feat: extend concept to add application pre and action

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "typescript.tsdk": "node_modules/typescript/lib"
+}

packages/sls-app/jest.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  setupFilesAfterEnv: ['jest-extended']
+}

packages/sls-app/package.json

@@ -1,9 +1,16 @@
 {
-  "name": "sls-app",
+  "name": "@cabiri-io/sls-app",
   "version": "1.0.0",
   "main": "index.js",
   "license": "MIT",
   "scripts": {
     "test": "jest"
+  },
+  "devDependencies": {
+    "@types/jest": "^26.0.0",
+    "jest": "^26.0.1",
+    "jest-extended": "^0.11.5",
+    "ts-jest": "^26.1.0",
+    "typescript": "^3.9.5"
   }
 }

packages/sls-app/src/index.ts

@@ -1,7 +1,9 @@
+type ActionFunction<P, D, R> = (payload: P, dependencies: D) => R
+
 // configuration I want to be able to debug invocation
 type Application<P, D, R> = {
   pre(actionContextFunction: ActionContextFunction<P, D>): Application<P, D, R>
-  action(): Application<P, D, R>
+  action(actionFunction: ActionFunction<P, D, R>): Application<P, D, R> | never
   post(): Application<P, D, R>
   run(payload: P, dependencies: D): Promise<R>
 }
@@ -18,35 +20,42 @@ type PreAction<P, D> = {
   // maybe we have type
 }
 
+export class ApplicationError extends Error {
+  public type: string = 'ApplicationError'
+}
+
 // allow to configure the application e.g. log each entry
-export function Application<P, D, R>(): Application<P, D, R> {
+export function application<P, D, R>(): Application<P, D, R> {
   // maybe instead of using array we an explore using Task concept and
   // and instead we can just compose function
 
   const preActions: Array<PreAction<P, D>> = []
+  let mainAction: ActionFunction<P, D, R>
   return {
     pre(actionFunction) {
       // allow to push logger
       preActions.push({ func: actionFunction })
       return this
     },
-    action() {
+
+    action(actionFunction) {
+      //@ts-ignore
+      if (mainAction) throw new ApplicationError('you can only have a single action')
+      mainAction = actionFunction
       return this
     },
+
     post() {
       return this
     },
+
     run(payload, dependencies) {
       return (
         preActions
           // we work with promises because this allows us easy capture all the async stuff
           .reduce((acc, v) => acc.then(r => (v.func(r), r)), Promise.resolve({ payload, dependencies }))
-          .then
           // do action now will work with pre
-          ()
-          .then
-          // do post actions
-          ()
+          .then(({ payload, dependencies }) => mainAction(payload, dependencies))
       )
     }
   }

packages/sls-app/tests/index.test.ts

@@ -0,0 +1,60 @@
+import { application, ApplicationError } from '../src'
+
+describe('application flow', () => {
+  describe('action', () => {
+    it('creates an application with an action only', () =>
+      application<string, { appendString: string }, string>()
+        .action((payload, { appendString }) => `${payload} ${appendString}`)
+        .run('hello', { appendString: 'world' })
+        .then(result => {
+          expect(result).toBe('hello world')
+        }))
+
+    it('throws an error when multiple actions are created', () =>
+      expect(() =>
+        application<string, { appendString: string }, string>()
+          .action((payload, { appendString }) => `${payload} ${appendString}`)
+          .action((payload, { appendString }) => `${payload} ${appendString}`)
+          .run('hello', { appendString: 'world' })
+      ).toThrowError(new ApplicationError('you can only have a single action')))
+  })
+
+  describe('pre action', () => {
+    it('execute pre action before main action', async () => {
+      const preAction = jest.fn()
+      const action = jest.fn()
+
+      return application<string, { appendString: string }, void>()
+        .pre(preAction)
+        .action(action)
+        .run('hello', { appendString: 'world' })
+        .then(() => {
+          expect(preAction).toHaveBeenCalledWith({ payload: 'hello', dependencies: { appendString: 'world' } })
+          expect(action).toHaveBeenCalledWith('hello', { appendString: 'world' })
+          //@ts-ignore
+          expect(preAction).toHaveBeenCalledBefore(action)
+        })
+    })
+
+    it('executes pre actions in order of definition', async () => {
+      const preAction1 = jest.fn()
+      const preAction2 = jest.fn()
+      const action = jest.fn()
+
+      return application<string, { appendString: string }, void>()
+        .pre(preAction1)
+        .pre(preAction2)
+        .action(action)
+        .run('hello', { appendString: 'world' })
+        .then(() => {
+          expect(preAction1).toHaveBeenCalledWith({ payload: 'hello', dependencies: { appendString: 'world' } })
+          expect(preAction2).toHaveBeenCalledWith({ payload: 'hello', dependencies: { appendString: 'world' } })
+          expect(action).toHaveBeenCalledWith('hello', { appendString: 'world' })
+          //@ts-ignore
+          expect(preAction1).toHaveBeenCalledBefore(preAction2)
+          //@ts-ignore
+          expect(preAction2).toHaveBeenCalledBefore(action)
+        })
+    })
+  })
+})

packages/sls-app/tsconfig.json

@@ -4,6 +4,6 @@
     "outDir": "./dist",
     "declaration": true
   },
-  "include": ["src/**/*"],
+  "include": ["src/**/*", "tests/**/*"],
   "exclude": ["dist/**/*"]
 }

packages/sls-env/jest.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  setupFilesAfterEnv: ['jest-extended']
+}

packages/sls-env/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "@cabiri-io/sls-env",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "MIT",
+  "scripts": {
+    "test": "jest"
+  },
+  "devDependencies": {
+    "@types/jest": "^26.0.0",
+    "jest": "^26.0.1",
+    "jest-extended": "^0.11.5",
+    "ts-jest": "^26.1.0",
+    "typescript": "^3.9.5"
+  }
+}

packages/sls-env/tests/index.test.js

@@ -0,0 +1 @@
+describe('serverless environment', () => {})

packages/sls-env/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "declaration": true
+  },
+  "include": ["src/**/*", "tests/**/*"],
+  "exclude": ["dist/**/*"]
+}