xxx.go
xxx_test.go
TestXXX(t *testing.T)
BenchmarkXXX(t *testing.B)
xxx_integration_test.go
TestXXX(t *testing.T)
testdata/
xxx.txt
xxy.csv
go test
go test -v
go test ./...
go test -run=TestRotate
go test -benchmem -bench=.
go test -cover
go test ./... -coverprofile=coverage.out
go tool cover -func=coverage.out
go tool cover -html=coverage.out
xxx_integration_test.go
// +build integration
go test -tags=integration
httptest.ResponseRecorder
httptest.Server
https://github.com/golang/mock
https://blog.golang.org/cover