x/tools/gopls: CL 200604 does not take into account ContentFormat

[myitcv]

What version of Go are you using (go version)?

$ go version
go version devel +acf3ff2e8a Tue Dec 3 17:35:06 2019 +0000 linux/amd64
$ go list -m golang.org/x/tools
golang.org/x/tools v0.0.0-20191206204035-259af5ff87bd => /home/myitcv/gostuff/src/golang.org/x/tools
$ go list -m golang.org/x/tools/gopls
golang.org/x/tools/gopls v0.1.8-0.20191206204035-259af5ff87bd => /home/myitcv/gostuff/src/golang.org/x/tools/gopls

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/myitcv/.cache/go-build"
GOENV="/home/myitcv/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/myitcv/gostuff"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/myitcv/gos"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/myitcv/gostuff/src/github.com/myitcv/govim/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build041971431=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Starting gopls with Initialize params as follows:

{
	"Workspace": {
		"configuration": true,
		"didChangeConfiguration": {
			"dynamicRegistration": true
		},
		"didChangeWatchedFiles": {},
		"executeCommand": {},
		"symbol": {
			"symbolKind": {}
		},
		"workspaceEdit": {}
	},
	"textDocument": {
		"codeAction": {
			"codeActionLiteralSupport": {
				"codeActionKind": {
					"valueSet": null
				}
			}
		},
		"codeLens": {},
		"colorProvider": {},
		"completion": {
			"completionItem": {
				"tagSupport": {
					"valueSet": null
				}
			},
			"completionItemKind": {}
		},
		"declaration": {},
		"definition": {},
		"documentHighlight": {},
		"documentLink": {},
		"documentSymbol": {
			"symbolKind": {}
		},
		"foldingRange": {},
		"formatting": {},
		"hover": {
			"contentFormat": [
				"plaintext"
			]
		},
		"implementation": {},
		"onTypeFormatting": {},
		"publishDiagnostics": {
			"tagSupport": {
				"valueSet": null
			}
		},
		"rangeFormatting": {},
		"references": {},
		"rename": {},
		"selectionRange": {},
		"signatureHelp": {
			"signatureInformation": {
				"parameterInformation": {}
			}
		},
		"synchronization": {},
		"typeDefinition": {}
	}
}

Note hover content format is plaintext.

Then trigger a hover, and observe the following response:

{
	"kind": "plaintext",
	"value": "func fmt.Println(a ...interface{}) (n int, err error)\nPrintln formats using the default formats for its operands and writes to standard output.\nSpaces are always added between operands and a newline is appended.\nIt returns the number of bytes written and any write error encountered.\n\n[Println on pkg.go.dev](https://pkg.go.dev/fmt#Println)"
}

Note the markdown formatting around the pkg.go.dev link.

What did you expect to see?

No markdown formatting in the plaintext hover response.

What did you see instead?

Markdown formatting.

It's also unclear to me that we want to unconditionally add this line to every hover documentation response.

---

cc @stamblerre @heschik

[stamblerre]

Thanks for reporting this. I've already mailed CL 210201, which should address this.

[gopherbot]

Change https://golang.org/cl/210201 mentions this issue: internal/lsp: improve link in documentation on hover