Please review the following code snippet. If there are areas for improvement
based on best practices, logic errors, repetition,
or optimization, please provide suggestions.

Please review the following code snippet.
If there are areas for improvement based on best practices,
logic errors, repetition, or optimization, please provide suggestions.

function factorial(n) {
	if (n < 0) {
		throw new Error("Factorial is not defined for negative numbers.");
	}
	let result = 1;
	for (let i = 2; i <= n; i++) {
		result *= i;
	}
	return result;
}

function factorial(n) {
  if (n < 0 || !Number.isInteger(n)) {
    throw new Error("Please provide a non-negative integer.")
  }

  let result = 1
  for (let i = 2; i <= n; i++) {
    result *= i
  }
  return result
}

Your code snippet for calculating the factorial of a number looks good and will produce correct results for non-negative integers. However, there are a few points I'd like to touch upon:

# Input validation:
If n is not an integer, your function will still try to calculate the factorial. For instance, factorial(5.5) will run without error but produce an unexpected result. It might be a good idea to validate if n is an integer.

# Recursive approach:
Some might argue that a recursive approach is more "elegant" or intuitive for factorials. However, be aware that the recursive approach will hit a stack limit with larger values of n. Your iterative approach doesn't have this problem, so it's often more efficient and can handle bigger numbers. Still, if you'd like a sample of the recursive approach:

# Handling larger numbers:
JavaScript numbers can get imprecise with very large values. If you want to handle larger factorials, you might want to use a library like BigInteger to handle the arithmetic operations.

# Input validation for integers:

You can add a condition to check if n is an integer.

You are a specialized code documentation assistant. Given the following function,
please provide a detailed explanation in Markdown format suitable for a README.md file.
This should include the function's purpose, usage, and illustrative examples.

### factorial Function

**Purpose**
The factorial function calculates the factorial of a given non-negative integer.
In mathematics, the factorial of a non-negative integer n is the product of all
positive integers less than or equal to n. It is denoted by n!.

### Usage

#### Parameters

- n (Number): The non-negative integer for which the factorial is to be calculated.
  Returns
- (Number): The factorial of the given number n.
  Throws
- Error: If the provided number n is negative or not an integer.
  **Example: **

```javascript
// Using the factorial function
const result = factorial(5) // Returns 120 because 5! = 5 x 4 x 3 x 2 x 1 = 120
console.log(result) // Outputs: 120

const anotherResult = factorial(0) // Returns 1 because 0! is defined as 1
console.log(anotherResult) // Outputs: 1

// Providing a negative number or a non-integer will throw an error
try {
  const errorResult = factorial(-5)
} catch (error) {
  console.error(error.message) // Outputs: "Please provide a non-negative integer."
}

try {
  const errorResult = factorial(5.5)
} catch (error) {
  console.error(error.message) // Outputs: "Please provide a non-negative integer."
}
```

### Implementation Details

The function starts by checking if the provided number n is negative or not an integer. If either of these conditions is true, it throws an error. Otherwise, it initializes a result variable to 1 and then multiplies it by every integer from 2 to n using a for loop. The final result is then returned.

You are a Jest testing expert. Given the following JavaScript function,
please provide a comprehensive set of Jest test cases to ensure its correctness.
Include necessary imports, describe blocks, and test cases.

// Test suite for the factorial function
describe("factorial", () => {
  // Test cases for valid inputs
  it("should return 1 for n=0", () => {
    expect(factorial(0)).toBe(1)
  })

  it("should return 1 for n=1", () => {
    expect(factorial(1)).toBe(1)
  })

  it("should return 2 for n=2", () => {
    expect(factorial(2)).toBe(2)
  })

  it("should return 6 for n=3", () => {
    expect(factorial(3)).toBe(6)
  })

  it("should return 24 for n=4", () => {
    expect(factorial(4)).toBe(24)
  })

  // Test cases for invalid inputs
  it("should throw an error for negative numbers", () => {
    expect(() => factorial(-1)).toThrow("Please provide a non-negative integer.")
  })

  it("should throw an error for non-integer numbers", () => {
    expect(() => factorial(2.5)).toThrow("Please provide a non-negative integer.")
  })

  it("should throw an error for non-number types", () => {
    expect(() => factorial("string")).toThrow("Please provide a non-negative integer.")
    expect(() => factorial({})).toThrow("Please provide a non-negative integer.")
    expect(() => factorial([])).toThrow("Please provide a non-negative integer.")
    expect(() => factorial(true)).toThrow("Please provide a non-negative integer.")
  })
})

You are a naming expert. Given the following description of a variable's purpose and context, please suggest a concise and descriptive variable name.

Given the context and purpose of the variable, which is to store the result of the factorial function, a more descriptive name for the variable would be:

let factorialResult = factorial(5);
This name clearly indicates that the variable holds the result of a factorial computation.

You are a troubleshooting expert. I've encountered the following error while working on my codebase.
Here's the error message and context:

*********[Error message and any relevant code or logs]*********

Can you provide an 1. an explanation
and 2. a solution or suggest steps to resolve this issue?