@flairjs/core

The core transformation engine for Flair, built with Rust for maximum performance.

Overview

This package contains the core logic for transforming JSX files with Flair styles. It uses:

• OXC for fast AST parsing and manipulation
• Lightning CSS for CSS parsing, transformation, and optimization
• NAPI-RS for Node.js bindings

Installation

npm install @flairjs/core

You normally won't have to install this manually, it will be included with the bundler package.

API

transformCode(code, filePath, options, cssPreprocessor?)

Transforms JSX/TSX code containing Flair styles.

Parameters:

• code: string - The source code to transform
• filePath: string - Path to the file being transformed
• options: TransformOptions - Transformation options
• cssPreprocessor?: (css: string) => string - Optional CSS preprocessor function

Returns: TransformOutput | null

TransformOptions

interface TransformOptions {
  cssOutDir: string                 // Output directory for generated CSS
  classNameList?: Array<string>     // List of class names to process
  useTheme?: boolean               // Enable theme processing
  theme?: Theme                    // Theme configuration
  appendTimestampToCssFile?: boolean // Add timestamp to CSS filename
}

TransformOutput

interface TransformOutput {
  code: string              // Transformed JavaScript/TypeScript code
  sourcemap?: string       // Source map (if generated)
  css: string             // Extracted CSS
  logs: Array<LogEntry>   // Build logs and warnings
  generatedCssName?: string // Name of generated CSS file
}

Theme Interface

interface Theme {
  breakpoints: Record<string, string>
  prefix?: string
}

Platform Support

This package includes native binaries for:

• Windows (x64, x86, ARM64)
• macOS (x64, ARM64)
• Linux (x64, ARM64, ARMv7, musl variants)
• FreeBSD (x64)
• Android (ARM64, ARMv7)
• WebAssembly (WASI)

Development

Building from Source

# Install Rust and Node.js dependencies
pnpm install

# Build the native module in debug mode
pnpm run build:debug
# Or prod build
pnpm run build

# Run tests
pnpm test

Architecture

The core is structured as follows:

• src/lib.rs - Main entry point and NAPI bindings
• src/transform.rs - Core transformation logic
• src/parse_css.rs - CSS parsing and processing
• src/style_tag.rs - <Style> tag handling
• src/flair_property.rs - .flair property processing
• src/update_attribute.rs - Class name injection

License

MIT