
  * @param {ChangedTerraformModule} changedTerraformModule - The Terraform module whose changelog is to be retrieved.
  * @returns {string} The content of the module's changelog.
  */
-export const getModuleChangelog = (terraformChangedModule: TerraformChangedModule): string => {
+export function getModuleChangelog(terraformChangedModule: TerraformChangedModule): string {
   const { prNumber, prTitle, repoUrl } = context;
   const { nextTagVersion, commitMessages } = terraformChangedModule;
 
@@ -75,7 +75,7 @@ export const getModuleChangelog = (terraformChangedModule: TerraformChangedModul
   ];
 
   return createModuleChangelogEntry(nextTagVersion, commitMessagesWithPR);
-};
+}
 
 /**
  * Generates a changelog for a given Terraform module by concatenating the body

src/config.ts

@@ -68,7 +68,7 @@ const getKeywords = (inputName: string): string[] => {
 /**
  * Lazy-initialized configuration object.
  */
-const initializeConfig = (): Config => {
+function initializeConfig(): Config {
   if (configInstance) {
     return configInstance;
   }
@@ -100,6 +100,6 @@ const initializeConfig = (): Config => {
   endGroup();
 
   return configInstance;
-};
+}
 
 export const config: Config = initializeConfig();

src/constants.ts

@@ -1,2 +1,7 @@
 export const GITHUB_ACTIONS_BOT_NAME = 'GitHub Actions';
 export const GITHUB_ACTIONS_BOT_EMAIL = '41898282+github-actions[bot]@users.noreply.github.com';
+
+export const PR_SUMMARY_MARKER = '<!-- techpivot/terraform-module-releaser — pr-summary-marker -->';
+export const PR_RELEASE_MARKER = '<!-- techpivot/terraform-module-releaser — release-marker -->';
+
+export const ERROR_PERMISSIONS = 'Ensure that the GitHub Actions workflow has the correct permissions';

src/context.ts

@@ -89,7 +89,7 @@ let contextInstance: Context | null = null;
  * @returns {string} The value of the environment variable.
  * @throws {Error} If the environment variable is missing or invalid.
  */
-const getRequiredEnvironmentVar = (name: string): string => {
+function getRequiredEnvironmentVar(name: string): string {
   const value = process.env[name];
   if (!value || typeof value !== 'string') {
     const errorMessage = `The ${name} environment variable is missing or invalid. This variable should be automatically set by GitHub for each workflow run. If this variable is missing or not correctly set, it indicates a serious issue with the GitHub Actions environment, potentially affecting the execution of subsequent steps in the workflow. Please review the workflow setup or consult the documentation for proper configuration.`;
@@ -98,14 +98,14 @@ const getRequiredEnvironmentVar = (name: string): string => {
   }
 
   return value;
-};
+}
 
 /**
  * Additional type guard to check if an object is a valid PullRequestEvent. By definition, we know that
  * because the GITHUB_EVENT_NAME is "pull_request" the payload will be a PullRequestEvent. However,
  * this validates runtime data additionally.
  */
-const isPullRequestEvent = (payload: unknown): payload is PullRequestEvent => {
+function isPullRequestEvent(payload: unknown): payload is PullRequestEvent {
   return (
     typeof payload === 'object' &&
     payload !== null &&
@@ -119,7 +119,7 @@ const isPullRequestEvent = (payload: unknown): payload is PullRequestEvent => {
     typeof (payload as PullRequestEvent).repository === 'object' &&
     typeof (payload as PullRequestEvent).repository.full_name === 'string'
   );
-};
+}
 
 /**
  * Lazily initializes the context object that contains details about the pull request and repository.
@@ -131,7 +131,7 @@ const isPullRequestEvent = (payload: unknown): payload is PullRequestEvent => {
  * @returns {Context} The context object containing GitHub client and pull request information.
  * @throws {Error} If this workflow is not running in the context of a pull request.
  */
-const initializeContext = (): Context => {
+function initializeContext(): Context {
   if (contextInstance) {
     return contextInstance;
   }
@@ -195,7 +195,7 @@ const initializeContext = (): Context => {
   } finally {
     endGroup();
   }
-};
+}
 
 /**
  * The exported `context` object, lazily initialized on first access, provides information about the repository,

src/main.ts

@@ -1,7 +1,7 @@
 import { info, setFailed } from '@actions/core';
 import { config } from './config';
 import { context } from './context';
-import { commentOnPullRequest, getPullRequestCommits } from './pull-request';
+import { addPostReleaseComment, addReleasePlanComment, getPullRequestCommits, hasReleaseComment } from './pull-request';
 import { createTaggedRelease, deleteLegacyReleases, getAllReleases } from './releases';
 import { deleteLegacyTags, getAllTags } from './tags';
 import { installTerraformDocs } from './terraform-docs';
@@ -15,7 +15,10 @@ import { WikiStatus } from './wiki';
  */
 export async function run(): Promise<void> {
   try {
-    // @todo early exit check
+    if (await hasReleaseComment()) {
+      info('Release comment found. Exiting.');
+      return;
+    }
 
     // Fetch all commits along with associated files in this PR
     const commits = await getPullRequestCommits();
@@ -55,7 +58,7 @@ export async function run(): Promise<void> {
         failure = errorMessage;
         error = err as Error;
       } finally {
-        await commentOnPullRequest(terraformChangedModules, terraformModuleNamesToRemove, {
+        await addReleasePlanComment(terraformChangedModules, terraformModuleNamesToRemove, {
           status: wikiStatus,
           errorMessage: failure,
         });
@@ -66,8 +69,9 @@ export async function run(): Promise<void> {
         throw error;
       }
     } else {
-      // Create the tagged release
-      await createTaggedRelease(terraformChangedModules);
+      // Create the tagged release and post a comment to the PR
+      const updatedModules = await createTaggedRelease(terraformChangedModules);
+      await addPostReleaseComment(updatedModules);
 
       // Delete legacy releases and tags (Ensure we delete releases first)
       await deleteLegacyReleases(terraformModuleNamesToRemove, allReleases);