Go - interface conversion [recovered] - error

Question

The test logs show the following error

row 0 - got data of type graph.Node but wanted graph.Node
--- FAIL: TestAlls (0.84s)
panic: interface conversion: interface {} is graph.Node, not graph.Node [recovered]
    panic: interface conversion: interface {} is graph.Node, not graph.Node

From the following code

nnn = graph.Node{}
nnn, ok = row[0].(graph.Node)
if !ok {
  log.Printf("row 0 - got data of type %T but wanted graph.Node", nnn)
}
neo4jNode := row[0].(graph.Node)

• Is it possible that there are two different types with the same name? (graph.Node)
• In which case, which folders should I clear out?
• What does [recovered] mean?

I am using glide install, go clean, go build, go test.

Answer 1

Is it possible that there are two different types with the same name? (graph.Node)

Yes. If the code that produces the object (whatever is generating rows ) references a different copy of the same library , the types will not match - for example, if you reference library foo , which has graph vendored, it will be referencing its vendored version, while you are referencing your own version. It's also possible to have two completely different packages (different import paths) both named graph but I'm assuming you've ruled this out.

In which case, which folders should I clear out?

It's unfortunately not that simple - you need to look carefully at your dependencies. If you're importing a project as a library, and it has its own dependencies vendored, you're going to have a bad time. That's exactly why it's a bad practice to vendor dependencies in a library (dependencies should only be vendored for binaries).

What does [recovered] mean?

It means a panic was recovered . This is done by the testing library to return accurate test results in the event of a test causing a panic.

Answer 2

The origin of the problem was multiple glide.yaml (& vendor/) in the repository. The solution was to only have a root glide.yaml (& vendor/).