Add more whys (#48)

* Tidy up

* More whys

samples/config.sample.js

@@ -0,0 +1,23 @@
+// required environment variables
+[
+  'NODE_ENV',
+  'PORT'
+].forEach((name) => {
+  if (!process.env[name]) {
+    throw new Error(`Environment variable ${name} is missing`)
+  }
+})
+
+const config = {  
+  env: process.env.NODE_ENV,
+  logger: {
+    level: process.env.LOG_LEVEL || 'info',
+    enabled: process.env.BOOLEAN ? process.env.BOOLEAN.toLowerCase() === 'true' : false
+  },
+  server: {
+    port: Number(process.env.PORT)
+  }
+  // ...
+}
+
+module.exports = config;

samples/configWithTest.sample.js

@@ -0,0 +1,40 @@
+const joi = require('joi')
+
+const envVarsSchema = joi.object({  
+  NODE_ENV: joi.string()
+    .allow(['development', 'production', 'test', 'provision'])
+    .required(),
+  PORT: joi.number()
+    .required(),
+  LOGGER_LEVEL: joi.string()
+    .allow(['error', 'warn', 'info', 'verbose', 'debug', 'silly'])
+    .default('info'),
+  LOGGER_ENABLED: joi.boolean()
+    .truthy('TRUE')
+    .truthy('true')
+    .falsy('FALSE')
+    .falsy('false')
+    .default(true)
+}).unknown()
+  .required()
+
+const { error, value: envVars } = joi.validate(process.env, envVarsSchema)  
+if (error) {  
+  throw new Error(`Config validation error: ${error.message}`)
+}
+
+const config = {  
+  env: envVars.NODE_ENV,
+  isTest: envVars.NODE_ENV === 'test',
+  isDevelopment: envVars.NODE_ENV === 'development',
+  logger: {
+    level: envVars.LOGGER_LEVEL,
+    enabled: envVars.LOGGER_ENABLED
+  },
+  server: {
+    port: envVars.PORT
+  }
+  // ...
+}
+
+module.exports = config;