feat: improve the Markdown underscore rendering

Author: qorzj

src/tests/markdown.test.ts

@@ -42,6 +42,21 @@ test("renderMarkdown styles inline code without removing it", () => {
   assert.equal(result.includes("npm install"), true);
 });
 
+test("renderMarkdown preserves underscores inside inline code", () => {
+  const source =
+    "Use `redo_completed_tasks2_1min`, replace `execute_query` with `select_one`/`select_all`, and check `ocr_result`.";
+  const result = stripAnsi(renderMarkdown(source));
+  assert.equal(
+    result,
+    "Use redo_completed_tasks2_1min, replace execute_query with select_one/select_all, and check ocr_result."
+  );
+});
+
+test("renderMarkdown preserves underscores in plain identifiers", () => {
+  const result = stripAnsi(renderMarkdown("Check redo_completed_tasks2_1min and ocr_result values."));
+  assert.equal(result, "Check redo_completed_tasks2_1min and ocr_result values.");
+});
+
 test("renderMarkdown keeps bullet markers", () => {
   const result = stripAnsi(renderMarkdown("- item one\n- item two"));
   assert.equal(result.includes("- item one"), true);

src/ui/components/MessageView/markdown.ts

@@ -396,10 +396,31 @@ function renderInlineLine(line: string): string {
 
 function renderInlineSpans(text: string): string {
   if (!text) return text;
+
+  const parts: string[] = [];
+  const codeRe = /`([^`]+)`/g;
+  let lastIndex = 0;
+  let match: RegExpExecArray | null;
+
+  while ((match = codeRe.exec(text)) !== null) {
+    if (match.index > lastIndex) {
+      parts.push(renderEmphasisSpans(text.slice(lastIndex, match.index)));
+    }
+    parts.push(chalk.cyan(match[1] ?? ""));
+    lastIndex = match.index + match[0].length;
+  }
+
+  if (lastIndex < text.length) {
+    parts.push(renderEmphasisSpans(text.slice(lastIndex)));
+  }
+
+  return parts.join("");
+}
+
+function renderEmphasisSpans(text: string): string {
   let result = text;
-  result = result.replace(/`([^`]+)`/g, (_, inner) => chalk.cyan(inner));
   result = result.replace(/\*\*([^*]+)\*\*/g, (_, inner) => chalk.bold(inner));
   result = result.replace(/(?<!\*)\*([^*]+)\*(?!\*)/g, (_, inner) => chalk.italic(inner));
-  result = result.replace(/_([^_\n]+)_/g, (_, inner) => chalk.italic(inner));
+  result = result.replace(/(?<![\p{L}\p{N}_])_([^_\n]+)_(?![\p{L}\p{N}_])/gu, (_, inner) => chalk.italic(inner));
   return result;
 }