Dynamic required messages

__tests__/main.test.ts

@@ -22,6 +22,19 @@ const main = await import('../src/main.js')
 const { Octokit } = await import('@octokit/rest')
 const mocktokit = jest.mocked(new Octokit())
 
+// Mirrors @actions/core's getInput: returns '' for unset inputs, throws when
+// a required input is empty (checked against the raw value, so whitespace-only
+// passes the check just like in production), trims the returned value by
+// default, and honors `trimWhitespace: false` to return the raw value.
+function mockInputs(values: Record<string, string>): void {
+  core.getInput.mockImplementation((name, options) => {
+    const value = values[name] ?? ''
+    if (options?.required && !value)
+      throw new Error(`Input required and not supplied: ${name}`)
+    return options?.trimWhitespace === false ? value : value.trim()
+  })
+}
+
 describe('main.ts', () => {
   afterEach(() => {
     jest.resetAllMocks()
@@ -40,10 +53,11 @@ describe('main.ts', () => {
     }
 
     // Set the action's inputs as return values from core.getInput().
-    core.getInput
-      .mockReturnValueOnce('ISSUE_MESSAGE')
-      .mockReturnValueOnce('PR_MESSAGE')
-      .mockReturnValueOnce('REPO_TOKEN')
+    mockInputs({
+      issue_message: 'ISSUE_MESSAGE',
+      pr_message: 'PR_MESSAGE',
+      repo_token: 'REPO_TOKEN'
+    })
   })
 
   describe('run()', () => {
@@ -156,6 +170,82 @@ describe('main.ts', () => {
 
       expect(mocktokit.rest.issues.createComment).toHaveBeenCalled()
     })
+
+    it('Does not require pr_message on an issue event', async () => {
+      github.context.payload.issue = {
+        number: 10
+      }
+      github.context.payload.pull_request = undefined as any
+
+      mockInputs({
+        issue_message: 'ISSUE_MESSAGE',
+        repo_token: 'REPO_TOKEN'
+      })
+
+      mocktokit.paginate
+        // Issues
+        .mockResolvedValueOnce([{ number: 10 }])
+        // PRs
+        .mockResolvedValueOnce([])
+
+      await expect(main.run()).resolves.toBeUndefined()
+      expect(mocktokit.rest.issues.createComment).toHaveBeenCalled()
+    })
+
+    it('Does not require issue_message on a PR event', async () => {
+      github.context.payload.issue = undefined as any
+      github.context.payload.pull_request = {
+        number: 10
+      }
+
+      mockInputs({
+        pr_message: 'PR_MESSAGE',
+        repo_token: 'REPO_TOKEN'
+      })
+
+      mocktokit.paginate
+        // Issues
+        .mockResolvedValueOnce([])
+        // PRs
+        .mockResolvedValueOnce([{ number: 10 }])
+
+      await expect(main.run()).resolves.toBeUndefined()
+      expect(mocktokit.rest.issues.createComment).toHaveBeenCalled()
+    })
+
+    it('Fails if issue_message is missing on an issue event', async () => {
+      github.context.payload.issue = {
+        number: 10
+      }
+      github.context.payload.pull_request = undefined as any
+
+      mockInputs({
+        pr_message: 'PR_MESSAGE',
+        repo_token: 'REPO_TOKEN'
+      })
+
+      await expect(main.run()).rejects.toThrow(
+        'Input required and not supplied: issue_message'
+      )
+      expect(mocktokit.rest.issues.createComment).not.toHaveBeenCalled()
+    })
+
+    it('Fails if pr_message is missing on a PR event', async () => {
+      github.context.payload.issue = undefined as any
+      github.context.payload.pull_request = {
+        number: 10
+      }
+
+      mockInputs({
+        issue_message: 'ISSUE_MESSAGE',
+        repo_token: 'REPO_TOKEN'
+      })
+
+      await expect(main.run()).rejects.toThrow(
+        'Input required and not supplied: pr_message'
+      )
+      expect(mocktokit.rest.issues.createComment).not.toHaveBeenCalled()
+    })
   })
 
   describe('isFirstIssue()', () => {

src/main.ts

@@ -28,10 +28,9 @@ export async function run() {
     )
 
   // Get the action inputs.
-  const issueMessage: string = core.getInput('issue_message', {
-    required: true
-  })
-  const prMessage: string = core.getInput('pr_message', { required: true })
+  const commentBody: string = isIssue
+    ? core.getInput('issue_message', { required: true })
+    : core.getInput('pr_message', { required: true })
 
   const octokit = new Octokit({
     auth: core.getInput('repo_token', { required: true })
@@ -47,7 +46,7 @@ export async function run() {
     owner: github.context.repo.owner,
     repo: github.context.repo.repo,
     issue_number: github.context.issue.number,
-    body: isIssue ? issueMessage : prMessage
+    body: commentBody
   })
 }