feat(engine-server): Add parameter check to renderComponent (salesforce#1964)

pmdartus · web-flow · commit c273973b93d6 · 2020-07-07T15:30:34.000+02:00
diff --git a/packages/@lwc/engine-server/src/__tests__/render-component.spec.ts b/packages/@lwc/engine-server/src/__tests__/render-component.spec.ts
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2020, salesforce.com, inc.
+ * All rights reserved.
+ * SPDX-License-Identifier: MIT
+ * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
+ */
+
+import { renderComponent, LightningElement } from '../index';
+
+class Test extends LightningElement {}
+
+describe('renderComponent', () => {
+    it('returns the rendered tree as string', () => {
+        expect(renderComponent('x-test', Test)).toBe(
+            '<x-test><template shadow-root></template></x-test>'
+        );
+    });
+
+    it.each([undefined, null, 1, {}, () => {}])(
+        'asserts the first parameter is a string (type: %p)',
+        (value) => {
+            expect(() => renderComponent(value as any, Test, {})).toThrow(
+                `"renderComponent" expects a string as the first parameter but instead received ${value}.`
+            );
+        }
+    );
+
+    it.each([undefined, null, 1, 'test', {}])(
+        'asserts the seconds parameter is a function (type: %p)',
+        (value) => {
+            expect(() => renderComponent('x-test', value as any, {})).toThrow(
+                `"renderComponent" expects a valid component constructor as the second parameter but instead received ${value}.`
+            );
+        }
+    );
+
+    it.each([null, 1, 'test', () => {}])(
+        'asserts the third parameter is an object (type: %p)',
+        (value) => {
+            expect(() => renderComponent('x-test', Test, value as any)).toThrow(
+                `"renderComponent" expects an object as the third parameter but instead received ${value}.`
+            );
+        }
+    );
+});
diff --git a/packages/@lwc/engine-server/src/apis/render-component.ts b/packages/@lwc/engine-server/src/apis/render-component.ts
@@ -11,15 +11,34 @@ import {
     setElementProto,
     LightningElement,
 } from '@lwc/engine-core';
+import { isString, isFunction, isObject, isNull } from '@lwc/shared';
 
 import { renderer } from '../renderer';
 import { serializeElement } from '../serializer';
 
 export function renderComponent(
     tagName: string,
     Ctor: typeof LightningElement,
-    props: { [name: string]: any }
+    props: { [name: string]: any } = {}
 ): string {
+    if (!isString(tagName)) {
+        throw new TypeError(
+            `"renderComponent" expects a string as the first parameter but instead received ${tagName}.`
+        );
+    }
+
+    if (!isFunction(Ctor)) {
+        throw new TypeError(
+            `"renderComponent" expects a valid component constructor as the second parameter but instead received ${Ctor}.`
+        );
+    }
+
+    if (!isObject(props) || isNull(props)) {
+        throw new TypeError(
+            `"renderComponent" expects an object as the third parameter but instead received ${props}.`
+        );
+    }
+
     const element = renderer.createElement(tagName);
 
     const def = getComponentInternalDef(Ctor);
