Thank you Gregor. As this is just to make unit test work, if I add
waitgroup in the code, will this affect the real streaming logic?
Is that OK, I check if is it a mock function functionB called, then I tell
it to sleep for a sec before return.
On Thursday, September 10, 2020 at 5:42:21 PM UTC+10 be...@pferdewetten.de
wrote:
> Right, I wanted to write something about the goroutine and forgot about
> it. Sorry about that.
>
> The problem here could be that in the code you posted there's nothing
> waiting on any result from the goroutine, and if the test exits quickly
> enough, it might not get scheduled.
>
> In general, whenever a goroutine is created, you should have some idea
> of when and how it gets to run and when it stops running, and how other
> goroutines wait for it to do its job.
>
> You could do this for example by controlling the lifetime of the
> goroutine with a sync.WaitGroup. Pass in a WaitGroup and call Done() on
> it when the goroutine returns (probably as a deferred call), then call
> Wait() in some other goroutine (for example in your main function or in
> the TestFoo function) so there's some sort of ordering enforced.
>
> In general, you'll need some way of signalling "I'm done copying stuff
> from zipReader to zipWriter" in the goroutine, and you'll need to
> arrange for some other, longer lived, goroutine to wait for that signal.
>
>
> On 10.09.20 09:34, Yvonne Zhang wrote:
> > Thank you Gregor for your quick reply!
> >
> > Anything special I need to think about this go routine logic in my unit
> > test. It might be still running after test returns..?
> >
> > On Thursday, September 10, 2020 at 5:26:13 PM UTC+10
> > be...@pferdewetten.de wrote:
> >
> > If I were you, I'd pass in an interface value to functionA with the
> > signature
> >
> > type Ber interface{
> > functionB(io.Reader, io.Writer)
> > }
> >
> > (assuming that zipReader is an io.Reader, zipWriter is an io.Writer,
> > you
> > may have to adjust this a bit).
> >
> > Then make your mock functionB a method on a type that implements the
> > Ber
> > interface, the same for the real functionB. In unit tests, pass in an
> > instance of the type with the mock method, in real life, pass in an
> > instance of the type with the real method.
> >
> > Note that the types could be as simple as
> >
> > type mockB struct{}
> > func (m mockB) functionB(...)
> >
> > On 10.09.20 09:15, Yvonne Zhang wrote:
> > > Hi,
> > > I have a function streaming a zipreader to browser. It is like this.
> > > func functionA(....)(body io.ReadCloser, err error){
> > >
> > > // some logic to get a zipreader
> > >
> > > body, pipeWriter := io.Pipe()
> > > zipWriter := zip.NewWriter(pipeWriter)
> > >
> > > go func(){
> > > // err := functionB(zipReader, zipWriter)call another
> > function to
> > > prepare files and write to zipwriter
> > > If err != nil{
> > > zipWriter.Close()
> > > _ = pipeWriter.CloseWithError(err)
> > > return
> > > }
> > > zipWriter.Close()
> > > pipeWriter.Close()
> > > }()
> > > return
> > > }
> > >
> > > My question is about unit test about this functionA. I have mock for
> > > functionB. How do I write unit test for functionA with the mock
> > > functionB. It seems my unit test does not work well when it goes
> > into
> > > the goroutine.
> > > Many thanks!
> > >
> > > --
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> >
> https://groups.google.com/d/msgid/golang-nuts/4ca0817a-f1f7-44a9-be3d-3584bcb61b8an%40googlegroups.com
> >
> > >
> > <
> https://groups.google.com/d/msgid/golang-nuts/4ca0817a-f1f7-44a9-be3d-3584bcb61b8an%40googlegroups.com?utm_medium=email&utm_source=footer
> >.
> >
> >
> > --
> > Gregor Best
> > be...@pferdewetten.de
> >
> > --
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>
> > <
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> >.
>
> --
> Gregor Best
> be...@pferdewetten.de
>
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