npm-build.sh

#!/bin/bash

# WHY?
# Because lambda function project directories tend to have unnecessary files (like tests, docs, etc.)
# This skips the cruft and zip up only these files:
# ./node_modules (This is recursive.)
# ./*.js   (This is not recursive. All *.js   files in the base directory are included, subdirectories are excluded.)
# ./*.json (This is not recursive. All *.json files in the base directory are included, subdirectories are excluded.)

# Note:
# Put your tests in ./tests/tests.js rather than ./tests.js to keep them from getting build into the zip

find -E . -iregex '^\./[^/]*\.js(on)?' -or -path './node_modules/*' | zip -@ lambda.zip

package.json

{
  "name": "example-package",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "find -E . -iregex '^\\./[^/]*\\.js(on)?' -or -path './node_modules/*' | zip -@ lambda.zip",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "aws-sdk": "^2.382.0"
  },
  "devDependencies": {
    "mocha": "^5.2.0",
    "standard": "^12.0.1"
  }
}