Some test failed

[enzo-yang]

go test shows errors sometimes, It's not always happen

there maybe errors like bellow

➜  go-grpc-prometheus git:(master) go test
--- FAIL: TestStreamingIncrementsHandled (0.00s)
        Error Trace:    server_test.go:218
        Error:          Not equal:
                        expected: 1
                        received: 0
        Messages:       grpc_server_handled_total should be incremented for PingList FailedPrecondition

--- FAIL: TestStreamingIncrementsStarted (0.00s)
        Error Trace:    server_test.go:168
        Error:          Not equal:
                        expected: 6
                        received: 5
        Messages:       grpc_server_started_total should be incremented for PingList

--- FAIL: TestServerInterceptorSuite (0.05s)
        server_test.go:86: stopped grpc.Server at: 127.0.0.1:51448
FAIL
exit status 1

[bwplotka]

Yup - it seems flaky. I think because all these tests are based on time (e.g that test case have 1 minute to complete), and Travis being super slow at certain moments.

Any PR fixing that are welcome (:

[knweiss]

FWIW: I'm working on some other fixes and also just noticed occasional test failures in TestServerInterceptorSuite on my local system (8-core, otherwise idle):

$ go test -run=TestServerInterceptorSuite
--- FAIL: TestServerInterceptorSuite (0.11s)
    --- FAIL: TestServerInterceptorSuite/TestStreamingIncrementsHandled (0.01s)
    	server_test.go:218: 
    			Error Trace:	server_test.go:218
    			Error:      	Not equal: 
    			            	expected: 1
    			            	actual  : 0
    			Test:       	TestServerInterceptorSuite/TestStreamingIncrementsHandled
    			Messages:   	grpc_server_handled_total should be incremented for PingList FailedPrecondition
    --- FAIL: TestServerInterceptorSuite/TestStreamingIncrementsStarted (0.00s)
    	server_test.go:168: 
    			Error Trace:	server_test.go:168
    			Error:      	Not equal: 
    			            	expected: 6
    			            	actual  : 5
    			Test:       	TestServerInterceptorSuite/TestStreamingIncrementsStarted
    			Messages:   	grpc_server_started_total should be incremented for PingList
	server_test.go:86: stopped grpc.Server at: 127.0.0.1:50543
FAIL
exit status 1
FAIL	github.com/grpc-ecosystem/go-grpc-prometheus	0.131s

$ go test -run=TestServerInterceptorSuite
--- FAIL: TestServerInterceptorSuite (0.11s)
    --- FAIL: TestServerInterceptorSuite/TestStreamingIncrementsHistograms (0.01s)
    	server_test.go:193: 
    			Error Trace:	server_test.go:193
    			Error:      	Not equal: 
    			            	expected: 4
    			            	actual  : 3
    			Test:       	TestServerInterceptorSuite/TestStreamingIncrementsHistograms
    			Messages:   	grpc_server_handling_seconds_count should be incremented for PingList FailedPrecondition
	server_test.go:86: stopped grpc.Server at: 127.0.0.1:50527
FAIL
exit status 1
FAIL	github.com/grpc-ecosystem/go-grpc-prometheus	0.132s

$ go version
go version go1.10.1 darwin/amd64
$ git describe --tag
v1.1-39-g67e2f48