connection: add ContextDialer interface and support for custom dialers

[fasmide]

At its core, this adds a NewConnectionWithDialer. The main usecase, at least for me, was to connect to unix sockets on remote machines...

[Foxboron]

I would like to see a small test for this, but the code does not have a lot of test coverage so that might be a high ask.

[fasmide]

I would like to see a small test for this, but the code does not have a lot of test coverage so that might be a high ask.

I think it might be easy enough to just connect to a simple tcp listener without doing any varlink call's ...

[Foxboron]

Cool! LGTM :)

I pinged the other maintainers just in case there are any more input before the merge

[fasmide]

@Foxboron ive added a connection_test.go - it only checks if the socket connects (and if the dialer was used) - does not do any varlink calls

[fasmide]

It should be noted that if we try to test the whole thing, it fails:

$  go test -v ./...
# github.com/varlink/go/cmd/varlink-go-certification
cmd/varlink-go-certification/main.go:145:26: undefined: orgvarlinkcertification.VarlinkInterface
cmd/varlink-go-certification/main.go:194:69: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:198:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:206:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:218:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:230:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:241:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:253:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:288:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:321:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:321:70: too many errors
FAIL	github.com/varlink/go/cmd/varlink-go-certification [build failed]
?   	github.com/varlink/go/cmd/varlink-go-certification/orgvarlinkcertification	[no test files]
....

But i dont know if its releated to these changes - these issues seem to be present in master as well:

 ~  github.com  varlink  128  5ms 628µs  $  git clone git@github.com:varlink/go.git varlink-go
Cloning into 'varlink-go'...
remote: Enumerating objects: 1548, done.
remote: Counting objects: 100% (17/17), done.
remote: Compressing objects: 100% (15/15), done.
remote: Total 1548 (delta 2), reused 2 (delta 2), pack-reused 1531 (from 2)
Receiving objects: 100% (1548/1548), 243.89 KiB | 904.00 KiB/s, done.
Resolving deltas: 100% (930/930), done.
 ~  github.com  varlink  2s 179ms  $  cd varlink-go/
 ~  github.com  varlink  varlink-go  master  3ms 980µs  $  go test -v ./...
# github.com/varlink/go/cmd/varlink-go-certification
cmd/varlink-go-certification/main.go:145:26: undefined: orgvarlinkcertification.VarlinkInterface
cmd/varlink-go-certification/main.go:194:69: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:198:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:206:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:218:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:230:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:241:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:253:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:288:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:321:70: undefined: orgvarlinkcertification.VarlinkCall
cmd/varlink-go-certification/main.go:321:70: too many errors
FAIL	github.com/varlink/go/cmd/varlink-go-certification [build failed]
?   	github.com/varlink/go/cmd/varlink-go-certification/orgvarlinkcertification	[no test files]

[Foxboron]

You need to run go generate on the sources before running the test suite. See the makefile; https://github.com/varlink/go/blob/master/Makefile#L1

[fasmide]

You need to run go generate on the sources before running the test suite. See the makefile; https://github.com/varlink/go/blob/master/Makefile#L1

Nice catch - if running the generate command beforehand, everything passes :)