zulip/frontend_tests/node_tests/fenced_code.js

const fenced_code = zrequire("fenced_code", "shared/js/fenced_code");

run_test("get_unused_fence", () => {
    assert.equal(fenced_code.get_unused_fence("```js\nsomething\n```"), "`".repeat(4));
    assert.equal(fenced_code.get_unused_fence("````\nsomething\n````"), "`".repeat(5));
    assert.equal(fenced_code.get_unused_fence("```\n````\n``````"), "`".repeat(7));
    assert.equal(fenced_code.get_unused_fence("~~~\nsomething\n~~~"), "`".repeat(3));
    assert.equal(
        fenced_code.get_unused_fence("```code\nterminating fence is indented and longer\n   ````"),
        "`".repeat(5),
    );
    assert.equal(
        fenced_code.get_unused_fence("```code\nterminating fence is extra indented\n    ````"),
        "`".repeat(4),
    );
    let large_testcase = "";
    // ```
    // ````
    // `````
    // ... up to N chars
    // We insert a N + 1 character fence.
    for (let i = 3; i <= 20; i += 1) {
        large_testcase += "`".repeat(i) + "\n";
    }
    assert.equal(fenced_code.get_unused_fence(large_testcase), "`".repeat(21));
});