XML Formatter makes unreadable documents

[adamsoutar]

Summary

The 'Format Document' option in XML files produces very unusual, near-unreadable XML documents.

Description

Given this XML document:

<WatchFace width="450" height="450" shape="CIRCLE" schemeVersion="1.0.0"><Metadata key="CLOCK_TYPE" value="ANALOG"/><Metadata key="TICK_PER_SECOND" value="15"/><Scene backgroundColor="#ff000000"><ComplicationSlot slotId="0" displayName="Small Box Complication" screenReaderText="" isCustomizable="TRUE" supportedTypes="SMALL_IMAGE " x="180" y="179" width="92" height="92" pivotX="0.5" pivotY="0.5" name="Small Box Complication_0" alpha="255"><DefaultProviderPolicy defaultSystemProvider="EMPTY" defaultSystemProviderType="SMALL_IMAGE"/><BoundingBox x="0" y="0" width="92" height="92" pivotX="0" pivotY="0"/><Complication type="SMALL_IMAGE"><PartImage x="14" y="13" width="69" height="69" pivotX="0.5" pivotY="0.5" name="Image_fd89" alpha="255"><Image resource="[COMPLICATION.SMALL_IMAGE]"/></PartImage></Complication></ComplicationSlot></Scene></WatchFace>

VS Code does this:

Zed does this:

Steps to reproduce:

1. Paste XML into Zed or open an XML document
2. Open the Command Palette and type 'Format Document'
3. Press Enter

Expected Behavior:

<Outer><Inner prop="value"><Innermost /></Inner></Outer>

Is formatted like this:

<Outer>
  <Inner prop="value">
    <Innermost />
  </Inner>
</Outer>

Actual Behavior:

Zed seems to place opening tags in line with the closing brackets of the previous element, and likes to close as many tags on one line as it can. Additionally, the indentation algorithm appears to be unbalanced as the longer the document is, the more everything drifts to the right without going back left.

Zed Settings JSON

{
  "project_panel": {
    "auto_fold_dirs": false
  },
  "ssh_connections": [
    // Redacted.
  ],
  "use_autoclose": false,
  "use_auto_surround": false,
  "indent_guides": {
    "enabled": false
  },
  "features": {
    "edit_prediction_provider": "none",
    "copilot": false
  },
  "vim_mode": false,
  "theme": "Catppuccin Frappé - No Italics",
  "base_keymap": "Atom",
  "telemetry": {
    "diagnostics": false,
    "metrics": false
  },
  "ui_font_size": 15,
  "buffer_font_size": 15,
  "buffer_font_family": "Menlo",
  "tabs": {
    "close_position": "left"
  },
  "git": {
    "inline_blame": {
      "enabled": false
    }
  },
  "tab_bar": {
    "show": true,
    "show_nav_history_buttons": false
  },
  "unstable.ui_density": "compact",
  "toolbar": {
    "breadcrumbs": false,
    "quick_actions": false
  },
  "lsp": {
    "rust-analyzer": {
      "cargo": {
        "buildScripts": {
          "enable": true
        }
      },
      "initialization_options": {
        "check": {
          "command": "clippy"
        },
        "rustfmt": {
          "extraArgs": ["+nightly"]
        }
      }
    }
  },
  "diagnostics": {
    "include_warnings": true,
    "inline": {
      "enabled": true,
      "update_debounce_ms": 150,
      "padding": 4,
      "min_column": 0,
      "max_severity": null
    }
  }
}

Zed Version and System Specs

Zed: v0.192.1 (Zed Preview)
OS: macOS 15.6.0
Memory: 16 GiB
Architecture: aarch64

[notpeter]

XML is not a core Zed feature, it is provided by community extension: sweetppro/zed-xml, but by default it will use prettier/plugin-xml as a formatter.

Similarly, the VSCode formatting is not provided by vscode but via an extension like redhat-developer/vscode-xml. That extension bundles the eclipse/lemminx language server which provides an alternate (and likely superior) formatter.

You can control some of the aspects of prettier via .prettierc.json.

Alternatively I took a stab at getting lemminx LSP working here and got its formatter working (albeit I haven't yet figured out how to configure maxLineWidth and other tunables).

• WIP: Support for lemminx LSP sweetppro/zed-xml#20

If you'd be willing to install my branch as a dev extension you could give it a whirl.

Otherwise this discussion should probably move to the xml extension issues:

• https://github.com/sweetppro/zed-xml/issues/