Rename to cjs for improved support

Author: archive

CLAUDE.md

@@ -6,7 +6,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 A GitHub Action that sends messages, reactions, threads, and block-based messages to Slack via the Slack API. Written in JavaScript with one runtime dependency: `@actions/core`.
 
-- **Action entry point:** `dist/index.js` (compiled bundle — never edit this directly)
+- **Action entry point:** `dist/index.cjs` (compiled bundle — never edit this directly)
 - **Source entry point:** `index.js` → `src/invoke.js`
 
 ## Commands
@@ -15,7 +15,7 @@ A GitHub Action that sends messages, reactions, threads, and block-based message
 npm test                   # Run Jest unit tests (src/ only)
 npm run test-debug         # Debug Jest with Node inspector
 npm run lint               # ESLint with auto-fix
-npm run build              # Compile dist/index.js via esbuild (required before deploy)
+npm run build              # Compile dist/index.cjs via esbuild (required before deploy)
 ```
 
 Integration test (requires real Slack token):
@@ -27,7 +27,7 @@ $env:BOT_USER_OAUTH_ACCESS_TOKEN="<token>"; $env:CHANNEL="<channel-id>"; node in
 BOT_USER_OAUTH_ACCESS_TOKEN=<token> CHANNEL=<channel-id> node integration-test/end-to-end.js
 ```
 
-**After any source change, run `npm run build` to update `dist/index.js`.** The action runs from `dist/index.js`, not the source files.
+**After any source change, run `npm run build` to update `dist/index.cjs`.** The action runs from `dist/index.cjs`, not the source files.
 
 ## Architecture
 

README.md

@@ -409,6 +409,10 @@ It was a good way to learn more about Github Actions
 
 This action is just an HTTPS POST to Slack API, so you can easily build this by yourself, or use this, or use any other action available on the marketplace :)
 
+## v2 → v3: CommonJS vs ES Modules
+
+The source code moved from CommonJS (`require`) to ES Modules (`import`/`export`) in v3, with `"type": "module"` in `package.json`. However, the bundled action entry point (`dist/index.cjs`) is still built as CommonJS using esbuild. This is intentional for now,`@actions/core` and its dependencies (e.g. `tunnel`) use dynamic `require()` calls for Node built-ins like `net` and `tls`, which fail at runtime inside an ESM bundle. Building the action as CJS avoids this.
+
 ## Development and testing
 
 See package.json for `yarn lint`, `yarn test`, etc.

action.yml

@@ -79,4 +79,4 @@ outputs:
     description: "The result from the post to slack"
 runs:
   using: "node24"
-  main: "dist/index.js"
+  main: "dist/index.cjs"