go.formatFlags not working with gofmt -s (simplify)

[Graham42]

What version of Go, VS Code & VS Code Go extension are you using?

• Run go version to get version of Go
  • go version go1.14.2 linux/amd64
• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders

  • 1.45.0
    d69a79b73808559a91206d73d7717ff5f798f23c
    x64

• Check your installed extensions to get the version of the VS Code Go extension
  • 0.14.1
• Run go env GOOS GOARCH to get the operating system and processor architecture details

  linux
  amd64

Share the Go related settings you have added/edited

{
  "[go]": {
    "editor.formatOnSave": true
  },
  "go.formatTool": "gofmt",
  "go.formatFlags": ["-s"],
  "go.lintTool": "golangci-lint",
  "go.useLanguageServer": true
}

Describe the bug

Setting "go.formatFlags": ["-s"], doesn't work. My code is formatted on save, but the -s flag is not applied.

type foo struct{}

func Do() {
    x := []foo{
        foo{},
        //^^^ `gofmt -s` should remove the type annotation here
    }
    println(x)
}

Steps to reproduce the behavior:

1. Use the above code snippet and vscode settings.
2. Delete some whitespace.
3. Save the file.

Screenshots or recordings

If applicable, add screenshots or recordings to help explain your problem.

[stamblerre]

Thanks for the report. The language server now does this though a source.FixAll code action, so you will need to add the following to the your "[go]" settings block:

"[go]": {
    "editor.codeActionsOnSave": {
        "source.fixAll": true,
    },
 },

[Graham42]

Thanks! That snippet solves the "on save" use case for me. However, if I use the editor "Format Document" command the -s flag is still not applied.

[stamblerre]

You can run the simplifications manually by opening the Command Palette (Ctrl + Shift + P) and selecting "Source Action". I believe this will be added to the right click menu in the next VS Code release.

[Graham42]

This issue is effectively solved for me with the fixAll action on save, I just wanted to share that finding. If you don't consider it a bug that the formatFlags option doesn't apply to the "Format Document" command then feel free to close this issue :slightly_smiling_face:

[stamblerre]

Ok - thanks! The reason it no longer works as part of formatting is that it's now been split out as a code action, as defined in the LSP specification, which is intentional. Closing as result.