LIFF Inspector 🔬
The universal DevTools for LIFF (WebView) browser
LIFF Inspector is the official DevTools for LIFF(LNE Frontend Framework) that is integrated with the latest ChromeDevTools and built on top of the ChromeDevTools Protocol.
| LIFF browser | ChromeDevTools |
| --------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- |
|  |  |
---
[日本語版](./README_ja.md)
## TOC
- [Features](#features)
- [Getting Started](#getting-started)
- [Example](#example)
- [Roadmap](#roadmap)
- [Contribution](#contribution)
## Features
📱 Enable debugging LIFF Browser and WebView with debugging options disabled
🌍 Remote debug
🔬 Support `Elements`, `Console` and `NetWork` tabs of ChromeDevTools
## Getting Started
LIFF Inspector consists of two components:
- LIFF Inspector Server
- LIFF Inspector Plugin
LIFF Inspector Server is a server program that mediates communication between LIFF app and ChromeDevTools.
LIFF Inspector Plugin is a [LIFF Plugin](https://developers.line.biz/en/docs/liff/liff-plugin/). LIFF Plugin is available in LIFF SDK v2.19.0 or later.
### 1. Start LIFF Inspector Server
```sh
$ npx @line/liff-inspector
Debugger listening on ws://{IP Address}:9222
```
### 2. Install LIFF Inspector Plugin to your LIFF App
```sh
$ npm install @line/liff-inspector
```
```ts
import liff from '@line/liff';
import LIFFInspectorPlugin from '@line/liff-inspector';
liff.use(new LIFFInspectorPlugin());
```
### 3. Connect LIFF App and LIFF Inspector Server
Before the actual `liff.init` process, LIFF Inspector Plugin will try to connect LIFF Inspector Server.
Debugging with LIFF Inspector is available immediately after `liff.init` call.
```ts
liff.init({ liffId: 'liff-xxxx' }).then(() => {
// LIFF Inspector has been enabled
});
```
### 4. Open ChromeDevTools
After `liff.init`, LIFF Inspector Server shows the devtools URL for your LIFF App in console.
```diff
$ npx @line/liff-inspector
Debugger listening on ws://{IP Address}:9222
+ connection from client, id: xxx
+ DevTools URL: devtools://devtools/bundled/inspector.html?wss=8a6f-113-35-87-12.ngrok.io/?hi_id=xxx
```
Open the URL starts with `devtools://devtools/` and enjoy debugging!
## Important: LIFF Inspector Server need to be served over SSL/TLS
By default, LIFF Inspector Server starts a local server on `ws://localhost:9222`, and your LIFF App is served over HTTPS (`https://liff.line.me/xxx-yyy`). LIFF Inspector Plugin will try to connect to `ws://localhost:9222` from `https://liff.line.me/xxx-yyy` but this will fail due to [mixed content](https://developer.mozilla.org/en-US/docs/Web/Security/Mixed_content).
To eliminate mixed content, you need to serve LIFF Inspector Server over HTTPS (`wss://`). We have two recommended ways:
### Serve local server over HTTPS via 1 or 2
1. Using [ngrok](https://ngrok.com/) to make LIFF Inspector Server public
1. Run ngrok
```sh
$ ngrok http 9222
```
2. Copy the published URL
```sh
$ node -e "const res=$(curl -s -sS http://127.0.0.1:4040/api/tunnels); const url=new URL(res.tunnels[0].public_url); console.log('wss://'+url.host);"
wss://xxxx-xxx-xxx.ngrok # Copy this url
```
Or
2. Running LIFF Inspector Server with HTTPS using mkcert
- See the detail explanation: [How to use HTTPS for local development - web.dev](https://web.dev/how-to-use-local-https/)
### Set HTTPS URL to LIFF Inspector Plugin via 1 or 2
Once LIFF Inspector Server runs over HTTPS, you need to specify its origin to LIFF Inspector Plugin.
1. Use URL Search Parameter: `?li.origin=`
Add `?li.origin=` query to the Endpoint URL of your LIFF App in [LINE Developers Console](https://developers.line.biz/console).
Or
2. Use `origin` config of LIFF Inspector Plugin
```ts
// Default origin: ws://localhost:9222
liff.use(new LIFFInspectorPlugin({ origin: 'wss://xxx-xx-xx-xx.ngrok.io' }));
```
### Priority
LIFF Inspector Plugin attempts to connect to given origin in the order `li.origin` (1), `origin` config (2).
(Pseudo code)
```ts
const originFromURL = new URLSearchParams(search).get('li.origin');
const originFromConfig = config.origin;
const defaultOrigin = 'ws://localhost:9222';
connect(originFromURL ?? originFromConfig ?? defaultOrigin);
```
## Example
See https://github.com/cola119/liff-inspector-example
## Roadmap
**Contributions Welcome!**
### Elements Tab
- [x] To display Elements
- [x] To display overlays
- [ ] To remove/add/edit Elements
- [ ] To display styles
### Console Tab
- To display console logs
- [x] `console.log`
- [x] `console.warn`
- [x] `console.error`
- [x] `console.info`
- [ ] others
- [ ] To execute local scripts
### Network Tab
- To display simple network logs
- Fetch/XHR
- [x] `fetch()`
- [x] `XMLHttpRequest`
- [ ] `sendBeacon()`
- [ ] others
- Others(JS/CSS/Img/Media/Font...)
- Technically difficult to intercept them...
### Application Tab
- [ ] LocalStorage
- [ ] SessionStorage
- [ ] Cookies
- [ ] others
## Contribution
See [CONTRIBUTING.md](../../CONTRIBUTING.md)