@markschema/mdshape

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schema.errorMap ​

Type: error-map

Signature: schema.errorMap(...)

What It Is ​

schema.errorMap(...) is used here as a contract-first parser powered by explicit section targeting, typed field extraction, and custom error mapping for schema error map scenarios. With document(), section(), fields(), and number() in the schema, 1 h1 heading, 1 h2 section, and list content is converted into top-level keys meta without manual schema error map post-processing. Error cases report issue codes like invalid_number, making operational diagnostics for schema error map flows consistent across local runs and CI.

When to Use ​

This method is a strong fit for typed markdown parsing with deterministic contracts where deterministic schema error map parsing matters more than free-form flexibility. Do not default to it for exploratory drafts that intentionally avoid strict validation around schema error map; the main cost is key-level strictness that improves typing but rejects ad-hoc variations. For best results, compose schema.errorMap(...) with document(), section(), fields(), and number() so schema error map schema intent stays readable and output remains predictable.

schema.errorMap(...) ​

Input Markdown ​

md
## 1. META

- Score: 7

Schema ​

ts
import { md } from '@markschema/mdshape'

const schema = md
  .document({
    meta: md.section('1. META').fields({
      Score: md.number(),
    }),
  })
  .errorMap((issue) => {
    if (issue.code === 'invalid_number') return 'Schema map: score must be numeric'
    return undefined
  })

const result = schema.safeParse(markdown)

Result ​

Success ​

json
{
  "success": true,
  "data": {
    "meta": {
      "Score": 7
    }
  }
}

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.

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