GO LIST JSON? WHY NOT!?

[DarthHater]

This PR handles:

go list -m all and go list -json -m all commands piped in to Nancy

I went with this approach as the Go Mod list command stuff is all internal. I've copied the struct for Module however, and trimmed it down for now to the fields we likely will ever need.

The approach I took was to:

• Read the stdIn into a []byte, as I don't anticipate it being TOO big (I tried at first to do this by buffering it, but the code was getting extremely complicated for something that should never be like, massive in memory footprint)
• Attempt to read from the []byte as json. If it errors, break the loop, if it doesn't, return everything, GREAT!
• If it exits the loop due to an error (not EOF), I attempt to read it as if it was just a regular list like what we had before
• The function that reads the parsed JSON can handle mods that were replaced now, giving us the accurate version being used

This new method GoParseAgnostic takes an io.Reader as well, so that we can test it a bit easier.

This pull request makes the following changes:

• Switches main.go to use GoListAgnostic
• Implements func GoListAgnostic(stdIn io.Reader) (deps types.ProjectList, err error)
• Implements a private function to parse a GoListModule struct, which has a signature of func modToProjectList(mod types.GoListModule) (dep types.Projects, err error)

It relates to the following issue #s:

• Fixes Handle replace (old version to other version) #142

cc @bhamail / @DarthHater

[MichelKazi]

LGTM!
Just a question though, does this mean parse.GoList is no more?

[DarthHater]

@MichelKazi yep! We would remove that (or rename the other to GoList) when we do a 1.0.0 release

[zendern]

Since #142 called this out as an issue i think we should add a test around it to make sure it is working as expected.

[DarthHater]

I have one! https://github.com/sonatype-nexus-community/nancy/pull/150/files#diff-7b16ed199b45ba365ab40918a65bbb2bR64-R78

[zendern]

My bad i should have been more clear :) that just handles replace for go list and not go list -json. We should probably have a replace test for the json path too.

{
        "Path": "github.com/gorilla/websocket",
        "Version": "v1.4.0",
        "Replace": {
                "Path": "github.com/gorilla/websocket",
                "Version": "v1.4.2",
                "Time": "2020-03-19T17:50:51Z",
                "GoMod": "/Users/ME/go/pkg/mod/cache/download/github.com/gorilla/websocket/@v/v1.4.2.mod"
        },
        "Update": {
                "Path": "github.com/gorilla/websocket",
                "Version": "v1.4.2",
                "Time": "2020-03-19T17:50:51Z"
        },
        "Indirect": true,
        "GoMod": "/Users/ME/go/pkg/mod/cache/download/github.com/gorilla/websocket/@v/v1.4.2.mod"
}

One of those testdata files but with that and maybe another in it.

[DarthHater]

In: 64079e0

[zendern]

Code looks good to me....probably need to update the README too. And add something to the extent that you will get better results if you use go list -m -json

[DarthHater]

@zendern , README updated!