Handle all async errors

Author: razor-x

handlers/app.js

@@ -7,9 +7,13 @@ const region = 'us-east-1'
 
 const createHandler = stage => (event, context, callback) => {
   const handleRequest = (err, options) => {
-    if (err) return callback(err)
-    const req = formatReq(event)
-    getResponse(req, options, callback)
+    try {
+      if (err) return callback(err)
+      const req = formatReq(event)
+      getResponse(req, options, callback)
+    } catch (error) {
+      callback(error)
+    }
   }
   getOptions({ region, stage, name }, handleRequest)
 }

lib/config.js

@@ -28,19 +28,27 @@ const getOptionsFromParameters = params => {
 }
 
 const getParameters = ({ region, stage, name }, callback) => {
-  const ssm = new SSM({ region })
-  const Names = parameterNames.map(
-    k => ['/app', name, stage, k].join('/')
-  )
-  const params = { Names }
-  ssm.getParameters(params, callback)
+  try {
+    const ssm = new SSM({ region })
+    const Names = parameterNames.map(
+      k => ['/app', name, stage, k].join('/')
+    )
+    const params = { Names }
+    ssm.getParameters(params, callback)
+  } catch (error) {
+    callback(error)
+  }
 }
 
 const getOptions = ({ region, stage, name } = {}, callback) => {
   getParameters({ region, stage, name }, (err, data) => {
-    if (err) return callback(err)
-    const options = getOptionsFromParameters(data.Parameters)
-    callback(null, options)
+    try {
+      if (err) return callback(err)
+      const options = getOptionsFromParameters(data.Parameters)
+      callback(null, options)
+    } catch (error) {
+      callback(error)
+    }
   })
 }
 

lib/response.js

@@ -6,18 +6,25 @@ const createContent = require('./content')
 
 const getBody = (content, callback) => {
   gzip(content, (err, buffer) => {
-    if (err) return callback(err)
-    const body = buffer.toString('base64')
-    callback(null, body)
+    try {
+      if (err) return callback(err)
+      const body = buffer.toString('base64')
+      callback(null, body)
+    } catch (error) {
+      callback(error)
+    }
   })
 }
 
-const getIndexResponse = (options, callback) => {
-  const content = createContent(options)
+const getIndexResponse = (content, callback) => {
   getBody(content, (err, body) => {
-    if (err) return callback(err)
-    const response = createIndexResponse(body)
-    callback(null, response)
+    try {
+      if (err) return callback(err)
+      const response = createIndexResponse(body)
+      callback(null, response)
+    } catch (error) {
+      callback(error)
+    }
   })
 }
 
@@ -56,11 +63,19 @@ const createFaviconResponse = ({
 })
 
 const getResponse = (req, options, callback) => {
-  const opts = extendOptions(options)
-  if (req.url === '/favicon.ico') {
-    return callback(null, createFaviconResponse(opts))
+  try {
+    const opts = extendOptions(options)
+
+    if (req.url === '/favicon.ico') {
+      const favicon = createFaviconResponse(opts)
+      return callback(null, favicon)
+    }
+
+    const content = createContent(options)
+    getIndexResponse(content, callback)
+  } catch (error) {
+    callback(error)
   }
-  getIndexResponse(opts, callback)
 }
 
 const extendOptions = options => {

server.js

@@ -44,7 +44,7 @@ const server = createServer((req, res) => {
 
   getResponse(req, options, (err, response) => {
     try {
-      if (err) handleError(err)
+      if (err) return handleError(err)
       handleResponse(response)
     } catch (error) {
       handleError(error)