zagane is a static analysis tool which can find bugs in spanner's code. zagane consists of several analyzers.

• unstopiter: it finds iterators which did not stop.

You can get zagane by go get command.

$ go get -u github.com/gcpug/zagane

zagane run with go vet as below when Go is 1.12 and higher.

$ go vet -vetool=$(which zagane) github.com/gcpug/spshovel/...
~/go/src/github.com/gcpug/spshovel/spanner/spanner_service.go:29:29: iterator must be stop

When Go is lower than 1.12, just run zagane command with the package name (import path). But it cannot accept some options such as --tags.

$ zagane github.com/gcpug/spshovel/...
~/go/src/github.com/gcpug/spshovel/spanner/spanner_service.go:29:29: iterator must be stop

unstopiter finds spanner.RowIterator which is not calling Stop method or Do method such as below code.

_, _ = client.Single().Query(ctx, stmt).Next()

Analyzers ignore nodes which are annotated by staticcheck's style comments as belows. A ignore comment includes analyzer names and reason of ignoring checking. If you specify zagane as analyzer name, all analyzers ignore corresponding code.

//lint:ignore zagane reason
var n int

//lint:ignore unstopiter reason
_, _ = client.Single().Query(ctx, stmt).Next()

You can get analyzers of zagane from zagane.Analyzers. And you can use them with unitchecker.