Rust Crate

Using mdx-formatter-core as a Rust library

Rust Crate

The core formatting engine is available as a standalone Rust crate (mdx-formatter-core) for direct integration in Rust applications. It has no Node.js dependency and can be embedded in CLI tools, desktop apps (Tauri), or any Rust project.

Cargo Dependency

Since the crate is not yet published to crates.io, use one of these dependency forms:

[dependencies]
# Option 1: git dependency (Cargo finds the workspace member by crate name)
mdx-formatter-core = { git = "https://github.com/Takazudo/mdx-formatter" }

# Option 2: local path (for development)
mdx-formatter-core = { path = "../mdx-formatter/crates/mdx-formatter-core" }

Basic Usage

use mdx_formatter_core::{format, FormatterSettings};

let content = "# Hello\nSome text";
let settings = FormatterSettings::default();
let formatted = format(content, &settings);
// formatted == "# Hello\n\nSome text"

The format function runs a convergence loop (up to 3 iterations) to ensure idempotent output. It returns the formatted string directly — no Result wrapping, no async.

FormatterSettings

FormatterSettings mirrors the TypeScript settings structure. Each formatting rule is a separate field:

use mdx_formatter_core::FormatterSettings;

let mut settings = FormatterSettings::default();

// Disable the spacing rule
settings.add_empty_line_between_elements.enabled = false;

let formatted = mdx_formatter_core::format(content, &settings);

Available Settings Fields

Field	Type	Default	Description
`add_empty_line_between_elements`	`AddEmptyLineBetweenElementsSetting`	enabled	Add empty lines between elements
`format_multi_line_jsx`	`FormatMultiLineJsxSetting`	enabled	Format multi-line JSX
`format_html_blocks_in_mdx`	`FormatHtmlBlocksInMdxSetting`	enabled	Format HTML blocks
`expand_single_line_jsx`	`ExpandSingleLineJsxSetting`	disabled	Expand single-line JSX
`indent_jsx_content`	`IndentJsxContentSetting`	disabled	Indent JSX content
`add_empty_lines_in_block_jsx`	`AddEmptyLinesInBlockJsxSetting`	enabled	Empty lines in block JSX
`format_yaml_frontmatter`	`FormatYamlFrontmatterSetting`	enabled	Format YAML frontmatter
`preserve_admonitions`	`PreserveAdmonitionsSetting`	enabled	Preserve Docusaurus admonitions
`error_handling`	`ErrorHandlingSetting`	off	Throw on parse errors
`auto_detect_indent`	`AutoDetectIndentSetting`	disabled	Auto-detect indentation

Loading from JSON

Settings can be created from a partial JSON value, merging with defaults:

use mdx_formatter_core::FormatterSettings;

let json: serde_json::Value = serde_json::json!({
    "addEmptyLineBetweenElements": { "enabled": false },
    "formatMultiLineJsx": { "indentSize": 4 }
});
let settings = FormatterSettings::from_partial_json(&json);

JSON field names use camelCase (matching the TypeScript/config file convention), while Rust struct fields use snake_case.

All 10 settings fields are supported via serde deserialization with camelCase JSON keys.

Public Exports

The crate re-exports through lib.rs:

Symbol	Module	Description
`format`	`formatter`	The main formatting function (panics on error if `throw_on_error` is true)
`try_format`	`formatter`	Returns `Result<String, String>` instead of panicking
`FormatterSettings`	`types`	Settings struct
`format_html_block`	`html_formatter`	HTML block indentation formatter
`load_config`	`config`	Load and merge config from file
`load_full_config`	`config`	Load config + exclude patterns
`load_full_config_from`	`config`	Load config from a specific directory
`load_exclude_patterns`	`config`	Load only exclude patterns
`FullConfig`	`config`	Settings + exclude patterns struct

All symbols are re-exported at the crate root, so use mdx_formatter_core::{format, FormatterSettings} works directly. The parser, types, and html_formatter modules are also public for consumers who need lower-level access.

Status

The Rust crate implements all formatting rules from the TypeScript version. See Rust Rewrite for the full status and remaining infrastructure work.