micro-csv-rfc4180

Minimal RFC 4180 CSV parser and serializer. Zero dependencies.

Three functions. ~70 lines. Works in any Node.js ≥ 18 environment.

Install

npm install micro-csv-rfc4180

Usage

import { csvSplitLine, csvSerializeLine, csvEscapeField } from 'micro-csv-rfc4180';

// Parse a CSV line into fields
csvSplitLine('Alice,"New York, NY",42')
// → ['Alice', 'New York, NY', '42']

// Serialize fields into a CSV line (auto-quotes when needed)
csvSerializeLine(['Alice', 'New York, NY', '42'])
// → 'Alice,"New York, NY",42'

// Escape a single field
csvEscapeField('say "hi"')
// → '"say ""hi"""'

API

csvSplitLine(line: string): string[]

Parse a single CSV line into an array of field values, respecting RFC 4180 quoting rules:

• Fields containing commas, double-quotes, or newlines must be wrapped in double-quotes
• Embedded double-quotes are escaped by doubling them ("")
• Does not handle multi-line quoted fields (newlines inside quotes split across multiple csvSplitLine calls)

csvSerializeLine(fields: string[]): string

Serialize an array of field values into a properly-escaped CSV line.

Fields that contain ,, ", \r, or \n are automatically wrapped in double-quotes with embedded quotes doubled.

csvEscapeField(value: string): string

Escape a single CSV field value. Returns the value unchanged if no escaping is needed.

RFC 4180 compliance

Handles:

• ✓ Quoted fields with embedded commas
• ✓ Quoted fields with embedded double-quotes (doubled)
• ✓ Quoted fields with embedded newlines (\n, \r)
• ✓ Empty fields
• ✓ Trailing commas (produce an empty last field)

Does not handle:

• Multi-line records across csvSplitLine calls (newlines inside quoted fields that span lines)
• BOM markers
• Custom delimiters

License

MIT