Merge pull request cerebral#90 from cerebral/constructorCheck

feat(action-chain): warn about constructor instantiation

Author: christianalfoni

packages/node_modules/action-chain/src/index.test.ts

@@ -65,6 +65,7 @@ const context = {
         return 'baz'
       },
     },
+    Constr: TestProvider,
   },
   test: new TestProvider(),
 }
@@ -185,6 +186,27 @@ describe('EFFECTS', () => {
     })
     fn()
   })
+  test('should track execution of constructor instantiation', () => {
+    expect.assertions(3)
+    const fn = action().test(({ foo }) => {
+      const instance = new foo.Constr()
+      expect(instance.foo()).toBe('bar')
+      expect(instance).toBeInstanceOf(TestProvider)
+    })
+
+    actionChain.once('effect', (task) => {
+      expect(task).toEqual({
+        operatorId: 0,
+        actionId: 0,
+        executionId: 0,
+        method: 'Constr',
+        args: [],
+        name: 'foo',
+        result: '[Constr]',
+      })
+    })
+    fn()
+  })
 })
 
 describe('ACTION CHAIN', () => {

packages/node_modules/action-chain/src/utils.ts

@@ -6,13 +6,15 @@ function isObject(value) {
   return typeof value === 'object' && !Array.isArray(value) && value !== null
 }
 
+let hasWarnedConstructor = false
+
 function createProxyGetHandler(
   path: string,
   cb: (effect: EffectResult) => void
 ): ProxyHandler<any>['get'] {
   return (target, prop) => {
     if (typeof target[prop] === 'function') {
-      return function(...args) {
+      const func = function(...args) {
         const result = target[prop].apply(this, args)
         if (result instanceof Promise) {
           result.then((promisedResult) => {
@@ -35,6 +37,27 @@ function createProxyGetHandler(
         }
         return result
       }
+
+      return new Proxy(func, {
+        construct(_, args) {
+          // eslint-disable-next-line
+          cb({
+            name: path,
+            method: prop,
+            args,
+            result: `[${prop.toString()}]`,
+          })
+
+          if (!hasWarnedConstructor) {
+            console.warn(
+              `EFFECTS - It is highly recommended to create a custom effect, exposing a method that deals with the instantiation of "${path}.${prop.toString()}". It improves readability and debugability of your app`
+            )
+            hasWarnedConstructor = true
+          }
+
+          return new target[prop](...args)
+        },
+      })
     }
     if (isObject(target[prop])) {
       return new Proxy(target[prop], {