x/tools/gopls: some properties/defaults from `gopls api-json` are invalid

[hyangah]

$ gopls -v version
Build info
----------
golang.org/x/tools/gopls master
    golang.org/x/tools/gopls@v0.0.0-20201013201025-64a9e34f3752 h1:WOieoYgx8c4Yz9/oW7VgjvzIsjTN0++21yoFC15q+RY=
    github.com/BurntSushi/toml@v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
    github.com/google/go-cmp@v0.5.1 h1:JFrFEBb2xKufg6XkJsJr+WbKb4FQlURi5RUcBveYu9k=
    github.com/sergi/go-diff@v1.1.0 h1:we8PVUC3FE2uYfodKH/nBHMSetSfHDR6scGdBi+erh0=
    golang.org/x/mod@v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
    golang.org/x/sync@v0.0.0-20200625203802-6e8e738ad208 h1:qwRHBd0NqMbJxfbotnDhm2ByMI1Shq4Y6oRJo21SGJA=
    golang.org/x/tools@v0.0.0-20201013201025-64a9e34f3752 h1:2ntEwh02rqo2jSsrYmp4yKHHjh0CbXP3ZtSUetSB+q8=
    golang.org/x/xerrors@v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
    honnef.co/go/tools@v0.0.1-2020.1.5 h1:nI5egYTGJakVyOryqLs1cQO5dO0ksin5XXs2pspk75k=
    mvdan.cc/gofumpt@v0.0.0-20200802201014-ab5a8192947d h1:t8TAw9WgTLghti7RYkpPmqk4JtQ3+wcP5GgZqgWeWLQ=
    mvdan.cc/xurls/v2@v2.2.0 h1:NSZPykBXJFCetGZykLAxaL6SIpvbVy/UFEniIfHAa8A=

But reproducible with the latest stable version of gopls (gopls settings-json).

Configure the vscode gopls section with the default values listed in settings.md@64a9e34

  "gopls": {
    "env": [],
    "semanticTokens": false,
    "experimentalPackageCacheKey": false,
    "completionBudget": 100000000,
    "literalCompletions": true,
  }

See gopls complaining about the default values and triggering multiple notification popups.

[Trace - 23:17:01.044 PM] Sending response 'workspace/configuration - (2)' in 4ms.
Result: [{"env":[],"semanticTokens":false,"experimentalPackageCacheKey":false,"completionBudget":100000000,"literalCompletions":true},null]

[Trace - 23:17:01.044 PM] Received notification 'window/showMessage'.
Params: {"type":1,"message":"invalid config gopls.env type []interface {}"}

[Trace - 23:17:01.044 PM] Received notification 'window/showMessage'.
Params: {"type":1,"message":"unexpected gopls setting \"semanticTokens\""}

[Trace - 23:17:01.044 PM] Received notification 'window/showMessage'.
Params: {"type":1,"message":"unexpected gopls setting \"experimentalPackageCacheKey\""}

[Trace - 23:17:01.044 PM] Received notification 'window/showMessage'.
Params: {"type":1,"message":"Invalid type float64 for string option \"completionBudget\""}

[Trace - 23:17:01.045 PM] Received notification 'window/showMessage'.
Params: {"type":1,"message":"unexpected gopls setting \"literalCompletions\""}

Issues:

• semanticTokens, experimentalPackageCacheKey, literalCompletions were unexpected
• completionBudget is time.Duration type. The default value 100000000 is interpreted as float64. I tried to supply "100000000" (string type) which still fails due to parsing error ( Params: {"type":1,"message":"failed to parse duration \"100000000\": time: missing unit in duration \"100000000\""})
  Note: the error message does not include the property name which needs to be addressed too.
• env section is defined as []string following source.UserOptions.Env
  In VS Code, environment variable collection is often map[string]string type, so string array type is unusual.
  And, gopls doesn't accept default [] but accepts {}.

[gopherbot]

Change https://golang.org/cl/262345 mentions this issue: internal/lsp: fix mismatches between doc and settings

[gopherbot]

Change https://golang.org/cl/262351 mentions this issue: internal/lsp: fix env setting type

[gopherbot]

Change https://golang.org/cl/262353 mentions this issue: internal/lsp/source: include setting name in all settings errors