🐛 Trailing comma on `*.jsonc` warns with correct rules

[wesleycoder]

VS Code version

1.86.0

Extension version

v2024.3.70509

Biome version

1.7.3

Operating system

• Windows
• macOS
• Linux

Description

When using jsonc as the format for any *.jsonc file with the appropriate rules (below), the linter still warns about trailing commas.

I did try with a bare minimal reproduction repo and the error persists.

Steps to reproduce

• Initialize a minimal reproduction repository (with bun for example):

  mkdir biome-test
  cd biome-test
  bun init .

• add and initialize biome

  bun add --dev --exact @biomejs/biome
  bunx @biomejs/biome init --jsonc

• add the rules for allowing trailing commas to biome.jsonc

  {
  	"$schema": "https://biomejs.dev/schemas/1.7.3/schema.json",
  	"organizeImports": {
  		"enabled": true,
  	},
  	"linter": {
  		"enabled": true,
  		"rules": {
  			"recommended": true,
  		},
  	},
  	"json": {
  		"formatter": {
  			"trailingCommas": "all",
  		},
  		"parser": {
  			"allowTrailingCommas": true,
  		},
  	},
  }

• format the document so it adds the trailing commas

  bunx @biomejs/biome format --write biome.jsonc

• at this point vscode will be warning about trailing commas on the Problems view
• note that running lint via biome won't warn

  bunx @biomejs/biome lint biome.jsonc

[EDIT]

Just tried with a test.jsonc file and the error seems to propagate to other files as well:

• add a test.jsonc file to the repo

  echo '{\n"hello": "world"\n}' > test.jsonc

• format it:

  bunx @biomejs/biome format --write test.jsonc

• same behavior occurs
  

Expected behavior

We should not see any warning for trailing commas on *.jsonc while the rules allow for it.
The same behavior should occur if the overrides section contains an include for a pattern that targets **/*.jsonc.

Does this issue occur when using the CLI directly?

No

Logs

Logs

[Trace - 11:34:57 PM] Sending request 'textDocument/codeAction - (1849)'.
Params: {
    "textDocument": {
        "uri": "file:///Volumes/dev/biome-test/biome.jsonc"
    },
    "range": {
        "start": {
            "line": 13,
            "character": 26
        },
        "end": {
            "line": 13,
            "character": 26
        }
    },
    "context": {
        "diagnostics": [],
        "triggerKind": 2
    }
}
[Trace - 11:34:57 PM] Received response 'textDocument/codeAction - (1849)' in 1ms.

Result: []
[Trace - 11:35:01 PM] Sending request 'textDocument/codeAction - (1850)'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc"

},

"range": {

"start": {

"line": 0,

"character": 0

},

"end": {

"line": 20,

"character": 0

}

},

"context": {

"diagnostics": [],

"only": [

"source.fixAll"

],

"triggerKind": 2

}

}
[Trace - 11:35:01 PM] Received response 'textDocument/codeAction - (1850)' in 3ms.

Result: []
[Trace - 11:35:01 PM] Sending request 'textDocument/codeAction - (1851)'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc"

},

"range": {

"start": {

"line": 0,

"character": 0

},

"end": {

"line": 20,

"character": 0

}

},

"context": {

"diagnostics": [],

"only": [

"source.organizeImports"

],

"triggerKind": 2

}

}
[Trace - 11:35:01 PM] Received response 'textDocument/codeAction - (1851)' in 1ms.

Result: []
[Trace - 11:35:01 PM] Sending request 'textDocument/formatting - (1852)'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc"

},

"options": {

"tabSize": 2,

"insertSpaces": false,

"trimFinalNewlines": true,

"insertFinalNewline": true

}

}
[Trace - 11:35:01 PM] Received response 'textDocument/formatting - (1852)' in 0ms.

Result: [

{

"range": {

"start": {

"line": 0,

"character": 0

},

"end": {

"line": 21,

"character": 0

}

},

"newText": "{\n\t"$schema": "https://biomejs.dev/schemas/1.7.3/schema.json",\n\t"organizeImports": {\n\t\t"enabled": true,\n\t},\n\t"linter": {\n\t\t"enabled": true,\n\t\t"rules": {\n\t\t\t"recommended": true,\n\t\t},\n\t},\n\t"json": {\n\t\t"formatter": {\n\t\t\t"trailingCommas": "all",\n\t\t},\n\t\t"parser": {\n\t\t\t"allowTrailingCommas": true,\n\t\t},\n\t},\n}\n"

}

]
[Trace - 11:35:01 PM] Sending notification 'textDocument/didChange'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc",

"version": 76

},

"contentChanges": [

{

"range": {

"start": {

"line": 18,

"character": 2

},

"end": {

"line": 18,

"character": 2

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 17,

"character": 3

},

"end": {

"line": 17,

"character": 3

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 16,

"character": 30

},

"end": {

"line": 16,

"character": 30

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 13,

"character": 26

},

"end": {

"line": 13,

"character": 26

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 9,

"character": 3

},

"end": {

"line": 9,

"character": 3

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 8,

"character": 22

},

"end": {

"line": 8,

"character": 22

}

},

"rangeLength": 0,

"text": ","

},

{

"range": {

"start": {

"line": 3,

"character": 17

},

"end": {

"line": 3,

"character": 17

}

},

"rangeLength": 0,

"text": ","

}

]

}
[Trace - 11:35:01 PM] Received notification 'textDocument/publishDiagnostics'.

Params: {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc",

"diagnostics": [],

"version": 76

}
[Trace - 11:35:01 PM] Sending notification 'textDocument/didSave'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc"

}

}
[Trace - 11:35:01 PM] Sending request 'textDocument/codeAction - (1853)'.

Params: {

"textDocument": {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc"

},

"range": {

"start": {

"line": 13,

"character": 27

},

"end": {

"line": 13,

"character": 27

}

},

"context": {

"diagnostics": [

{

"range": {

"start": {

"line": 13,

"character": 26

},

"end": {

"line": 13,

"character": 27

}

},

"message": "Trailing comma",

"code": 519,

"severity": 2,

"source": "jsonc"

}

],

"triggerKind": 2

}

}
[Trace - 11:35:01 PM] Received response 'textDocument/codeAction - (1853)' in 1ms.

Result: []
[Trace - 11:35:01 PM] Sending notification 'workspace/didChangeWatchedFiles'.

Params: {

"changes": [

{

"uri": "file:///Volumes/dev/biome-test/biome.jsonc",

"type": 2

}

]

}
[Trace - 11:35:01 PM] Received request 'client/unregisterCapability - (39)'.

Params: {

"unregisterations": [

{

"id": "biome_did_change_extension_settings",

"method": "workspace/didChangeConfiguration"

},

{

"id": "biome_range_formatting",

"method": "textDocument/rangeFormatting"

},

{

"id": "biome_on_type_formatting",

"method": "textDocument/onTypeFormatting"

},

{

"id": "biome_rename",

"method": "textDocument/rename"

},

{

"id": "biome_formatting",

"method": "textDocument/formatting"

},

{

"id": "biome_did_change_workspace_settings",

"method": "workspace/didChangeWatchedFiles"

}

]

}
[Trace - 11:35:01 PM] Sending response 'client/unregisterCapability - (39)'. Processing request took 0ms

No result returned.
[Trace - 11:35:01 PM] Received request 'client/registerCapability - (40)'.

Params: {

"registrations": [

{

"id": "biome_did_change_extension_settings",

"method": "workspace/didChangeConfiguration"

},

{

"id": "biome_range_formatting",

"method": "textDocument/rangeFormatting"

},

{

"id": "biome_on_type_formatting",

"method": "textDocument/onTypeFormatting",

"registerOptions": {

"documentSelector": null,

"firstTriggerCharacter": "}",

"moreTriggerCharacter": [

"]",

")"

]

}

},

{

"id": "biome_rename",

"method": "textDocument/rename"

},

{

"id": "biome_formatting",

"method": "textDocument/formatting"

},

{

"id": "biome_did_change_workspace_settings",

"method": "workspace/didChangeWatchedFiles",

"registerOptions": {

"watchers": [

{

"globPattern": "/Volumes/dev/biome-test/biome.json",

"kind": 7

},

{

"globPattern": "/Volumes/dev/biome-test/biome.jsonc",

"kind": 7

},

{

"globPattern": "/Volumes/dev/biome-test/rome.json",

"kind": 7

}

]

}

}

]

}
[Trace - 11:35:01 PM] Sending response 'client/registerCapability - (40)'. Processing request took 0ms

No result returned.
[Trace - 11:35:01 PM] Received notification 'textDocument/publishDiagnostics'.

Params: {

"uri": "file:///Volumes/dev/biome-test/biome.jsonc",

"diagnostics": [],

"version": 76

}
[Trace - 11:35:01 PM] Received notification 'textDocument/publishDiagnostics'.

Params: {

"uri": "file:///Volumes/dev/biome-test/package.json",

"diagnostics": [],

"version": 2

}

[ematipico]

Those warnings aren't emitted by Biome. They are probably emitted by another language server running in your VSCode, which doesn't support trailing commas. That's probably the built-in language server.

If you hover with your mouse on the diagnostic, it might tell you which language server is emitting the diagnostic.

[wesleycoder]

You are 90% right @ematipico, this was very helpful, thanks.

This must be indeed the vscode built-in json language server.

I could fix the warning for other *.jsonc files by adding this to my vscode settings:

{
  // ...
  "json.schemas": [
    {
      "fileMatch": ["*.jsonc"],
      "schema": {
        "allowTrailingCommas": true,
      },
    },
  ],
}

But this doesn't affect the biome.jsonc, neither with "fileMatch": ["biome.jsonc"].

I'll be researching it more until the weekend and coming back here if I find a solution, if not I'll just deny trailing commas for biome.jsonc in the rules.
For now I'm happy to close the issue as it most certainly is not a fault on this extension.

Thank you so much again, this is now very usable.