Repository: eslint/eslint
File: docs/.eleventy.js (JavaScript)

Code before:
                        </div>
                    </div>
                </aside>
        `.trim();
    }

    /**
     * Encodes text in the base 64 format used in playground URL params.
     * @param {string} text Text to be encoded to base 64.
     * @see https://github.com/eslint/eslint.org/blob/1b2f2aabeac2955a076d61788da8a0008bca6fb6/src/playground/utils/unicode.js
     * @returns {string} The base 64 encoded equivalent of the text.
     */
    function encodeToBase64(text) {
        /* global btoa -- It does exist, and is what the playground uses. */
        return btoa(unescape(encodeURIComponent(text)));
    }

    const withPlaygroundRender = {
        render(tokens, index) {
            if (tokens[index].nesting !== 1) {
                return "</div>";
            }

            const state = encodeToBase64(
                JSON.stringify({
                    text: tokens[index + 1].content
                })
            );

            return `
                <div class="with-playground-link">
                    <a class="open-in-playground" href="/play#${state}" target="_blank">
                        Open in Playground ↗️
                    </a>
            `.trim();
        }
    };

    const markdownIt = require("markdown-it");
    const md = markdownIt({ html: true, linkify: true, typographer: true, highlight: (str, lang) => highlighter(md, str, lang) })
        .use(markdownItAnchor, {
            slugify: s => slug(s)
        })
        .use(markdownItContainer, "img-container", {})
        .use(markdownItContainer, "correct", withPlaygroundRender)
        .use(markdownItContainer, "incorrect", withPlaygroundRender)
        .use(markdownItContainer, "warning", {
            render(tokens, idx) {
                return generateAlertMarkup("warning", tokens, idx);
            }
        })

Review comment (suggestion):
@mdjermanovic /co. from https://github.com/eslint/eslint/issues/17018#issuecomment-1523747750, is there a way you'd suggest encoding `parserOptions` settings such as `sourceType: "script"`? I've never had to do that with an ESLint configuration comment.

Code after:
                        </div>
                    </div>
                </aside>
        `.trim();
    }

    /**
     * Encodes text in the base 64 format used in playground URL params.
     * @param {string} text Text to be encoded to base 64.
     * @see https://github.com/eslint/eslint.org/blob/1b2f2aabeac2955a076d61788da8a0008bca6fb6/src/playground/utils/unicode.js
     * @returns {string} The base 64 encoded equivalent of the text.
     */
    function encodeToBase64(text) {
        /* global btoa -- It does exist, and is what the playground uses. */
        return btoa(unescape(encodeURIComponent(text)));
    }

    /**
     * Creates markdownItContainer settings for a playground-linked codeblock.
     * @param {string} name Plugin name and class name to add to the code block.
     * @returns {[string, object]} Plugin name and options for markdown-it.
     */
    function withPlaygroundRender(name) {
        return [
            name,
            {
                render(tokens, index) {
                    if (tokens[index].nesting !== 1) {
                        return "</div>";
                    }

                    // See https://github.com/eslint/eslint.org/blob/ac38ab41f99b89a8798d374f74e2cce01171be8b/src/playground/App.js#L44
                    const parserOptions = tokens[index].info?.split("correct ")[1]?.trim();
                    const { content } = tokens[index + 1];
                    const state = encodeToBase64(
                        JSON.stringify({
                            ...(parserOptions && { options: { parserOptions: JSON.parse(parserOptions) } }),
                            text: content
                        })
                    );
                    const prefix = process.env.CONTEXT && process.env.CONTEXT !== "deploy-preview"
                        ? ""
                        : "https://eslint.org";

                    return `
                        <div class="${name}">
                            <a class="c-btn c-btn--secondary c-btn--playground" href="${prefix}/play#${state}" target="_blank">
                                Open in Playground
                            </a>
                    `.trim();
                }