fix: restore insist (#759)

Author: TobiTenno

test/utilities/integrity.spec.ts

@@ -0,0 +1,26 @@
+import { should } from 'chai';
+import { insist } from '../../tools/integrity';
+
+should();
+
+describe('integrity', () => {
+  it('should throw TypeError when required property is missing', () => {
+    (() => insist({}, 'a')).should.throw(TypeError);
+    (() => insist({ a: 1 }, 'a', 'b')).should.throw(TypeError);
+  });
+  it('should not throw when all required properties are present', () => {
+    (() => insist({ a: 1, b: 2 }, 'a', 'b')).should.not.throw();
+  });
+  it('should allow falsy values (0, false, \'\') as property values', () => {
+    (() => insist({ a: 0 }, 'a')).should.not.throw();
+    (() => insist({ a: false }, 'a')).should.not.throw();
+    (() => insist({ a: '' }, 'a')).should.not.throw();
+  });
+  it('should throw when object is null or undefined', () => {
+    (() => insist(null as unknown as Record<string, unknown>, 'a')).should.throw();
+    (() => insist(undefined as unknown as Record<string, unknown>, 'a')).should.throw();
+  });
+  it('should not throw when no properties are required', () => {
+    (() => insist({ a: 0 })).should.not.throw();
+  });
+});

tools/integrity.ts

@@ -0,0 +1,16 @@
+/**
+ * @description Insist that the provided data has the required properties.
+ * @param {Record<string, unknown>} thing to encourage to have data
+ * @param {...string} args arguments to ensure
+ */
+export const insist = (thing: Record<string, unknown>, ...args: string[]) => {
+  if (!thing || !Object.keys(thing).length) {
+    throw new TypeError('No data provided.');
+  }
+
+  args.forEach((arg) => {
+    if (!(arg in thing)) {
+      throw new TypeError(`Missing required property: '${arg}'.`);
+    }
+  });
+};

tools/utilities.ts

@@ -1,4 +1,5 @@
 /* istanbul ignore file */
 
+export * from './integrity';
 export * from './timeDate';
 export * from './translation';