Benchmark Tests in Golang

This is a benchmark codebase accompanying a blog post about benchmarking in Golang.

The codebase contains a formatter package that formats a string by replacing all occurrences of a given substring with another string. To see the Benchmark code, check out the formatter/formatter_test.go file. However, you should read the accompany blog post to have better understanding of the benefits of benchmarking your code.

My Benchmark Results

Results of running the benchmarks on my computer (M2 Pro, 16GB):

BenchmarkNormalise/WithReplacer-10              50672794               228.3 ns/op            32 B/op          2 allocs/op
BenchmarkNormalise/WithReplacer-10              52982422               229.2 ns/op            32 B/op          2 allocs/op
BenchmarkNormalise/WithReplacer-10              52576513               228.2 ns/op            32 B/op          2 allocs/op
BenchmarkNormalise/WithReplacer-10              52496136               228.9 ns/op            32 B/op          2 allocs/op
BenchmarkNormalise/WithReplacer-10              52274142               229.7 ns/op            32 B/op          2 allocs/op
BenchmarkNormalise/WithRegexp-10                26651758               451.6 ns/op            56 B/op          4 allocs/op
BenchmarkNormalise/WithRegexp-10                26442408               452.4 ns/op            56 B/op          4 allocs/op
BenchmarkNormalise/WithRegexp-10                26480550               452.6 ns/op            56 B/op          4 allocs/op
BenchmarkNormalise/WithRegexp-10                26595258               453.2 ns/op            56 B/op          4 allocs/op
BenchmarkNormalise/WithRegexp-10                26478879               452.6 ns/op            56 B/op          4 allocs/op

Clearly the WithReplacer version is faster by about 50% (even though the WithReplacer still does a matcher check). Another reason why you should be careful when using regex.

Running the benchmarks

To run the benchmarks, use the following command:

go test -bench . -count 5 -benchmem  -benchtime 10s ./...

This will run all benchmarks in the codebase and print out the results, including memory allocations.

Feel free to use this codebase as a reference for your own benchmarking needs. If you have any questions or suggestions, please feel free to open an issue or a pull request.