Registry / serialization / remark-lint-frontmatter-schema

remark-lint-frontmatter-schema

library3.15.4jsnpmunverified

Validate Markdown frontmatter YAML against an associated JSON schema using remark-lint. Current version: 3.15.4 (released Oct 2023). Released regularly with bug fixes. Key differentiators: supports JSON Schema draft-07, both in-file $schema and global pattern associations, auto-fixes, integration with VS Code and ESLint MDX, and CLI reporting. Uses ajv for validation.

serialization testing

npm install remark-lint-frontmatter-schema

github ↗package ↗

INSTALL

IMPORT

SIG · REMARK-LINT-FRONTM

remark-lint-frontmatter-schema

serializationjavascriptv3.15.4

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

remarkLintFrontmatterSchema

✓ import remarkLintFrontmatterSchema from 'remark-lint-frontmatter-schema'

✗ const { remarkLintFrontmatterSchema } = require('remark-lint-frontmatter-schema')

Default export is a function that returns a remark plugin. CommonJS require is also supported.

default

✓ const plugin = require('remark-lint-frontmatter-schema')

✗ const { default: plugin } = require('remark-lint-frontmatter-schema')

In CJS, default export is accessed directly via require, not destructured.

remarkLintFrontmatterSchema

✓ import remarkLintFrontmatterSchema from 'remark-lint-frontmatter-schema'

✗ import { remarkLintFrontmatterSchema } from 'remark-lint-frontmatter-schema'

This is a default export, not named export. Named import will result in undefined.

Set up a remark processor with remark-lint and remark-lint-frontmatter-schema, validate frontmatter against a JSON schema, and see lint messages.

import { readSync } from 'fs'; import { remark } from 'remark'; import remarkLint from 'remark-lint'; import remarkLintFrontmatterSchema from 'remark-lint-frontmatter-schema'; const processor = remark() .use(remarkLint) .use(remarkLintFrontmatterSchema, { schemas: [ { pattern: '*.md', schema: { type: 'object', properties: { title: { type: 'string' }, date: { type: 'string', format: 'date' } }, required: ['title', 'date'] } } ] }); const result = processor.processSync( '---\ntitle: Hello\ndate: 2023-01-01\n---\n# Content' ); console.log(result.messages); // [] (no errors) const result2 = processor.processSync( '---\ntitle: 123\ndate: not-a-date\n---\n# Content' ); console.log(result2.messages); // [ { message: 'title: must be string', ... } ]

Debug

Known issues

gotchaSchema must be a valid JSON Schema (draft-07) object. Invalid schemas will fail silently or throw obscure errors.

fix

Validate your schema against JSON Schema meta-schema before use.

affects: >=3.0.0

breakingFrom v3.0.0, the plugin changed from a custom configuration format to using a `schemas` array with `pattern` and `schema` objects. Old `schemaPath` option removed.

fix

Update configuration to new format: { schemas: [{ pattern: '*.md', schema: {...} }] }

affects: >=3.0.0

deprecatedThe `schemaPath` option was deprecated in v3.0.0 and removed in v3.14.0.

fix

Use `schemas` array with inline schema or `$ref` to external file.

affects: >=3.14.0

gotchaIn-file `$schema` key in frontmatter is only supported if the schema URL is an HTTP(S) URL or a relative file path. Absolute file paths are not supported.

fix

Use relative paths (e.g., `$schema: ./schema.json`) or a URL. For local schemas, ensure the file resolves relative to the working directory.

affects: >=3.13.0

gotchaThe plugin only validates the first YAML block in the Markdown file even if multiple YAML blocks exist. It treats the first YAML as frontmatter.

fix

Ensure that only one YAML frontmatter block exists, or the first one is the intended frontmatter.

affects: >=3.15.3

Errors

Common errors & fixes

Error: Cannot find module 'remark-lint-frontmatter-schema'

Package not installed or incorrect import path.

fix

Run `npm install remark-lint-frontmatter-schema` and ensure import path is correct.

TypeError: plugin is not a function

Importing the module incorrectly (e.g., named import instead of default).

fix

Use default import: `import plugin from 'remark-lint-frontmatter-schema'`

ValidationError: data must have required property 'title'

Frontmatter missing required fields as per schema.

fix

Add the missing required fields to the frontmatter YAML.

Error: No schema defined for pattern '*.md'

Glob pattern in configuration doesn't match any defined schema.

fix

Check the `schemas` array configuration and ensure the pattern matches the file being processed.

Upgrade

Version history

3.15.4latest on npm

Audit

Dependencies

unifiedrequiredRequired for remark-lint plugin integration

remark-lintrequiredRequired for lint rule base

ajvrequiredUsed for JSON Schema validation

yamlrequiredUsed to parse frontmatter YAML

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/JulianCataldo/remark-lint-frontmatter-schema ↗

packagehttps://www.npmjs.com/package/remark-lint-frontmatter-schema ↗