Benchmark Overview

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided JSON represents a benchmark with three test cases, each testing a different approach to creating an object by spreading or assigning properties from two source objects.

Test Case 1: Basic Object Spread

The first test case measures the performance of creating an object using the spread operator ({...obj2, ...obj}).

const obj = { foo: 1, bar: 2 };
const obj2 = { baz: 3 };
const finalObject = ({...obj2, ...obj});

Pros and Cons

• Pros: The spread operator is a concise and readable way to create an object by spreading properties from multiple sources.
• Cons: The performance of this approach may vary depending on the number of properties being spread.

Test Case 2: Basic Assign Operator

The second test case measures the performance of creating an object using the assignment operator (Object.assign(obj2, obj)).

const obj = { foo: 1, bar: 2 };
const obj2 = { baz: 3 };
const finalObject = Object.assign(obj2, obj);

Pros and Cons

• Pros: The assignment operator is a widely supported and efficient way to create an object by assigning properties from multiple sources.
• Cons: This approach may require additional setup (e.g., checking if obj and obj2 are objects) to ensure correct behavior.

Test Case 3: Assign with Empty Object

The third test case measures the performance of creating an object using the assignment operator with an empty object (Object.assign({}, obj, obj2)).

const obj = { foo: 1, bar: 2 };
const obj2 = { baz: 3 };
Object.assign({}, obj, obj2);

Pros and Cons

• Pros: This approach is useful when creating an object from multiple sources with different lengths.
• Cons: The performance of this approach may be slower due to the overhead of creating an empty object.

Library Used: None

None of the test cases use any libraries, making them self-contained and easy to understand.

Special JS Features or Syntax: None

The benchmark does not use any special JavaScript features or syntax beyond what is standard in modern JavaScript.

Other Alternatives

Alternative approaches to creating objects could include:

1. Using Object.create() method
2. Using a library like Lodash's cloneDeep() function
3. Using a template literal with the spread operator ({...obj, ...obj2})

However, these alternatives are not tested in this benchmark, and their performance may vary depending on specific use cases.

Benchmark Preparation Code: None

The provided JSON does not include any preparation code for setting up the test environment or loading dependencies.