@theia/core/src/common/markdown-rendering/markdown-string.spec.ts

Theia is a cloud & desktop IDE framework implemented in TypeScript.

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import { expect } from 'chai';
import { MarkdownStringImpl } from './markdown-string';

describe('MarkdownStringImpl#appendCodeblock', () => {

    it('uses a triple-backtick fence for code without backticks', () => {
        const md = new MarkdownStringImpl();
        md.appendCodeblock('json', '{ "type": "adaptive" }');
        expect(md.value).to.equal('\n```json\n{ "type": "adaptive" }\n```\n');
    });

    it('uses a longer fence when the code contains a triple-backtick run', () => {
        const md = new MarkdownStringImpl();
        const code = 'before\n```json\n{ "x": 1 }\n```\nafter';
        md.appendCodeblock('', code);
        // The fence must be at least 4 backticks so the inner ``` cannot close it.
        expect(md.value).to.equal('\n````\n' + code + '\n````\n');
    });

    it('grows the fence to be longer than the longest backtick run inside the code', () => {
        const md = new MarkdownStringImpl();
        const code = 'a ```` b ``` c';
        md.appendCodeblock('', code);
        // Longest run is 4, so fence must be 5.
        expect(md.value).to.equal('\n`````\n' + code + '\n`````\n');
    });

    it('still uses a triple-backtick fence when only single/double backticks appear', () => {
        const md = new MarkdownStringImpl();
        const code = 'inline `code` and ``double`` only';
        md.appendCodeblock('', code);
        expect(md.value).to.equal('\n```\n' + code + '\n```\n');
    });
});