Ability to exclude paths in input-output-logger

packages/input-output-logger/README.md

@@ -45,6 +45,7 @@ npm install --save @middy/input-output-logger
 ## Options
 
 `logger` property accept a function (default `console.log`)
+`omitPaths` property accepts an array of paths that will be used to remove particular fields from the logged objects. This could serve as a simple way to redact sensitive data from logs (default []).
 
 
 ## Sample usage

packages/input-output-logger/__tests__/index.js

@@ -18,4 +18,36 @@ describe('📦 Middleware Input Output Logger', () => {
     expect(logger).toHaveBeenCalledWith({ event: { foo: 'bar', fuu: 'baz' } })
     expect(logger).toHaveBeenCalledWith({ response: { message: 'hello world' } })
   })
+  describe('omitPaths', () => {
+    test('It should omit paths', async () => {
+      const logger = jest.fn()
+
+      const handler = middy((event, context, cb) => {
+        cb(null, { message: 'hello world', bar: 'bi' })
+      })
+
+      handler
+        .use(inputOutputLogger({ logger, omitPaths: ['event.foo', 'response.bar'] }))
+
+      await invoke(handler, { foo: 'bar', fuu: 'baz' })
+
+      expect(logger).toHaveBeenCalledWith({ event: { fuu: 'baz' } })
+      expect(logger).toHaveBeenCalledWith({ response: { message: 'hello world' } })
+    })
+    test('It should skip paths that do not exist', async () => {
+      const logger = jest.fn()
+
+      const handler = middy((event, context, cb) => {
+        cb(null, 'yo')
+      })
+
+      handler
+        .use(inputOutputLogger({ logger, omitPaths: ['event.zooloo', 'event.foo.hoo', 'response.bar'] }))
+
+      await invoke(handler, { foo: 'bar', fuu: 'baz' })
+
+      expect(logger).toHaveBeenCalledWith({ event: { foo: 'bar', fuu: 'baz' } })
+      expect(logger).toHaveBeenCalledWith({ response: 'yo' })
+    })
+  })
 })

packages/input-output-logger/index.d.ts

@@ -2,6 +2,7 @@ import middy from '@middy/core';
 
 interface IInputOutputLoggerOptions {
   logger?: (message: any) => void;
+  omitPaths?: string[];
 }
 
 declare const inputOutputLogger : middy.Middleware<IInputOutputLoggerOptions, any, any>

packages/input-output-logger/index.js

@@ -1,21 +1,29 @@
+const omit = require('lodash/omit')
+
 module.exports = (opts) => {
   const defaults = {
-    logger: data => console.log(JSON.stringify(data, null, 2))
+    logger: data => console.log(JSON.stringify(data, null, 2)),
+    omitPaths: []
   }
 
-  const options = Object.assign({}, defaults, opts)
+  const { logger, omitPaths } = Object.assign({}, defaults, opts)
+
+  const omitAndLog = message => {
+    const redactedMessage = omit(message, omitPaths)
+    logger(redactedMessage)
+  }
 
   return ({
     before: (handler, next) => {
-      if (typeof options.logger === 'function') {
-        options.logger({ event: handler.event })
+      if (typeof logger === 'function') {
+        omitAndLog({ event: handler.event })
       }
 
       return next()
     },
     after: (handler, next) => {
-      if (typeof options.logger === 'function') {
-        options.logger({ response: handler.response })
+      if (typeof logger === 'function') {
+        omitAndLog({ response: handler.response })
       }
 
       return next()

packages/input-output-logger/package.json

@@ -44,10 +44,12 @@
     "aws-sdk": ">=2.221.1"
   },
   "dependencies": {
-    "@types/node": "^10.0.8"
+    "lodash": "^4.17.15"
   },
   "devDependencies": {
     "@middy/core": "^1.0.0-beta.10",
+    "@types/node": "^10.0.8",
+    "@types/lodash": "^4.14.149",
     "es6-promisify": "^6.0.2"
   },
   "gitHead": "7a6c0fbb8ab71d6a2171e678697de9f237568431"