fields

Type: section

Signature: section().fields(shape, options?)

What It Is

section().fields(shape, options?) is used here as a contract-first parser powered by document-level structure checks, explicit section targeting, and typed field extraction for fields scenarios. With document(), section(), fields(), and string() in the schema, 1 h1 heading, 1 h2 section, and list content is converted into top-level keys owner without manual fields post-processing. Error cases report issue codes like missing_section, making operational diagnostics for fields flows consistent across local runs and CI.

When to Use

This method is a strong fit for section-scoped extraction where headings anchor each data slice where deterministic fields parsing matters more than free-form flexibility. Do not default to it for free-form notes with unstable section names around fields; the main cost is key-level strictness that improves typing but rejects ad-hoc variations. For best results, compose section().fields(shape, options?) with document(), section(), fields(), and string() so fields schema intent stays readable and output remains predictable.

section().fields(shape, options?)

Input Markdown

## 1. OWNER

- Name: Alex Turner
- Email: alex@zayra.com

Schema

import { md } from '@markschema/mdshape'

const schema = md.document({
  owner: md.section('1. OWNER').fields({
    Name: md.string().min(3),
    Email: md.email(),
  }),
})

Result

Success

{
  "success": true,
  "data": {
    "owner": {
      "Name": "Alex Turner",
      "Email": "alex@zayra.com"
    }
  }
}

Error

Failure trigger: The input violates one or more constraints declared in the schema; use issues[].path and issues[].code to locate the exact failing node.

{
  "success": false,
  "error": {
    "issues": [
      {
        "code": "missing_section",
        "message": "Missing section \"1. OWNER\"",
        "path": [
          "owner"
        ],
        "line": 1,
        "position": {
          "start": {
            "line": 1,
            "column": 1
          }
        }
      }
    ]
  }
}

Case Sensitivity

fields is case-insensitive by default.

• Markdown key Service matches schema key service
• Markdown key SERVICE also matches schema key service

If you need strict matching, pass { caseInsensitive: false }:

const schema = md.document({
  owner: md.section('1. OWNER').fields(
    {
      service: md.string(),
    },
    { caseInsensitive: false },
  ),
})

See also: caseInsensitive