inline-schema/csv-loader.md

# inline-schema/csv-loader

A rspack/rollup 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/webpack

### 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)
            // writeToDisk: true, // 在 dev server 下写入磁盘 (默认 false)
          },
        },
      },
    ],
  },
};
```

## Vite

### vite.config.ts

```typescript
import { defineConfig } from 'vite';
import { csvLoader } from 'inline-schema/csv-loader/rollup';

export default defineConfig({
  plugins: [
    csvLoader({
      delimiter: ',',
      quote: '"',
      escape: '\\',
      bom: true,
      comment: '#',
      trim: true,
      // emitTypes: false,
      // typesOutputDir: 'types',
      // writeToDisk: true,
    }),
  ],
});
```

## Tsup

### tsup.config.ts

```typescript
import { defineConfig } from 'tsup';
import { csvLoader } from 'inline-schema/csv-loader/rollup';

export default defineConfig({
  entry: ['src/index.ts'],
  format: ['cjs', 'esm'],
  dts: true,
  plugins: [csvLoader()],
});
```

### Generated TypeScript Types

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

```typescript
// data.csv.d.ts
type Table = {
  name: string;
  age: number;
  active: boolean;
  scores: number[];
}[];

declare const data: Table;
export default data;
```

### Importing in TypeScript

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

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

## 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) |
| `writeToDisk` | boolean | `false` | Write .d.ts files directly to disk (useful for dev server) |
| `include` | RegExp \| string \| Array | `/\.csv$/` | Include pattern for CSV files (Rollup only) |
| `exclude` | RegExp \| string \| Array | - | Exclude pattern for CSV files (Rollup only) |

## 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