📝 json files with trailing commas aren't formatted

[juliusmarminge]

Environment information

CLI:
  Version:                      1.1.2
  Color support:                true

Platform:
  CPU Architecture:             x86_64
  OS:                           linux

Environment:
  BIOME_LOG_DIR:                unset
  NO_COLOR:                     unset
  TERM:                         "xterm-256color"
  JS_RUNTIME_VERSION:           "v20.11.0"
  JS_RUNTIME_NAME:              "node"
  NODE_PACKAGE_MANAGER:         "npm/10.2.4"

Biome Configuration:
  Status:                       Loaded successfully
  Formatter disabled:           false
  Linter disabled:              false
  Organize imports disabled:    false
  VCS disabled:                 true

Workspace:
  Open Documents:               0

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Configuration

{
    "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
    "formatter": {
        "enabled": true,
        "formatWithErrors": true
    }
}

Additional info

Similar to #1659 but jsonc files are allowed to have trailing commas so it's still a different issue I think. Maybe this even falls under the category of non-goals, but it's a very nice-to-have feature when editing JSON files.

Playground link

https://codesandbox.io/p/devbox/gallant-black-skhrkn?layout=%257B%2522sidebarPanel%2522%253A%2522EXPLORER%2522%252C%2522rootPanelGroup%2522%253A%257B%2522direction%2522%253A%2522horizontal%2522%252C%2522contentType%2522%253A%2522UNKNOWN%2522%252C%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522id%2522%253A%2522ROOT_LAYOUT%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522UNKNOWN%2522%252C%2522direction%2522%253A%2522vertical%2522%252C%2522id%2522%253A%2522clrt0gimx00053b6erpr5mq4g%2522%252C%2522sizes%2522%253A%255B47.880897138437746%252C52.119102861562254%255D%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522EDITOR%2522%252C%2522direction%2522%253A%2522horizontal%2522%252C%2522id%2522%253A%2522EDITOR%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522EDITOR%2522%252C%2522id%2522%253A%2522clrt0gimx00023b6eaofkd6ee%2522%257D%255D%257D%252C%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522SHELLS%2522%252C%2522direction%2522%253A%2522horizontal%2522%252C%2522id%2522%253A%2522SHELLS%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522SHELLS%2522%252C%2522id%2522%253A%2522clrt0gimx00033b6e8e78mfxc%2522%257D%255D%252C%2522sizes%2522%253A%255B100%255D%257D%255D%257D%252C%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522DEVTOOLS%2522%252C%2522direction%2522%253A%2522vertical%2522%252C%2522id%2522%253A%2522DEVTOOLS%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522DEVTOOLS%2522%252C%2522id%2522%253A%2522clrt0gimx00043b6ego92wpb3%2522%257D%255D%252C%2522sizes%2522%253A%255B100%255D%257D%255D%252C%2522sizes%2522%253A%255B86.2709277212127%252C13.7290722787873%255D%257D%252C%2522tabbedPanels%2522%253A%257B%2522clrt0gimx00023b6eaofkd6ee%2522%253A%257B%2522id%2522%253A%2522clrt0gimx00023b6eaofkd6ee%2522%252C%2522tabs%2522%253A%255B%257B%2522id%2522%253A%2522clrt0gimw00013b6ewh0j3lid%2522%252C%2522mode%2522%253A%2522permanent%2522%252C%2522type%2522%253A%2522FILE%2522%252C%2522filepath%2522%253A%2522%252F.codesandbox%252FDockerfile%2522%252C%2522state%2522%253A%2522IDLE%2522%257D%255D%252C%2522activeTabId%2522%253A%2522clrt0gimw00013b6ewh0j3lid%2522%257D%252C%2522clrt0gimx00043b6ego92wpb3%2522%253A%257B%2522tabs%2522%253A%255B%255D%252C%2522id%2522%253A%2522clrt0gimx00043b6ego92wpb3%2522%257D%252C%2522clrt0gimx00033b6e8e78mfxc%2522%253A%257B%2522id%2522%253A%2522clrt0gimx00033b6e8e78mfxc%2522%252C%2522activeTabId%2522%253A%2522clrt0hsbh00ac3b6eu7p0eb8y%2522%252C%2522tabs%2522%253A%255B%257B%2522id%2522%253A%2522clrt0hsbh00ac3b6eu7p0eb8y%2522%252C%2522mode%2522%253A%2522permanent%2522%252C%2522type%2522%253A%2522TERMINAL%2522%252C%2522shellId%2522%253A%2522clrt0hsgq001hefipejt2az06%2522%257D%255D%257D%257D%252C%2522showDevtools%2522%253Atrue%252C%2522showShells%2522%253Atrue%252C%2522showSidebar%2522%253Atrue%252C%2522sidebarPanelSize%2522%253A15%257D

Code of Conduct

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[ematipico]

Have you tried to enable the trailing comma option?

https://biomejs.dev/reference/configuration/#jsonparserallowtrailingcommas

[juliusmarminge]

Just tried and doesn't seem to help:

[Sec-ant]

If I understand correctly, Biome doesn't have a language setting block for jsonc, so the correct way to parse/format a .jsonc file is by setting json.parser.allowTrailingCommas and json.parser.allowComments these two options, whether in a overrides block or globally. So that makes this issue and #1659 the same IMO.

And despite that sameness, I think another thing that @juliusmarminge wants to ask here is that whether Biome will consider supporting formatting invalid syntaxes (like trailing commas) in a standard json file when it is being edited, in which case formatting on the fly can give better dev experience?

[ematipico]

And despite that sameness, I think another thing that @juliusmarminge wants to ask here is that whether Biome will consider supporting formatting invalid syntaxes (like trailing commas) in a standard json file when it is being edited, in which case formatting on the fly can give better dev experience?

This is already possible nowadays by using formatter.formatWithErrors. With overrides, you can decide to enable this behaviour only to .jsonc files.

{
	"overrides": [
		{
			"include": ["*.jsonc"],
				"formatter": {
					"formatWithErrors": true
				}
		}
	]
}

[Sec-ant]

This is already possible nowadays by using formatter.formatWithErrors. With overrides, you can decide to enable this behaviour only to .jsonc files.

I wasn't aware of the formatWithErrors option when I left that comment, thanks for the clarification.