diff --git a/test/integration/test_wysiwyg.js b/test/integration/test_wysiwyg.js
index f0349b0..02cc4b3 100644
--- a/test/integration/test_wysiwyg.js
+++ b/test/integration/test_wysiwyg.js
@@ -26,6 +26,10 @@ const PORT      = (() => {
     const portArg = process.argv.find(arg => arg.startsWith('--port='));
     return portArg ? parseInt(portArg.split('=')[1]) : 5023;
 })();
+const FILTER    = (() => {
+    const filterArg = process.argv.find(arg => arg.startsWith('--filter='));
+    return filterArg ? filterArg.split('=')[1] : null;
+})();
 const DELAY     = 20;  // ms between keystrokes
 
 // ── State ─────────────────────────────────────────────────────────────────────
@@ -169,6 +173,9 @@ function assert(condition, message) {
 }
 
 async function test(name, fn) {
+    if (FILTER && !name.toLowerCase().includes(FILTER.toLowerCase())) {
+        return;
+    }
     try {
         await fn();
         passed++;
@@ -286,6 +293,60 @@ async function runTests() {
         assert(markdown === '***both***', `Expected "***both***", got: "${markdown}"`);
     });
 
+    await test('nested bold and italic are handled correctly', async() => {
+        const NESTED_CASES = [
+            {
+                name: 'close-side ambiguity, outer=bold (bold *italic***)',
+                markdown: '**bold *italic***',
+                outerClass: 'md-bold',
+                innerClass: 'md-italic',
+            },
+            {
+                name: 'close-side ambiguity, outer=italic (*italic **bold***)',
+                markdown: '*italic **bold***',
+                outerClass: 'md-italic',
+                innerClass: 'md-bold',
+            },
+            {
+                name: 'open-side ambiguity, outer=bold (***italic* bold**)',
+                markdown: '***italic* bold**',
+                outerClass: 'md-bold',
+                innerClass: 'md-italic',
+            },
+            {
+                name: 'open-side ambiguity, outer=italic (***bold** italic*)',
+                markdown: '***bold** italic*',
+                outerClass: 'md-italic',
+                innerClass: 'md-bold',
+            },
+        ];
+        
+        for (const testCase of NESTED_CASES) {
+            await test(testCase.name, async () => {
+                await resetEditor();
+                await typeString(testCase.markdown);
+        
+                const markdown = await getMarkdown();
+                assert(
+                    markdown === testCase.markdown,
+                    `Round-trip failed.\nExpected: "${testCase.markdown}"\nGot:      "${markdown}"`
+                );
+        
+                const html = await getHTML();
+                const outerIndex = html.indexOf(testCase.outerClass);
+                const innerIndex = html.indexOf(testCase.innerClass);
+                assert(
+                    outerIndex !== -1 && innerIndex !== -1,
+                    `Missing expected classes (${testCase.outerClass}, ${testCase.innerClass}) in: ${html}`
+                );
+                assert(
+                    outerIndex < innerIndex,
+                    `Expected ${testCase.outerClass} to wrap (appear before) ${testCase.innerClass} in: ${html}`
+                );
+            });
+        }
+    });
+
     await test('`code` produces md-code span', async () => {
         await resetEditor();
         await typeString('`code`');