Let's dive into the world of JavaScript microbenchmarks and explore what's being tested on MeasureThat.net.

The benchmark definition JSON represents two test cases:

Script Preparation Code

var a = 0;
function f() {
  a += 0.01;
  if (a < 0) {
    throw new Error();
  }
}

This code defines a function f() that increments a variable a by 0.01 every time it's called. If a ever becomes negative, an error is thrown.

Options being compared

The benchmark compares two approaches:

1. Plain execution: The test simply calls the f() function without any try-catch block.
2. Try-catch execution: The test wraps the call to f() in a try-catch block, which catches and logs any errors thrown by the function.

Pros and Cons

• Plain execution:
  • Pros: Simpler, less overhead due to error handling.
  • Cons: May not accurately represent real-world scenarios where exceptions are thrown.
• Try-catch execution:
  • Pros: More realistic, as try-catch blocks are commonly used in JavaScript to handle errors.
  • Cons: Adds overhead due to the extra logic for catching and logging errors.

Library usage

There is no explicit library mentioned in the benchmark definition. However, it's likely that MeasureThat.net uses a hidden library or framework to execute the benchmarks and provide the results.

Special JS features/syntax

None are explicitly mentioned. The code uses standard JavaScript syntax and features.

Now, let's look at the individual test cases:

• plain: This test case calls the f() function without any try-catch block.
• try catch: This test case wraps the call to f() in a try-catch block, which catches and logs any errors thrown by the function.

Other alternatives

Some alternative approaches could be explored, such as:

1. No-op execution: Instead of calling the f() function, simply execute some no-op code (e.g., a constant value) to test the function's overhead.
2. Loop-based execution: Call the f() function in a loop to simulate repeated executions and measure the overhead.
3. Async execution: Use async/await or Promises to test the function's behavior under asynchronous conditions.

These alternative approaches might provide additional insights into the performance characteristics of the f() function, but they would require modifications to the benchmark definition and execution code.

That's a summary of what's being tested on MeasureThat.net!