fix(webhook): add health check

Signed-off-by: Innei <i@innei.in>

packages/webhook/src/handler.ts

@@ -20,35 +20,51 @@ export const createHandler = (options: CreateHandlerOptions): Handler => {
   const { secret } = options
 
   const handler: Handler = async function (req, res) {
-    const signature = req.headers['x-webhook-signature']
-    assert(typeof signature === 'string', 'X-Webhook-Signature must be string')
-    const event = req.headers['x-webhook-event']
-    const signature256 = req.headers['x-webhook-signature256']
-    assert(
-      typeof signature256 === 'string',
-      'X-Webhook-Signature256 must be string',
-    )
+    try {
+      const signature = req.headers['x-webhook-signature']
+      assert(
+        typeof signature === 'string',
+        'X-Webhook-Signature must be string',
+      )
+      const event = req.headers['x-webhook-event']
+      const signature256 = req.headers['x-webhook-signature256']
+      assert(
+        typeof signature256 === 'string',
+        'X-Webhook-Signature256 must be string',
+      )
 
-    const obj = (req as any).body || (await parseJSONFromRequest(req))
-    const stringifyPayload = JSON.stringify(obj)
-    const isValid =
-      verifyWebhook(secret, stringifyPayload, signature256 as string) &&
-      verifyWebhookSha1(secret, stringifyPayload, signature as string)
+      const obj = (req as any).body || (await parseJSONFromRequest(req))
+      const stringifyPayload = JSON.stringify(obj)
+      const isValid =
+        verifyWebhook(secret, stringifyPayload, signature256 as string) &&
+        verifyWebhookSha1(secret, stringifyPayload, signature as string)
+      if (isValid) {
+        if (event === 'health_check') {
+          res.statusCode = 200
+          res.setHeader('Content-Type', 'application/json')
+          res.end(JSON.stringify({ ok: 1 }))
+          return
+        }
 
-    if (isValid) {
-      handler.emitter.emit(event as BusinessEvents, obj)
-      handler.emitter.emit('*', {
-        type: event,
-        payload: obj,
-      })
-      res.statusCode = 200
-      res.end()
-    } else {
-      console.error('revice a invalidate webhook payload', req.headers)
-      handler.emitter.emit('error', new Error('invalidate signature'))
+        handler.emitter.emit(event as BusinessEvents, obj)
+        handler.emitter.emit('*', {
+          type: event,
+          payload: obj,
+        })
+        res.statusCode = 200
+        res.setHeader('Content-Type', 'application/json')
+        res.end(JSON.stringify({ ok: 1 }))
+      } else {
+        console.error('revice a invalidate webhook payload', req.headers)
+        handler.emitter.emit('error', new Error('invalidate signature'))
 
-      res.statusCode = 400
-      res.end('invalidate signature')
+        res.statusCode = 400
+        res.setHeader('Content-Type', 'application/json')
+        res.end(JSON.stringify({ ok: 0, message: 'Invalid Signature' }))
+      }
+    } catch (err) {
+      res.statusCode = 500
+      res.end(JSON.stringify({ ok: 0, message: err.message }))
     }
   }