inline-schema/csv-loader.md

# inline-schema/csv-loader

A rspack loader for CSV files that uses inline-schema for type validation.

## Installation

```bash
npm install inline-schema
```

## Usage

The loader expects:
- **First row**: Property names (headers)
- **Second row**: Inline-schema definitions for each property
- **Remaining rows**: Data values

### Example CSV

```csv
name,age,active,scores
string,number,boolean,number[]
Alice,30,true,[90; 85; 95]
Bob,25,false,[75; 80; 70]
```

### rspack.config.js

```javascript
module.exports = {
  module: {
    rules: [
      {
        test: /\.schema\.csv$/,
        use: {
          loader: 'inline-schema/csv-loader',
          options: {
            delimiter: ',',
            quote: '"',
            escape: '\\',
            bom: true,        // 处理 BOM (默认 true)
            comment: '#',     // 忽略 # 开头的注释行 (默认 '#')
            trim: true,       // 修剪表头和值的前后空格 (默认 true)
            // emitTypes: false, // 禁用类型定义生成 (默认 true)
            // typesOutputDir: 'types', // 类型文件输出目录 (可选)
          },
        },
      },
    ],
  },
};
```

### Generated TypeScript Types

当 `emitTypes: true` 时，loader 会自动生成 `.d.ts` 类型定义文件：

```typescript
// data.schema.d.ts
declare module "./data.schema.csv" {
  export interface data_schema {
    name: string;
    age: number;
    active: boolean;
    scores: number[];
  }

  export type RowType = data_schema;

  const data: data_schema[];
  export default data;
}
```

### Importing in TypeScript

```typescript
import data from './data.schema.csv';

// TypeScript 会自动推断类型:
// data: { name: string; age: number; active: boolean; scores: number[] }[]

// 如果启用了 emitTypes，也可以显式导入类型:
import type { RowType } from './data.schema.csv';
```

## Options

| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `delimiter` | string | `,` | Column delimiter |
| `quote` | string | `"` | Quote character |
| `escape` | string | `\` | Escape character |
| `bom` | boolean | `true` | Handle byte order mark |
| `comment` | string \| `false` | `#` | Comment character (set `false` to disable) |
| `trim` | boolean | `true` | Trim headers and values |
| `emitTypes` | boolean | `true` | Generate TypeScript declaration file (.d.ts) |
| `typesOutputDir` | string | `''` | Output directory for generated type files (relative to output path) |

## Schema Syntax

Uses [inline-schema](https://github.com/your-repo/inline-schema) syntax:

| Type | Schema | Example |
|------|--------|---------|
| String | `string` | `hello` |
| Number | `number` | `42` |
| Boolean | `boolean` | `true` |
| Array | `string[]` or `[string][]` | `[a; b; c]` |
| Tuple | `[string; number]` | `[hello; 42]` |

## License

ISC