Use TypeScript and compile to JS on release (#17)

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-coverage
+coverage
+dist

.npmignore

@@ -0,0 +1 @@
+!dist

circle.yml

@@ -11,6 +11,7 @@ test:
     - yarn lint
   override:
     - yarn test:cover
+    - yarn build
   post:
     - yarn coveralls
 

package.json

@@ -2,13 +2,13 @@
   "name": "serverless-dynamodb-autoscaling",
   "description": "Serverless Plugin for Amazon DynamoDB Auto Scaling.",
   "version": "0.0.0",
-  "main": "src/plugin.js",
+  "main": "dist/plugin.js",
   "scripts": {
-    "fix": "standard --fix",
-    "test": "jest test",
-    "test:cover": "jest test --coverage",
+    "test": "jest",
+    "test:cover": "jest --coverage",
     "coveralls": "cat ./coverage/lcov.info | coveralls",
-    "lint": "standard | snazzy"
+    "lint": "tslint {src,test}/**/*.ts",
+    "build": "tsc"
   },
   "keywords": [
     "serverless",
@@ -32,24 +32,29 @@
   },
   "homepage": "https://github.com/sbstjn/serverless-dynamodb-autoscaling",
   "devDependencies": {
+    "@types/jest": "^20.0.5",
+    "@types/node": "^8.0.19",
     "coveralls": "^2.13.1",
     "dot-json": "^1.0.3",
     "jest": "^20.0.4",
-    "snazzy": "^7.0.0",
-    "standard": "^10.0.2"
+    "ts-jest": "^20.0.7",
+    "tslint": "^5.5.0",
+    "@types/md5": "^2.1.32",
+    "@types/lodash": "^4.14.71",
+    "typescript": "^2.4.2"
   },
   "dependencies": {
     "lodash": "^4.17.4",
     "md5": "^2.2.1"
   },
-  "standard": {
-    "envs": [
-      "node",
-      "jest"
-    ],
-    "ignore": [
-      "node_modules/",
-      "coverage"
+  "jest": {
+    "transform": {
+      ".*": "<rootDir>/node_modules/ts-jest/preprocessor.js"
+    },
+    "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts)$",
+    "moduleFileExtensions": [
+      "ts",
+      "js"
     ]
   }
 }

src/aws/names.js → src/aws/names.ts

@@ -1,19 +1,19 @@
-const util = require('util')
-const md5 = require('md5')
+import * as md5 from 'md5'
+import * as util from 'util'
 
-function clean (input) {
+export function clean(input: string): string {
   return truncate(input.replace(/[^a-z0-9+]+/gi, ''))
 }
 
-function truncate (input) {
+export function truncate(input: string): string {
   return input.length <= 64 ? input : input.substr(0, 32) + md5(input)
 }
 
-function policyScale (service, table, read, index, stage) {
+export function policyScale(service: string, table: string, read: boolean, index?: string, stage?: string): string {
   return clean(
     util.format(
       '%sTable%sScalingPolicy-%s%s%s',
-      service || '',
+      service,
       read ? 'Read' : 'Write',
       table,
       index || '',
@@ -22,31 +22,31 @@ function policyScale (service, table, read, index, stage) {
   )
 }
 
-function policyRole (service, table, index, stage) {
+export function policyRole(service: string, table: string, index?: string, stage?: string): string {
   return clean(
     util.format(
       '%sDynamoDBAutoscalePolicy-%s%s%s',
-      service || '',
+      service,
       table,
       index || '',
       stage || ''
     )
   )
 }
 
-function dimension (read, index) {
+export function dimension(read: boolean, index: boolean): string {
   return util.format(
     'dynamodb:%s:%sCapacityUnits',
     index ? 'index' : 'table',
     read ? 'Read' : 'Write'
   )
 }
 
-function target (service, table, read, index, stage) {
+export function target(service: string, table: string, read: boolean, index?: string, stage?: string): string {
   return clean(
     util.format(
       '%sAutoScalingTarget%s-%s%s%s',
-      service || '',
+      service,
       read ? 'Read' : 'Write',
       table,
       index || '',
@@ -55,7 +55,7 @@ function target (service, table, read, index, stage) {
   )
 }
 
-function metric (read) {
+export function metric(read: boolean): string {
   return clean(
     util.format(
       'DynamoDB%sCapacityUtilization',
@@ -64,24 +64,14 @@ function metric (read) {
   )
 }
 
-function role (service, table, index, stage) {
+export function role(service: string, table: string, index?: string, stage?: string): string {
   return clean(
     util.format(
       '%sDynamoDBAutoscaleRole-%s%s%s',
-      service || '',
+      service,
       table,
       index || '',
       stage || ''
     )
   )
 }
-
-module.exports = {
-  clean,
-  dimension,
-  metric,
-  policyRole,
-  policyScale,
-  role,
-  target
-}

src/aws/policy.ts

@@ -0,0 +1,51 @@
+import * as names from './names'
+
+export default class Policy {
+  private dependencies: string[] = []
+  private type: string = 'AWS::ApplicationAutoScaling::ScalingPolicy'
+
+  constructor (
+    private service: string,
+    private table: string,
+    private value: number,
+    private read: boolean,
+    private scaleIn: number,
+    private scaleOut: number,
+    private index: string,
+    private stage: string
+  ) { }
+
+  public setDependencies(list: string[]): Policy {
+    this.dependencies = list
+
+    return this
+  }
+
+  public toJSON(): any {
+    const nameMetric = names.metric(this.read)
+    const nameScalePolicy = names.policyScale(this.service, this.table, this.read, this.index, this.stage)
+    const nameTarget = names.target(this.service, this.table, this.read, this.index, this.stage)
+
+    const dependencies = [this.table, nameTarget ].concat(this.dependencies)
+
+    return {
+      [nameScalePolicy]: {
+        DependsOn: dependencies,
+        Properties: {
+          PolicyName: nameScalePolicy,
+          PolicyType: 'TargetTrackingScaling',
+          ScalingTargetId: { Ref: nameTarget },
+          TargetTrackingScalingPolicyConfiguration: {
+            PredefinedMetricSpecification: {
+              PredefinedMetricType: nameMetric
+            },
+            ScaleInCooldown: this.scaleIn,
+            ScaleOutCooldown: this.scaleOut,
+            TargetValue: this.value
+          }
+        },
+        Type: this.type
+      }
+    }
+  }
+}