blog/test/excerpt-markdown-links.test.js

import test from "node:test";
import assert from "node:assert/strict";
import nunjucks from "nunjucks";
import path from "node:path";
import { filters } from "../src/_filters/index.js";

const includesDir = path.resolve("src/_includes");
const markdownExcerpt = "Read the [deployment guide](/guides/deploy/) before continuing.";

function renderTemplate(template, context) {
  const env = new nunjucks.Environment(new nunjucks.FileSystemLoader(includesDir), { autoescape: false });
  for (const [name, filter] of Object.entries(filters)) {
    env.addFilter(name, filter);
  }

  return env.render(template, context);
}

test("Excerpt Markdown: renders Markdown links as safe inline HTML", () => {
  assert.equal(
    filters.renderExcerptMarkdown(markdownExcerpt),
    'Read the <a href="/guides/deploy/">deployment guide</a> before continuing.'
  );
});

test("Excerpt Markdown: renders links in post-card previews", () => {
  const output = renderTemplate("partials/post-card.njk", {
    post: {
      fileSlug: "example-dispatch",
      url: "/dispatches/example/",
      date: "2026-10-06",
      data: {
        title: "Example dispatch",
        excerpt: markdownExcerpt,
        tags: ["systems"]
      },
      templateContent: "A short article."
    }
  });

  assert.match(output, /<p class="feed-excerpt">\s*Read the <a href="\/guides\/deploy\/">deployment guide<\/a> before continuing\.\s*<\/p>/);
});

test("Excerpt Markdown: renders links in featured previews and escapes raw HTML", () => {
  const output = renderTemplate("partials/featured-card.njk", {
    collections: {
      posts: [{
        url: "/dispatches/example/",
        date: "2026-10-06",
        data: {
          featured: true,
          tags: ["systems"],
          title: "Example dispatch",
          excerpt: `${markdownExcerpt} <script>alert('unsafe')</script>`
        },
        templateContent: ""
      }]
    }
  });

  assert.match(output, /<a href="\/guides\/deploy\/">deployment guide<\/a>/);
  assert.match(output, /&lt;script&gt;alert\('unsafe'\)&lt;\/script&gt;/);
  assert.doesNotMatch(output, /<script>/);
});