feat: add support for TOML frontmatter in markdown processing

.changeset/orange-dogs-pull.md

@@ -0,0 +1,6 @@
+---
+"@studiocms/markdown-remark-processor-web": minor
+"@studiocms/markdown-remark-processor": minor
+---
+
+Update to add support for TOML frontmatter to match Astro's markdown-remark package compat

package.json

@@ -28,12 +28,12 @@
     "@changesets/cli": "^2.27.11",
     "@changesets/config": "^3.0.5",
     "@types/node": "^22.10.7",
-    "@vitest/ui": "3.0.2",
-    "esbuild": "^0.24.2",
+    "@vitest/ui": "3.0.5",
+    "esbuild": "^0.25.0",
     "jest-extended": "^4.0.2",
     "pkg-pr-new": "^0.0.39",
     "run-scripts": "workspace:*",
     "typescript": "^5.7.3",
-    "vitest": "^3.0.2"
+    "vitest": "^3.0.5"
   }
 }

packages/markdown-remark-processor-web/package.json

@@ -49,6 +49,7 @@
     "remark-rehype": "^11.1.1",
     "remark-smartypants": "^3.0.2",
     "shiki": "^1.23.1",
+    "smol-toml": "^1.3.1",
     "unified": "^11.0.5",
     "unist-util-remove-position": "^5.0.0",
     "unist-util-visit": "^5.0.0",

packages/markdown-remark-processor-web/src/frontmatter.ts

@@ -1,4 +1,5 @@
 import yaml from 'js-yaml';
+import * as toml from 'smol-toml';
 
 // biome-ignore lint/suspicious/noExplicitAny: <explanation>
 export function isFrontmatterValid(frontmatter: Record<string, any>): boolean {
@@ -11,15 +12,20 @@ export function isFrontmatterValid(frontmatter: Record<string, any>): boolean {
 	return typeof frontmatter === 'object' && frontmatter !== null;
 }
 
-// Capture frontmatter wrapped with `---`, including any characters and new lines within it.
-// Only capture if `---` exists near the top of the file, including:
+// Capture frontmatter wrapped with `---` or `+++`, including any characters and new lines within it.
+// Only capture if `---` or `+++` exists near the top of the file, including:
 // 1. Start of file (including if has BOM encoding)
 // 2. Start of file with any whitespace (but `---` must still start on a new line)
-const frontmatterRE = /(?:^\uFEFF?|^\s*\n)---([\s\S]*?\n)---/;
+const frontmatterRE = /(?:^\uFEFF?|^\s*\n)(?:---|\+\+\+)([\s\S]*?\n)(?:---|\+\+\+)/;
+const frontmatterTypeRE = /(?:^\uFEFF?|^\s*\n)(---|\+\+\+)/;
 export function extractFrontmatter(code: string): string | undefined {
 	return frontmatterRE.exec(code)?.[1];
 }
 
+function getFrontmatterParser(code: string): [string, (str: string) => unknown] {
+	return frontmatterTypeRE.exec(code)?.[1] === '+++' ? ['+++', toml.parse] : ['---', yaml.load];
+}
+
 export interface ParseFrontmatterOptions {
 	/**
 	 * How the frontmatter should be handled in the returned `content` string.
@@ -69,7 +75,8 @@ export function parseFrontmatter(
 		return { frontmatter: {}, rawFrontmatter: '', content: code };
 	}
 
-	const parsed = yaml.load(rawFrontmatter);
+	const [delims, parser] = getFrontmatterParser(code);
+	const parsed = parser(rawFrontmatter);
 	// biome-ignore lint/suspicious/noExplicitAny: <explanation>
 	const frontmatter = (parsed && typeof parsed === 'object' ? parsed : {}) as Record<string, any>;
 
@@ -79,16 +86,19 @@ export function parseFrontmatter(
 			content = code;
 			break;
 		case 'remove':
-			content = code.replace(`---${rawFrontmatter}---`, '');
+			content = code.replace(`${delims}${rawFrontmatter}${delims}`, '');
 			break;
 		case 'empty-with-spaces':
 			content = code.replace(
-				`---${rawFrontmatter}---`,
+				`${delims}${rawFrontmatter}${delims}`,
 				`   ${rawFrontmatter.replace(/[^\r\n]/g, ' ')}   `
 			);
 			break;
 		case 'empty-with-lines':
-			content = code.replace(`---${rawFrontmatter}---`, rawFrontmatter.replace(/[^\r\n]/g, ''));
+			content = code.replace(
+				`${delims}${rawFrontmatter}${delims}`,
+				rawFrontmatter.replace(/[^\r\n]/g, '')
+			);
 			break;
 	}
 

packages/markdown-remark-processor/package.json

@@ -54,14 +54,14 @@
     "remark-rehype": "^11.1.1",
     "remark-smartypants": "^3.0.2",
     "shiki": "^1.23.1",
+    "smol-toml": "^1.3.1",
     "unified": "^11.0.5",
     "unist-util-remove-position": "^5.0.0",
     "unist-util-visit": "^5.0.0",
     "unist-util-visit-parents": "^6.0.1",
     "vfile": "^6.0.3"
   },
   "devDependencies": {
-    "@inox-tools/astro-tests": "^0.2.2",
     "@types/estree": "^1.0.6",
     "@types/html-escaper": "^3.0.2",
     "@types/hast": "^3.0.4",

packages/markdown-remark-processor/src/frontmatter.ts

@@ -1,4 +1,5 @@
 import yaml from 'js-yaml';
+import * as toml from 'smol-toml';
 
 // biome-ignore lint/suspicious/noExplicitAny: <explanation>
 export function isFrontmatterValid(frontmatter: Record<string, any>): boolean {
@@ -11,15 +12,20 @@ export function isFrontmatterValid(frontmatter: Record<string, any>): boolean {
 	return typeof frontmatter === 'object' && frontmatter !== null;
 }
 
-// Capture frontmatter wrapped with `---`, including any characters and new lines within it.
-// Only capture if `---` exists near the top of the file, including:
+// Capture frontmatter wrapped with `---` or `+++`, including any characters and new lines within it.
+// Only capture if `---` or `+++` exists near the top of the file, including:
 // 1. Start of file (including if has BOM encoding)
 // 2. Start of file with any whitespace (but `---` must still start on a new line)
-const frontmatterRE = /(?:^\uFEFF?|^\s*\n)---([\s\S]*?\n)---/;
+const frontmatterRE = /(?:^\uFEFF?|^\s*\n)(?:---|\+\+\+)([\s\S]*?\n)(?:---|\+\+\+)/;
+const frontmatterTypeRE = /(?:^\uFEFF?|^\s*\n)(---|\+\+\+)/;
 export function extractFrontmatter(code: string): string | undefined {
 	return frontmatterRE.exec(code)?.[1];
 }
 
+function getFrontmatterParser(code: string): [string, (str: string) => unknown] {
+	return frontmatterTypeRE.exec(code)?.[1] === '+++' ? ['+++', toml.parse] : ['---', yaml.load];
+}
+
 export interface ParseFrontmatterOptions {
 	/**
 	 * How the frontmatter should be handled in the returned `content` string.
@@ -69,7 +75,8 @@ export function parseFrontmatter(
 		return { frontmatter: {}, rawFrontmatter: '', content: code };
 	}
 
-	const parsed = yaml.load(rawFrontmatter);
+	const [delims, parser] = getFrontmatterParser(code);
+	const parsed = parser(rawFrontmatter);
 	// biome-ignore lint/suspicious/noExplicitAny: <explanation>
 	const frontmatter = (parsed && typeof parsed === 'object' ? parsed : {}) as Record<string, any>;
 
@@ -79,16 +86,19 @@ export function parseFrontmatter(
 			content = code;
 			break;
 		case 'remove':
-			content = code.replace(`---${rawFrontmatter}---`, '');
+			content = code.replace(`${delims}${rawFrontmatter}${delims}`, '');
 			break;
 		case 'empty-with-spaces':
 			content = code.replace(
-				`---${rawFrontmatter}---`,
+				`${delims}${rawFrontmatter}${delims}`,
 				`   ${rawFrontmatter.replace(/[^\r\n]/g, ' ')}   `
 			);
 			break;
 		case 'empty-with-lines':
-			content = code.replace(`---${rawFrontmatter}---`, rawFrontmatter.replace(/[^\r\n]/g, ''));
+			content = code.replace(
+				`${delims}${rawFrontmatter}${delims}`,
+				rawFrontmatter.replace(/[^\r\n]/g, '')
+			);
 			break;
 	}
 

packages/markdown-remark/package.json

@@ -54,7 +54,7 @@
     "ultrahtml": "^1.5.3"
   },
   "devDependencies": {
-    "@inox-tools/astro-tests": "^0.2.2"
+    "@inox-tools/astro-tests": "0.2.2"
   },
   "publishConfig": {
     "provenance": true

packages/markdown-remark/tests/astro-integration.test.ts

@@ -2,7 +2,7 @@ import { loadFixture } from '@inox-tools/astro-tests/astroFixture';
 import { afterAll, beforeAll, describe, expect, test } from 'vitest';
 
 const fixture = await loadFixture({
-	root: './fixture/astro',
+	root: './fixture/astro/',
 });
 
 describe('Markdown-Remark Astro Integration Tests', () => {

packages/markdown-remark/tests/fixture/astro/package.json

@@ -13,6 +13,6 @@
   },
   "dependencies": {
     "@studiocms/markdown-remark": "workspace:*",
-    "astro": "^5.1.7"
+    "astro": "^5.2.5"
   }
 }