feat: added get()

Author: webdeveric

src/get.ts

@@ -0,0 +1,32 @@
+import { pathParts } from './pathParts.js';
+
+import type { Path, PathValue } from './types/objects.js';
+
+export function get<Input extends object, const InputPath extends Path<Input>>(
+  input: Input,
+  path: InputPath,
+): PathValue<Input, InputPath>;
+
+export function get<const Input extends object, const InputPath extends string>(input: Input, path: InputPath): unknown;
+
+export function get<const Input extends object, const InputPath extends Path<Input> | string>(
+  input: Input,
+  path: InputPath,
+): unknown {
+  if (path === '') {
+    return input;
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  let current: any = input;
+
+  for (const part of pathParts(path)) {
+    if (typeof current === 'object' && current !== null && part in current) {
+      current = current[part];
+    } else {
+      return;
+    }
+  }
+
+  return current;
+}

src/index.ts

@@ -23,6 +23,7 @@ export * from './delayAnimationFrame.js';
 export * from './delayAnimationFrames.js';
 export * from './describeInput.js';
 export * from './escapeRegExp.js';
+export * from './get.js';
 export * from './getDateString.js';
 export * from './getISODateString.js';
 export * from './getMaxValue.js';

test/get.test.ts

@@ -0,0 +1,54 @@
+import { describe, it, expect } from 'vitest';
+
+import { get } from '../src/get.js';
+
+describe('get()', () => {
+  const input = {
+    age: 100_000,
+    name: {
+      first: 'Test',
+      last: 'Testerson',
+    },
+    sayHi(): void {
+      console.log('Hi!');
+    },
+    role: [
+      {
+        job: {
+          title: 'Developer',
+        },
+      },
+    ],
+  };
+
+  it('returns a value from an object', () => {
+    const lastName = get(input, 'name.last');
+    const jobTitle = get(input, 'role.0.job.title');
+
+    expect(lastName).toBe(input.name.last);
+    expect(jobTitle).toBe(input.role[0]?.job.title);
+  });
+
+  it('Returns undefined when path is invalid', () => {
+    const result = get(input, 'role.0.job.nonExistent');
+
+    expect(result).toBeUndefined();
+  });
+
+  it('Handles built in objects', () => {
+    const date = new Date();
+
+    const result = get(date, 'toString');
+
+    // eslint-disable-next-line @typescript-eslint/unbound-method
+    expect(result).toBe(date.toString);
+  });
+
+  it('Empty path returns input', () => {
+    const date = new Date();
+
+    const result = get(date, '');
+
+    expect(result).toBe(date);
+  });
+});