x/tools/gopls: add directness to gopls's CommandAddDependency

[stamblerre]

Repro case:

-- mod/go.mod --
module mod.com

go 1.14

require github.com/esimov/caire v1.0.1
-- mod/main.go --
package main

import (
	"github.com/esimov/caire"
)

func _() {
	caire.RemoveTempImage()
}

Running go mod tidy results in:

module mod.com

go 1.14

require (
	github.com/esimov/caire v1.0.1
	github.com/pkg/errors v0.9.1 // indirect
	golang.org/x/image v0.0.0-20200430140353-33d19683fad8 // indirect
)

[stamblerre]

The extra dependencies are now suggested, but they are not labeled as // indirect. We should modify the diagnostic message to contain the word indirect and add the // indirect automatically.

[heschik]

We have a test case in https://github.com/golang/tools/blob/4fc0492b8eca8657dd80eff56bf885b7258ddd73/gopls/internal/regtest/modfile_test.go#L402 that verifies that dependencies like this are added without an // indirect comment. The test was confusing enough that I didn't try to figure out whether it was correct. It seems wrong to me too, though, and if you agree I'll try to clean up that test and fix it.

[stamblerre]

Yeah, it looks like the comment on the test doesn't actually match what the test checks for.

[heschik]

I added the comment recently because I didn't understand what was going on. I will change the behavior to match my expectations.

[gopherbot]

Change https://golang.org/cl/267578 mentions this issue: internal/lsp: set correct directness when adding new requires