From 08421d37cfc95bc5bbc34d809937bbfa74ea10e8 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Fri, 10 Apr 2020 00:11:41 +0300
Subject: [PATCH] feat: add context strategies

---
 .../src/lib/strategies/context.strategy.ts    | 47 +++++++++++
 .../packages/core/src/lib/strategies/index.ts |  1 +
 .../src/lib/tests/context.strategy.spec.ts    | 79 +++++++++++++++++++
 3 files changed, 127 insertions(+)
 create mode 100644 npm/ng-packs/packages/core/src/lib/strategies/context.strategy.ts
 create mode 100644 npm/ng-packs/packages/core/src/lib/tests/context.strategy.spec.ts

diff --git a/npm/ng-packs/packages/core/src/lib/strategies/context.strategy.ts b/npm/ng-packs/packages/core/src/lib/strategies/context.strategy.ts
new file mode 100644
index 0000000000..e3d16c0573
--- /dev/null
+++ b/npm/ng-packs/packages/core/src/lib/strategies/context.strategy.ts
@@ -0,0 +1,47 @@
+import { ComponentRef, TemplateRef, Type } from '@angular/core';
+import { InferedContextOf, InferedInstanceOf } from '../models';
+
+export abstract class ContextStrategy<T = any> {
+  constructor(public context: Partial<ContextType<T>>) {}
+
+  /* tslint:disable-next-line:no-unused-variable */
+  setContext(componentRef?: ComponentRef<InferedInstanceOf<T>>): Partial<ContextType<T>> {
+    return this.context;
+  }
+}
+
+export class NoContextStrategy<
+  T extends Type<any> | TemplateRef<any> = any
+> extends ContextStrategy<T> {
+  constructor() {
+    super(undefined);
+  }
+}
+
+export class ComponentContextStrategy<T extends Type<any> = any> extends ContextStrategy<T> {
+  setContext(componentRef: ComponentRef<InferedInstanceOf<T>>): Partial<InferedInstanceOf<T>> {
+    Object.keys(this.context).forEach(key => (componentRef.instance[key] = this.context[key]));
+    componentRef.changeDetectorRef.detectChanges();
+    return this.context;
+  }
+}
+
+export class TemplateContextStrategy<T extends TemplateRef<any> = any> extends ContextStrategy<T> {
+  setContext(): Partial<InferedContextOf<T>> {
+    return this.context;
+  }
+}
+
+export const CONTEXT_STRATEGY = {
+  None<T extends Type<any> | TemplateRef<any> = any>() {
+    return new NoContextStrategy<T>();
+  },
+  Component<T extends Type<any> = any>(context: Partial<InferedInstanceOf<T>>) {
+    return new ComponentContextStrategy<T>(context);
+  },
+  Template<T extends TemplateRef<any> = any>(context: Partial<InferedContextOf<T>>) {
+    return new TemplateContextStrategy<T>(context);
+  },
+};
+
+type ContextType<T> = T extends Type<infer U> | TemplateRef<infer U> ? U : never;
diff --git a/npm/ng-packs/packages/core/src/lib/strategies/index.ts b/npm/ng-packs/packages/core/src/lib/strategies/index.ts
index 2d6be484dd..28447748f7 100644
--- a/npm/ng-packs/packages/core/src/lib/strategies/index.ts
+++ b/npm/ng-packs/packages/core/src/lib/strategies/index.ts
@@ -1,5 +1,6 @@
 export * from './content-security.strategy';
 export * from './content.strategy';
+export * from './context.strategy';
 export * from './cross-origin.strategy';
 export * from './dom.strategy';
 export * from './loading.strategy';
diff --git a/npm/ng-packs/packages/core/src/lib/tests/context.strategy.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/context.strategy.spec.ts
new file mode 100644
index 0000000000..461c397457
--- /dev/null
+++ b/npm/ng-packs/packages/core/src/lib/tests/context.strategy.spec.ts
@@ -0,0 +1,79 @@
+import { ComponentRef } from '@angular/core';
+import {
+  ComponentContextStrategy,
+  CONTEXT_STRATEGY,
+  NoContextStrategy,
+  TemplateContextStrategy,
+} from '../strategies';
+import { uuid } from '../utils';
+
+describe('ComponentContextStrategy', () => {
+  describe('#setContext', () => {
+    let componentRef: ComponentRef<any>;
+
+    beforeEach(
+      () =>
+        (componentRef = {
+          instance: {
+            x: '',
+            y: '',
+            z: '',
+          },
+          changeDetectorRef: {
+            detectChanges: jest.fn(),
+          },
+        } as any),
+    );
+
+    test.each`
+      props              | values
+      ${['x']}           | ${[uuid()]}
+      ${['x', 'y']}      | ${[uuid(), uuid()]}
+      ${['x', 'y', 'z']} | ${[uuid(), uuid(), uuid()]}
+    `(
+      'should set $props as $values and call detectChanges once',
+      ({ props, values }: { props: string[]; values: string[] }) => {
+        const context = {};
+        props.forEach((prop, i) => {
+          context[prop] = values[i];
+        });
+
+        const strategy = new ComponentContextStrategy(context);
+        strategy.setContext(componentRef);
+
+        expect(props.every(prop => componentRef.instance[prop] === context[prop])).toBe(true);
+        expect(componentRef.changeDetectorRef.detectChanges).toHaveBeenCalledTimes(1);
+      },
+    );
+  });
+});
+
+describe('NoContextStrategy', () => {
+  describe('#setContext', () => {
+    it('should return undefined', () => {
+      const strategy = new NoContextStrategy();
+      expect(strategy.setContext(null)).toBeUndefined();
+    });
+  });
+});
+
+describe('TemplateContextStrategy', () => {
+  describe('#setContext', () => {
+    it('should return context', () => {
+      const context = { x: uuid() };
+      const strategy = new TemplateContextStrategy(context);
+      expect(strategy.setContext()).toEqual(context);
+    });
+  });
+});
+
+describe('CONTEXT_STRATEGY', () => {
+  test.each`
+    name           | Strategy
+    ${'Component'} | ${ComponentContextStrategy}
+    ${'None'}      | ${NoContextStrategy}
+    ${'Template'}  | ${TemplateContextStrategy}
+  `('should successfully map $name to $Strategy.name', ({ name, Strategy }) => {
+    expect(CONTEXT_STRATEGY[name](undefined)).toEqual(new Strategy(undefined));
+  });
+});