});

it("M-03 only `---` (single fence, no content)", () => {

expect(() => parseMd("---\n")).not.toThrow();

const { ast, diagnostics } = parseMd("---\n");

expect(diagnostics.map((diagnostic) => diagnostic.code)).toContain("OC_FRONTMATTER_UNCLOSED");

expect(ast.frontmatter).toEqual([]);

expect(ast.preamble).toBe("---\n");

});

it("M-04 only `---\\n---`", () => {

it("M-05 binary-ish bytes (non-ASCII control chars)", () => {

const raw = "## H\n\x00\x01\x02\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast, diagnostics } = parseMd(raw);

expect(diagnostics).toEqual([]);

expect(ast.blocks[0]?.bodyText).toBe("\x00\x01\x02\n");

});

it("M-06 very long single line (10k chars)", () => {

it("M-09 unclosed code fence", () => {

const raw = "## H\n```\nbody\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.blocks[0]?.bodyText).toBe("```\nbody\n");

});

it("M-10 mismatched fence (open with ``` close with ~~~)", () => {

const raw = "## H\n```\nbody\n~~~\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.blocks[0]?.bodyText).toBe("```\nbody\n~~~\n");

});

it("M-11 nested fences (treated linearly, not nested)", () => {

const raw = "## H\n```\n```\nstill-in-second\n```\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.blocks[0]?.bodyText).toBe("```\n```\nstill-in-second\n```\n");

});

it("M-12 empty file", () => {

it("M-15 file with mixed indentation extremes (tabs, spaces, mixed)", () => {

const raw = "## H\n\t- tabbed\n - spaced\n\t - mixed\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.blocks[0]?.bodyText).toBe("\t- tabbed\n - spaced\n\t - mixed\n");

});

it("M-16 frontmatter with frontmatter-shaped content inside (---)", () => {

});

it("M-19 file with just whitespace", () => {

expect(() => parseMd(" \n\t\n \n")).not.toThrow();

const { ast, diagnostics } = parseMd(" \n\t\n \n");

expect(diagnostics).toEqual([]);

expect(ast.preamble).toBe(" \n\t\n \n");

expect(ast.blocks).toEqual([]);

});

it("M-20 file with only BOM", () => {

it("M-21 file mixing BOM + frontmatter + body + sections", () => {

const raw = "---\nk: v\n---\n\nbody\n## Section\n- item\n";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.frontmatter[0]?.value).toBe("v");

expect(ast.blocks[0]?.heading).toBe("Section");

expect(ast.blocks[0]?.items[0]?.text).toBe("item");

});

it("M-22 line endings: legacy CR-only (Mac classic)", () => {

// Our regex /\r?\n/ doesn't split on CR-only. Treats whole as one line.

const raw = "line1\rline2\r## Heading\r";

expect(() => parseMd(raw)).not.toThrow();

const { ast } = parseMd(raw);

expect(ast.preamble).toBe(raw);

expect(ast.blocks).toEqual([]);

});

it("M-23 100 KB file", () => {

}

}

const raw = lines.join("\n");

expect(() => parseMd(raw)).not.toThrow();

const { ast, diagnostics } = parseMd(raw);

expect(diagnostics).toEqual([]);

expect(ast.blocks).toHaveLength(1000);

expect(ast.blocks[999]?.items).toHaveLength(5);

});

});