Do not load unnecessary package information

[samherrmann]

This merge request is a performance improvement to address #178. The merge request contains two commits, in which the first commit adds a benchmark test. This allows the benchmark test to be executed before and after the changes in the second commit for comparison. Further optimization may be required to close #178, but I hope that this merge request is a step in the right direction.

The following are the benchmark results on my dev machine:

Before:

$ go test -bench=. ./internal/registry -count 3
goos: linux
goarch: amd64
pkg: github.com/matryer/moq/internal/registry
cpu: Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz
BenchmarkNew-8                 3         335638233 ns/op
BenchmarkNew-8                 4         328678100 ns/op
BenchmarkNew-8                 4         322492350 ns/op
PASS
ok      github.com/matryer/moq/internal/registry        8.735s

After:

go test -bench=. ./internal/registry -count 3
goos: linux
goarch: amd64
pkg: github.com/matryer/moq/internal/registry
cpu: Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz
BenchmarkNew-8                15          76012420 ns/op
BenchmarkNew-8                14          76392171 ns/op
BenchmarkNew-8                14          76113471 ns/op
PASS
ok      github.com/matryer/moq/internal/registry        3.520s

The following shows an approximate time improvement to execute all tests on my dev machine:

Before:

go clean -testcache && time go test ./...
?       github.com/matryer/moq  [no test files]
?       github.com/matryer/moq/generate [no test files]
ok      github.com/matryer/moq/example  0.002s [no tests to run]
ok      github.com/matryer/moq/internal/registry        0.002s [no tests to run]
ok      github.com/matryer/moq/internal/template        0.002s
ok      github.com/matryer/moq/pkg/moq  11.691s

real    0m17.944s
user    0m28.584s
sys     0m3.847s

After:

$ go clean -testcache && time go test ./...
?       github.com/matryer/moq  [no test files]
?       github.com/matryer/moq/generate [no test files]
ok      github.com/matryer/moq/example  0.002s [no tests to run]
ok      github.com/matryer/moq/internal/registry        0.002s [no tests to run]
ok      github.com/matryer/moq/internal/template        0.002s
ok      github.com/matryer/moq/pkg/moq  3.704s

real    0m9.468s
user    0m4.982s
sys     0m2.330s

[sudo-suhas]

Thanks for the perf improvement change @samherrmann 🎉

[hypnoglow]

I can confirm that for one of our projects the generation time reduced significantly.

Before:

task gen  131.44s user 31.98s system 611% cpu 26.742 total

After:

task gen  17.54s user 24.17s system 485% cpu 8.582 total

[fsaintjacques]

Is it possible to tag this? We install moq via go.mod, it would be nice if we could pin it to a specific stable version.

[sudo-suhas]

I have added a tag - https://github.com/matryer/moq/releases/tag/v0.3.3. However, there was a problem with goreleaser config and it did not attach the binaries to the release. Will fix the goreleaser config when I can, until then, hope the tag suffices.