it("returns the text unchanged when there is no markdown", () => {

const { text, ranges } = extractMarkdownFormatRuns("plain text reply");

expect(text).toBe("plain text reply");

expect(ranges).toEqual([]);

expect(ranges).toStrictEqual([]);

});

it("extracts a bold span", () => {

it("respects word boundaries on single-underscore italics", () => {

const { text, ranges } = extractMarkdownFormatRuns("snake_case_var ok");

expect(text).toBe("snake_case_var ok");

expect(ranges).toEqual([]);

expect(ranges).toStrictEqual([]);

});

it("treats single-underscore as italic when surrounded by whitespace", () => {

it("does not treat empty marker pairs as formatting", () => {

const { text, ranges } = extractMarkdownFormatRuns("** ** literal");

expect(text).toBe("** ** literal");

expect(ranges).toEqual([]);

expect(ranges).toStrictEqual([]);

});

it("leaves a lone asterisk alone", () => {

const { text, ranges } = extractMarkdownFormatRuns("price * quantity");

expect(text).toBe("price * quantity");

expect(ranges).toEqual([]);

expect(ranges).toStrictEqual([]);

});

it("computes ranges in output coordinates, not input", () => {

it("respects word boundaries on double-underscore underline", () => {

const { text, ranges } = extractMarkdownFormatRuns("def __init__(self):");

expect(text).toBe("def __init__(self):");

expect(ranges).toEqual([]);

expect(ranges).toStrictEqual([]);

});

it("does not leak literal asterisks from triple markers when intent is unclear", () => {