ramamimu / golang

learning go language

How to Run

Build Production Mode

go build <name_file>

Run Production Mode

./<exe_file>

Development Mode Fast Build and Run

go run <name_file>

Unit Test

• have to use last name _test, for example: hello_world_test.go

• the function firstname is Test.., for Example: TestHelloWorld()

• add the parameter t *testing.T with no return value.

go test <path>
go test -v <path>   // -v use to show the logs
go test -v -run=<name_function> <path> -count=1   // -count to ignore caching

/*
** Either run all tests with go test -v or specify the source files that your test depends on, e.g.
*/
go test double.go double_test.go

Testing.T

• Parameter for unit testing

• Fail() failing the unit test but continue till finish.

• FailNow() failing the unit test and stoppped at the same time.

• Error() call Fail() with print an error as a logging.

• Fatal() call FailNow() with print an error as a logging.

Testing.M

• Parameter for testing in main

Testing.B

• Parameter for brenchmarking

Goroutines

• goroutine is pretty small, it work as concurrency instead of parallel.

channel

• channel is an alternative to receive data by goroutine. it is being a tunnel to communicate with goroutine function. goroutine will be blocked untill the channel receive the data (blocking). The concept is similar with async await in javascript.

channel := make(chan int)
channel <- 19               // to assign the data
bufferData <- channel       // to give the data

• channel only buffer one data. If want more, need another goroutine to create

• please close channel if it's not used due to memory leak.

• by default, the parameter is parsing the value. It is different with channel. If parsing the channel, it is automatically passing the reference.

• channel is possible to give a sign in and out while parsing as parameter. chan<- for in and <-chan for out.

• Buffered Channel use to buffer data whenever didn't available or in some case to handle sender faster than receiver.

channel := make(chan string, 3)   // create channel with 3 buffer long.