Benchmark: isUTCDateTimeMs - MeasureThat.net

Script Preparation code:

var n = 1000;
var testValues = [...Array(n)].map((_, i) => {
  if (Math.random() < 0.5) {
    const d = new Date();
    d.setMilliseconds(i);
    return d.toISOString();
  }
  return (Math.random() + 1).toString(36).substring(2);
});

/**
 *
 */
function isUTCDateTimeMs(value) {
  if (typeof value !== "string") {
    return false;
  }

  const parsed = new Date(value);
  if (Number.isNaN(parsed.getTime())) {
    return false;
  }

  return value === parsed.toISOString();
}

/**
 *
 */
function isUTCDateTimeMsDayJsy(value) {
  if (typeof value !== "string") {
    return false;
  }

  const parsed = new Date(value);
  if (parsed.toString() === "Invalid Date") {
    return false;
  }

  return value === parsed.toISOString();
}

/**
 *
 */
function isUTCDateTimeMsParse(value) {
  if (typeof value !== "string") {
    return false;
  }

  const parsed = Date.parse(value);
  if (Number.isNaN(parsed)) {
    return false;
  }

  const d = new Date(parsed);

  return value === d.toISOString();
  // try {
  //   return value === new Date(value).toISOString();
  // } catch (err) {
  //   return false;
  // }
}

/**
 *
 */
function isUTCDateTimeMsTryCatch(value) {
  if (typeof value !== "string") {
    return false;
  }

  try {
    return value === new Date(value).toISOString();
  } catch (err) {
    return false;
  }
}

Tests:

isUTCDateTimeMs
/// let r = 0; for (const t of testValues) { r += +isUTCDateTimeMs(t); }
isUTCDateTimeMsDayJsy
/// let r = 0; for (const t of testValues) { r += +isUTCDateTimeMsDayJsy(t); }
isUTCDateTimeMsParse
/// let r = 0; for (const t of testValues) { r += +isUTCDateTimeMsParse(t); }
isUTCDateTimeMsTryCatch
/// let r = 0; for (const t of testValues) { r += +isUTCDateTimeMsTryCatch(t); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isUTCDateTimeMs
isUTCDateTimeMsDayJsy
isUTCDateTimeMsParse
isUTCDateTimeMsTryCatch

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
isUTCDateTimeMs	2329.0 Ops/sec
isUTCDateTimeMsDayJsy	1478.6 Ops/sec
isUTCDateTimeMsParse	2202.6 Ops/sec
isUTCDateTimeMsTryCatch	508.8 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition JSON**

The provided benchmark definition JSON defines four test cases: `isUTCDateTimeMs`, `isUTCDateTimeMsDayJsy`, `isUTCDateTimeMsParse`, and `isUTCDateTimeMsTryCatch`. These functions are designed to determine whether a given string value represents a UTC date and time in milliseconds.

**Test Cases**

Here's a brief explanation of each test case:

1. `isUTCDateTimeMs`: This function checks if the input value is equal to the parsed ISO date string representation of a Date object.
2. `isUTCDateTimeMsDayJsy`: Similar to the previous one, but this function uses the `toString()` method to check if the input value matches the original date string.
3. `isUTCDateTimeMsParse`: This function attempts to parse the input value using the `Date.parse()` method and then checks if it matches the original date string.
4. `isUTCDateTimeMsTryCatch`: This function uses a try-catch block to attempt parsing the input value as a Date object and then checks if it matches the original date string.

**Options Compared**

The test cases compare different approaches to parsing and checking UTC date strings:

* **Direct Comparison**: `isUTCDateTimeMs` and `isUTCDateTimeMsDayJsy` use direct comparison with the ISO date string representation.
* **Parsing and Comparison**: `isUTCDateTimeMsParse` uses `Date.parse()` to parse the input value, which can be more efficient but also introduces potential errors.
* **Try-Catch Block**: `isUTCDateTimeMsTryCatch` uses a try-catch block to attempt parsing the input value as a Date object, which provides additional error handling.

**Pros and Cons**

Here's a brief analysis of each approach:

1. **Direct Comparison**:
	* Pros: Simple, efficient, and accurate.
	* Cons: May not work correctly for malformed or invalid input values.
2. **Parsing and Comparison**:
	* Pros: Can handle malformed input values by returning false.
	* Cons: May introduce errors if the `Date.parse()` method fails, which can happen with certain invalid inputs.
3. **Try-Catch Block**:
	* Pros: Provides additional error handling and protection against parsing errors.
	* Cons: May introduce performance overhead due to the try-catch block.

**Other Considerations**

When running these benchmarks, it's essential to consider factors like:

* Input value quality: Are input values well-formatted and valid?
* Browser support: Will the benchmark results be accurate across different browsers and versions?
* Performance optimization: Are there opportunities to optimize the code for better performance?

**Alternatives**

If you're interested in exploring alternative approaches, you can consider:

1. Using a dedicated date parsing library like Moment.js or Luxon.
2. Implementing custom date parsing logic using regular expressions or other techniques.
3. Using a more advanced JavaScript feature like `Intl.DateTimeFormat` to parse and format dates.

Keep in mind that these alternatives may introduce additional complexity, dependencies, or performance overhead.

I hope this helps you understand the world of JavaScript microbenchmarks!

Related benchmarks:

isUTCDateTimeMs (version: 0)

isUTCDateTimeMsTryCatch

Comparing performance of: isUTCDateTimeMs vs isUTCDateTimeMsDayJsy vs isUTCDateTimeMsParse vs isUTCDateTimeMsTryCatch

Created: one year ago by: Guest

Jump to the latest result

isUTCDateTimeMs

isUTCDateTimeMsDayJsy

isUTCDateTimeMsParse

isUTCDateTimeMsTryCatch

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):