Add comment-body-no-diff option

.github/workflows/ts.yaml

@@ -50,6 +50,13 @@ jobs:
           label: changed
       - run: test ${{ steps.no-diff.outputs.different }} = false
 
+      - name: e2e-test (comment-body-no-diff)
+        uses: ./
+        with:
+          base: tests/fixtures/head
+          head: tests/fixtures/head
+          comment-body-no-diff: ''
+
   generate:
     runs-on: ubuntu-latest
     timeout-minutes: 10

README.md

@@ -13,7 +13,7 @@ To post a comment of the diff between `old-directory` and `new-directory`,
     head: new-directory
 ```
 
-If no difference, it post a comment of "No diff".
+If no difference, it post a comment of "No diff" by default.
 
 ### Show diff of generated manifests
 
@@ -67,6 +67,24 @@ To add label(s) if there is difference or remove it if not:
     label: manifest-changed
 ```
 
+### No diff comment
+
+To change the comment of when no difference,
+
+```yaml
+- uses: int128/diff-action@v1
+  with:
+    comment-body-no-diff: No diff of kustomize build
+```
+
+To suppress any comment when no difference,
+
+```yaml
+- uses: int128/diff-action@v1
+  with:
+    comment-body-no-diff: ''
+```
+
 ### Comment strategy
 
 This action supports the following strategies:
@@ -87,11 +105,12 @@ This action posts a comment on `pull_request` or `pull_request_target` event onl
 
 ### Inputs
 
-| Name                   | Required                                   | Description                                                |
+| Name                   | Default                                    | Description                                                |
 | ---------------------- | ------------------------------------------ | ---------------------------------------------------------- |
 | `base`                 | (required)                                 | Path(s) of base (multiline)                                |
 | `head`                 | (required)                                 | Path(s) of head (multiline)                                |
 | `label`                | -                                          | Label(s) to add or remove to indicate the diff (multiline) |
+| `comment-body-no-diff` | No diff                                    | Comment body when no difference                            |
 | `comment-header`       | -                                          | Header of a comment to post                                |
 | `comment-footer`       | -                                          | Footer of a comment to post                                |
 | `update-if-exists`     | (optional)                                 | Either `create`, `replace`, `append` or `recreate`         |

action.yaml

@@ -10,6 +10,10 @@ inputs:
   label:
     description: Label(s) to add or remove to indicate the diff (multiline)
     required: false
+  comment-body-no-diff:
+    description: Comment body when no difference
+    required: false
+    default: No diff
   comment-header:
     description: Header of a comment to post
     required: false

src/comment.ts

@@ -16,6 +16,10 @@ export const addComment = async (github: GitHubContext, comment: Comment): Promi
   }
 
   if (comment.updateIfExists === 'create') {
+    if (comment.body === '') {
+      core.info('Nothing to create')
+      return
+    }
     core.info(`Creating a comment to #${github.issueNumber}`)
     const { data: created } = await github.octokit.rest.issues.createComment({
       owner: github.owner,
@@ -32,6 +36,10 @@ export const addComment = async (github: GitHubContext, comment: Comment): Promi
   const existingComment = await findComment(github, commentKey)
   if (!existingComment) {
     core.info(`Key not found in #${github.issueNumber}`)
+    if (comment.body === '') {
+      core.info('Nothing to create')
+      return
+    }
     const { data: created } = await github.octokit.rest.issues.createComment({
       owner: github.owner,
       repo: github.repo,
@@ -50,7 +58,10 @@ export const addComment = async (github: GitHubContext, comment: Comment): Promi
       comment_id: existingComment.id,
     })
     core.info(`Deleted the comment ${existingComment.html_url}`)
-
+    if (comment.body === '') {
+      core.info('Nothing to create')
+      return
+    }
     const { data: created } = await github.octokit.rest.issues.createComment({
       owner: github.owner,
       repo: github.repo,

src/format.ts

@@ -2,13 +2,17 @@ import * as core from '@actions/core'
 import { Diff } from './diff.js'
 
 type CommentOptions = {
+  bodyNoDiff: string
   header: string
   footer: string
   workflowRunURL: string
 }
 
 export const formatComment = (diffs: Diff[], o: CommentOptions): string => {
   if (diffs.length === 0) {
+    if (o.bodyNoDiff === '') {
+      return ''
+    }
     return generateNoDiffComment(o)
   }
 
@@ -35,7 +39,7 @@ export const formatComment = (diffs: Diff[], o: CommentOptions): string => {
 const generateNoDiffComment = (o: CommentOptions): string => `\
 ${o.header}
 
-No diff
+${o.bodyNoDiff}
 
 ${o.footer}`
 

src/main.ts

@@ -8,6 +8,7 @@ const main = async (): Promise<void> => {
     base: core.getInput('base', { required: true }),
     head: core.getInput('head', { required: true }),
     label: core.getMultilineInput('label', { required: false }),
+    commentBodyNoDiff: core.getInput('comment-body-no-diff'),
     commentHeader: core.getInput('comment-header'),
     commentFooter: core.getInput('comment-footer'),
     updateIfExists: updateIfExistsValue(core.getInput('update-if-exists')),

src/run.ts

@@ -9,6 +9,7 @@ type Inputs = {
   base: string
   head: string
   label: string[]
+  commentBodyNoDiff: string
   commentHeader: string
   commentFooter: string
   updateIfExists: UpdateIfExistsType
@@ -26,6 +27,7 @@ export const run = async (github: GitHubContext, inputs: Inputs): Promise<Output
 
   const diffs = await computeDiff(inputs.base, inputs.head)
   const body = formatComment(diffs, {
+    bodyNoDiff: inputs.commentBodyNoDiff,
     header: inputs.commentHeader,
     footer: inputs.commentFooter,
     workflowRunURL: github.workflowRunURL,

tests/format.test.ts

@@ -25,6 +25,7 @@ test('formatComment', () => {
       },
     ],
     {
+      bodyNoDiff: 'No diff',
       header: '## diff',
       footer: '<!-- diff-action -->',
       workflowRunURL: 'https://github.com/int128/diff-action/actions/runs/6282216330',