feat: Allow skipping comment when planfile is empty (#31)

action.yml

@@ -23,6 +23,10 @@ inputs:
     description: The header to use for the pull request comment.
     required: true
     default: 📝 Terraform Plan
+  skip-empty:
+    description: Whether to skip posting a pull request comment when no changes need to be performed.
+    required: true
+    default: "false"
 runs:
   using: node20
   main: dist/index.js

src/comment.ts

@@ -1,7 +1,7 @@
 import type { GitHub } from '@actions/github/lib/utils'
 import * as github from '@actions/github'
 import type { PullRequestEvent } from '@octokit/webhooks-types'
-import type { RenderedPlan } from './render'
+import { planIsEmpty, type RenderedPlan } from './render'
 
 function renderResources(resources: Record<string, string>): string {
   let result = ''
@@ -13,12 +13,7 @@ function renderResources(resources: Record<string, string>): string {
 }
 
 function renderBody(plan: RenderedPlan): string {
-  if (
-    !plan.createdResources &&
-    !plan.recreatedResources &&
-    !plan.updatedResources &&
-    !plan.deletedResources
-  ) {
+  if (planIsEmpty(plan)) {
     return '**→ No Resource Changes!**'
   }
 

src/index.ts

@@ -1,7 +1,7 @@
 import * as core from '@actions/core'
 import * as github from '@actions/github'
 import { createOrUpdateComment, renderComment } from './comment'
-import { renderPlan } from './render'
+import { planIsEmpty, renderPlan } from './render'
 
 async function run() {
   // 1) Setup
@@ -10,7 +10,8 @@ async function run() {
     planfile: core.getInput('planfile', { required: true }),
     terraformCmd: core.getInput('terraform-cmd', { required: true }),
     workingDirectory: core.getInput('working-directory', { required: true }),
-    header: core.getInput('header', { required: true })
+    header: core.getInput('header', { required: true }),
+    skipEmpty: core.getBooleanInput('skip-empty', { required: true })
   }
   const octokit = github.getOctokit(inputs.token)
 
@@ -24,10 +25,12 @@ async function run() {
   )
 
   // 3) Post comment
-  await core.group('Render comment', () => {
-    const comment = renderComment({ plan, header: inputs.header })
-    return createOrUpdateComment({ octokit, content: comment })
-  })
+  if (!inputs.skipEmpty || !planIsEmpty(plan)) {
+    await core.group('Render comment', () => {
+      const comment = renderComment({ plan, header: inputs.header })
+      return createOrUpdateComment({ octokit, content: comment })
+    })
+  }
 }
 
 async function main() {

src/render.ts

@@ -9,6 +9,15 @@ export type RenderedPlan = {
   deletedResources?: Record<string, string>
 }
 
+export function planIsEmpty(plan: RenderedPlan): boolean {
+  return (
+    !plan.createdResources &&
+    !plan.recreatedResources &&
+    !plan.updatedResources &&
+    !plan.deletedResources
+  )
+}
+
 type ResourceContent = {
   reason?: string
   lines: string[]