fix: handle CR in MarkdownSourceCode and Front Matter util (#554)

* fix: add CR to `MarkdownSourceCode` * wip: util * wip * wip: typo

Author: lumirlumir

src/language/markdown-source-code.js

@@ -13,6 +13,7 @@ import {
 ConfigCommentParser,
 Directive,
 } from "@eslint/plugin-kit";
+import { lineEndingPattern } from "../util.js";
 
 //-----------------------------------------------------------------------------
 // Types
@@ -152,7 +153,7 @@ export class MarkdownSourceCode extends TextSourceCodeBase {
  * @param {Root} options.ast The root AST node.
  */
 constructor({ text, ast }) {
-super({ ast, text });
+super({ ast, text, lineEndingPattern });
 this.ast = ast;
 
 // need to traverse the source code to get the inline config nodes

src/util.js

@@ -7,6 +7,12 @@
 // Regex Patterns
 //-----------------------------------------------------------------------------
 
+/**
+ * Line ending pattern to match all line endings (CRLF, CR, LF). (CommonMark spec)
+ * @see https://spec.commonmark.org/0.31.2/#line-ending
+ */
+export const lineEndingPattern = /\r\n|[\r\n]/u;
+
 /**
  * CommonMark does not allow any white space between the brackets in a reference link.
  * If that pattern is detected, then it's treated as text and not as a link. This pattern
@@ -24,16 +30,16 @@ export const htmlCommentPattern = /<!--[\s\S]*?-->/gu;
 //-----------------------------------------------------------------------------
 
 /**
- * Checks if a frontmatter block contains a title matching the given pattern
- * @param {string} value The frontmatter content
- * @param {RegExp|null} pattern The pattern to match against
- * @returns {boolean} Whether a title was found
+ * Checks if a frontmatter block contains a title matching the given pattern.
+ * @param {string} value The frontmatter content.
+ * @param {RegExp|null} pattern The pattern to match against.
+ * @returns {boolean} Whether a title was found.
  */
 export function frontmatterHasTitle(value, pattern) {
 if (!pattern) {
 return false;
 }
-const lines = value.split("\n");
+const lines = value.split(lineEndingPattern);
 for (const line of lines) {
 if (pattern.test(line)) {
 return true;

tests/language/markdown-source-code.test.js

@@ -66,6 +66,67 @@ describe("MarkdownSourceCode", () => {
 sourceCode = new MarkdownSourceCode({ text: markdownText, ast });
 });
 
+describe("constructor", () => {
+it("should create a MarkdownSourceCode instance", () => {
+assert.strictEqual(
+sourceCode.constructor.name,
+"MarkdownSourceCode",
+);
+assert.strictEqual(sourceCode.ast, ast);
+assert.strictEqual(sourceCode.text, markdownText);
+});
+});
+
+describe("lines", () => {
+it("should parse CRLF line endings", () => {
+const text = "lumir\r\nlumir";
+const sourceCodeWithCRLF = new MarkdownSourceCode({
+text,
+ast: fromMarkdown(text),
+});
+
+assert.deepStrictEqual(sourceCodeWithCRLF.lines, [
+"lumir",
+"lumir",
+]);
+});
+
+it("should parse CR line endings", () => {
+const text = "lumir\rlumir";
+const sourceCodeWithCR = new MarkdownSourceCode({
+text,
+ast: fromMarkdown(text),
+});
+
+assert.deepStrictEqual(sourceCodeWithCR.lines, ["lumir", "lumir"]);
+});
+
+it("should parse LF line endings", () => {
+const text = "lumir\nlumir";
+const sourceCodeWithLF = new MarkdownSourceCode({
+text,
+ast: fromMarkdown(text),
+});
+
+assert.deepStrictEqual(sourceCodeWithLF.lines, ["lumir", "lumir"]);
+});
+
+it("should parse CRLF CR LF line endings", () => {
+const text = "lumir\r\nlumir\rlumir\nlumir";
+const sourceCodeWithCRLFCRLF = new MarkdownSourceCode({
+text,
+ast: fromMarkdown(text),
+});
+
+assert.deepStrictEqual(sourceCodeWithCRLFCRLF.lines, [
+"lumir",
+"lumir",
+"lumir",
+"lumir",
+]);
+});
+});
+
 describe("getText()", () => {
 it("should return the text of the Markdown source code", () => {
 assert.strictEqual(sourceCode.getText(), markdownText);

tests/util.test.js

@@ -36,7 +36,25 @@ describe("util", () => {
 );
 });
 
-it("should return true if the pattern matches any line in multiline frontmatter", () => {
+it("should return true if the pattern matches any line in multiline frontmatter (CRLF)", () => {
+const frontmatter = [
+"description: Test",
+"title: My Document",
+"author: lumirlumir",
+].join("\r\n");
+assert.strictEqual(frontmatterHasTitle(frontmatter, pattern), true);
+});
+
+it("should return true if the pattern matches any line in multiline frontmatter (CR)", () => {
+const frontmatter = [
+"description: Test",
+"title: My Document",
+"author: lumirlumir",
+].join("\r");
+assert.strictEqual(frontmatterHasTitle(frontmatter, pattern), true);
+});
+
+it("should return true if the pattern matches any line in multiline frontmatter (LF)", () => {
 const frontmatter = [
 "description: Test",
 "title: My Document",