method Assert.prototype.deepEqual Assert.prototype.deepEqual(actual: unknown,expected: unknown,message?: string): void Asserts deep equality between actual and expected using recursive structural comparison. Handles nested objects, arrays, Date, RegExp, and more. Examples Example 1 assert.deepEqual([1, { a: 2 }], [1, { a: 2 }]); assert.deepEqual(new Date("2024-01-01"), new Date("2024-01-01")); Parameters actual: unknown The actual value. expected: unknown The expected value. optional message: string Optional failure message. Return Type void