Add tests for region loading

src/get-region.js

@@ -1,4 +1,4 @@
-let { existsSync, readFileSync } = require('fs/promises')
+let { existsSync, readFileSync } = require('fs')
 let { join } = require('path')
 let os = require('os')
 let ini = require('ini')
@@ -19,7 +19,7 @@ module.exports = function getRegion (params) {
     if (configRegion) return configRegion
   }
 
-  throw ReferenceError('Must supply AWS region via params, environment variables, or config file')
+  throw ReferenceError('You must supply AWS region via params, environment variables, or config file')
 }
 
 function getRegionFromEnv () {

test/unit/src/get-region-test.js

@@ -0,0 +1,129 @@
+let { readFileSync } = require('fs')
+let os = require('os')
+let { join } = require('path')
+let test = require('tape')
+let mockFs = require('mock-fs')
+let { resetAWSEnvVars } = require('../../lib')
+let cwd = process.cwd()
+let sut = join(cwd, 'src', 'get-region.js')
+let getRegion = require(sut)
+
+let mock = join(cwd, 'test', 'mock')
+let east1 = 'us-east-1'
+let west1 = 'us-west-1'
+let west2 = 'us-west-2'
+let num = 1
+let configMock = join(mock, '.aws', 'config')
+
+test('Set up env', t => {
+  t.plan(1)
+  t.ok(getRegion, 'getRegion module is present')
+})
+
+test('Get region from passed params', t => {
+  t.plan(1)
+  let region = east1
+  let result = getRegion({ region })
+  t.equal(result, region, 'Returned correct region from passed params')
+})
+
+test('Get region from env vars', t => {
+  t.plan(3)
+  resetAWSEnvVars()
+  let result
+
+  process.env.AWS_REGION = east1
+  result = getRegion({})
+  t.equal(result, east1, 'Returned correct region from env vars')
+  resetAWSEnvVars()
+
+  process.env.AWS_DEFAULT_REGION = east1
+  result = getRegion({})
+  t.equal(result, east1, 'Returned correct region from env vars')
+  resetAWSEnvVars()
+
+  process.env.AMAZON_REGION = east1
+  result = getRegion({})
+  t.equal(result, east1, 'Returned correct region from env vars')
+  resetAWSEnvVars()
+})
+
+test('Get region from config file', t => {
+  t.plan(5)
+  resetAWSEnvVars()
+  let result
+  let profile = 'profile_1'
+
+  // Default config file location
+  let home = os.homedir()
+  let configFile = join(home, '.aws', 'config')
+  mockFs({ [configFile]: readFileSync(configMock) })
+  process.env.AWS_SDK_LOAD_CONFIG = true
+  result = getRegion({})
+  t.equal(result, west1, 'Returned correct region from config file (~/.aws file location)')
+  mockFs.restore()
+  resetAWSEnvVars()
+
+  // Configured file locations
+  process.env.AWS_SDK_LOAD_CONFIG = true
+  process.env.AWS_CONFIG_FILE = configMock
+  result = getRegion({})
+  t.equal(result, west1, 'Returned correct region from config file (default profile)')
+  resetAWSEnvVars()
+
+  // params.profile
+  process.env.AWS_SDK_LOAD_CONFIG = true
+  process.env.AWS_CONFIG_FILE = configMock
+  result = getRegion({ profile: 'profile_1' })
+  t.equal(result, west2, 'Returned correct region from config file (params.profile)')
+  resetAWSEnvVars()
+
+  // AWS_PROFILE env var
+  process.env.AWS_SDK_LOAD_CONFIG = true
+  process.env.AWS_CONFIG_FILE = configMock
+  process.env.AWS_PROFILE = profile
+  result = getRegion({})
+  t.equal(result, west2, 'Returned correct region from config file (AWS_PROFILE env var)')
+  resetAWSEnvVars()
+
+  // Config file checks are skipped in Lambda
+  process.env.AWS_SDK_LOAD_CONFIG = true
+  process.env.AWS_CONFIG_FILE = configMock
+  process.env.AWS_LAMBDA_FUNCTION_NAME = 'true'
+  t.throws(() => {
+    getRegion({})
+  }, /You must supply AWS region/, 'Did not look for config file on disk in Lambda')
+  resetAWSEnvVars()
+})
+
+test('Validate config', t => {
+  t.plan(5)
+  resetAWSEnvVars()
+
+  t.throws(() => {
+    getRegion({ region: num })
+  }, /Region must be a string/, 'Threw on invalid region')
+
+  t.throws(() => {
+    getRegion({ region: 'us-south-14' })
+  }, /Invalid region specified/, 'Threw on invalid region')
+
+  t.throws(() => {
+    process.env.AWS_SDK_LOAD_CONFIG = true
+    process.env.AWS_CONFIG_FILE = configMock
+    process.env.AWS_PROFILE = 'idk'
+    getRegion({})
+  }, /Profile not found/, 'Threw on missing profile')
+  resetAWSEnvVars()
+
+  t.throws(() => {
+    process.env.AWS_SDK_LOAD_CONFIG = true
+    process.env.AWS_CONFIG_FILE = 'meh'
+    getRegion({})
+  }, /You must supply AWS region/, 'Threw on no available config (after attempting to checking filesystem)')
+  resetAWSEnvVars()
+
+  t.throws(() => {
+    getRegion({})
+  }, /You must supply AWS region/, 'Threw on no available config')
+})