#8

Author: mavarazy

src/Engine.js

@@ -1,22 +1,35 @@
-import { validatePredicates, validateConditionFields } from "./validation";
+import { validateConditionFields, validatePredicates } from "./validation";
 import applicableActions from "./applicableActions";
-import { isDevelopment, isObject, toError } from "./utils";
+import { isDevelopment, isObject, toArray, toError } from "./utils";
+
+const validate = schema => {
+  let isSchemaDefined = schema !== undefined && schema !== null;
+  if (isDevelopment() && isSchemaDefined) {
+    if (!isObject(schema)) {
+      toError(`Expected valid schema object, but got - ${schema}`);
+    }
+    return rule => {
+      validatePredicates([rule.conditions], schema);
+      validateConditionFields([rule.conditions], schema);
+    };
+  } else {
+    return () => {};
+  }
+};
 
 class Engine {
   constructor(rules, schema) {
-    this.rules = rules;
-    if (isDevelopment()) {
-      let conditions = rules.map(rule => rule.conditions);
-      if (schema !== undefined && schema !== null) {
-        if (isObject(schema)) {
-          validatePredicates(conditions, schema);
-          validateConditionFields(conditions, schema);
-        } else {
-          toError(`Expected valid schema object, but got - ${schema}`);
-        }
-      }
+    this.rules = [];
+    this.validate = validate(schema);
+
+    if (rules) {
+      toArray(rules).forEach(rule => this.addRule(rule));
     }
   }
+  addRule = rule => {
+    this.validate(rule);
+    this.rules.push(rule);
+  };
   run = formData => Promise.resolve(applicableActions(this.rules, formData));
 }
 

test/Engine.test.js

@@ -51,3 +51,11 @@ test("age less 70 ", () => {
 test("age greater 70 ", () => {
   return engine.run({ age: 71 }).then(actions => expect(actions).toEqual([]));
 });
+
+test("empty engine creation", () => {
+  expect(new Engine()).not.toBeUndefined();
+  expect(new Engine(undefined)).not.toBeUndefined();
+  expect(new Engine(null)).not.toBeUndefined();
+  expect(new Engine([])).not.toBeUndefined();
+  expect(new Engine(rules[0])).not.toBeUndefined();
+});