diff --git a/static_src/shared/md-helper.test.js b/static_src/shared/md-helper.test.js
new file mode 100644
index 0000000..9f7dba1
--- /dev/null
+++ b/static_src/shared/md-helper.test.js
@@ -0,0 +1,90 @@
+import {assert} from 'chai';
+import {renderMarkdown, shouldRenderMarkdown} from './md-helper.js';
+
+describe('shouldRenderMarkdown', () => {
+  it('defaults to false', () => {
+    const actual = shouldRenderMarkdown();
+    assert.isFalse(actual);
+  });
+
+  it('returns true for enabled projects', () => {
+    const actual = shouldRenderMarkdown({project:'astor',
+      availableProjects: new Set(['astor'])});
+    assert.isTrue(actual);
+  });
+
+  it('returns false for disabled projects', () => {
+    const actual = shouldRenderMarkdown({project:'hazelnut',
+      availableProjects: new Set(['astor'])});
+    assert.isFalse(actual);
+  });
+
+  it('user pref can disable markdown', () => {
+    const actual = shouldRenderMarkdown({project:'astor',
+      enabledProjects: new Set(['astor']), enabled: false});
+    assert.isFalse(actual);
+  });
+});
+
+describe('renderMarkdown', () => {
+  it('can render empty string', () => {
+    const actual = renderMarkdown('');
+    assert.equal(actual, '');
+  });
+
+  it('can render basic string', () => {
+    const actual = renderMarkdown('hello world');
+    assert.equal(actual, '<p>hello world</p>\n');
+  });
+
+  it('can render lists', () => {
+    const input = '* First item\n* Second item\n* Third item\n* Fourth item';
+    const actual = renderMarkdown(input);
+    const expected = '<ul>\n<li>First item</li>\n<li>Second item</li>\n' +
+        '<li>Third item</li>\n<li>Fourth item</li>\n</ul>\n';
+    assert.equal(actual, expected);
+  });
+
+  it('can render headings', () => {
+    const actual = renderMarkdown('# Heading level 1\n\n## Heading level 2');
+    assert.equal(actual,
+        '<h1>Heading level 1</h1>\n<h2>Heading level 2</h2>\n');
+  });
+
+  describe('can render links', () => {
+    it('for simple links', () => {
+      const actual = renderMarkdown('[clickme](http://google.com)');
+      const expected = `<p><span class="annotated-link"><a title="" ` +
+          `href="http://google.com"><span class="material-icons link">` +
+          `link</span>clickme</a><span class="tooltip">Link destination: ` +
+          `http://google.com</span></span></p>\n`;
+      assert.equal(actual, expected);
+    });
+
+    it('and indicates malformed link', () => {
+      const actual = renderMarkdown('[clickme](google.com)');
+      const expected = `<p><span class="annotated-link"><a title="" ` +
+          `href="google.com"><span class="material-icons link_off">link_off` +
+          `</span>clickme</a><span class="tooltip">Link may be malformed: ` +
+          `google.com</span></span></p>\n`;
+      assert.equal(actual, expected);
+    });
+  });
+
+  it('preserves bolding from description templates', () => {
+    const input = `<b>What's the problem?</b>\n<b>1.</b> A\n<b>2.</b> B`;
+    const actual = renderMarkdown(input);
+    const expected = `<p><strong>What's the problem?</strong>\n<strong>1.` +
+        `</strong> A\n<strong>2.</strong> B</p>\n`;
+    assert.equal(actual, expected);
+  });
+
+  it('escapes HTML content', () => {
+    let actual = renderMarkdown('<input></input>');
+    assert.equal(actual, '<p>&lt;input&gt;&lt;/input&gt;</p>\n');
+
+    actual = renderMarkdown('<a href="https://google.com">clickme</a>');
+    assert.equal(actual,
+        '<p>&lt;a href="https://google.com"&gt;clickme&lt;/a&gt;</p>\n');
+  });
+});