util: respect nested formats in styleText

Author: himself65

lib/util.js

@@ -108,6 +108,9 @@ function escapeStyleCode(code) {
   return `\u001b[${code}m`;
 }
 
+// eslint-disable-next-line no-control-regex
+const endingRegex = /\u001b\[[34]9m/g;
+
 /**
  * @param {string | string[]} format
  * @param {string} text
@@ -134,24 +137,58 @@ function styleText(format, text, { validateStream = true, stream = process.stdou
     skipColorize = !lazyUtilColors().shouldColorize(stream);
   }
 
+  if (skipColorize) {
+    return text;
+  }
+
   // If the format is not an array, convert it to an array
   const formatArray = ArrayIsArray(format) ? format : [format];
 
-  let left = '';
-  let right = '';
+  // Collect the codes we're applying
+  const codes = [];
   for (const key of formatArray) {
     if (key === 'none') continue;
     const formatCodes = inspect.colors[key];
     // If the format is not a valid style, throw an error
     if (formatCodes == null) {
       validateOneOf(key, 'format', ObjectKeys(inspect.colors));
     }
-    if (skipColorize) continue;
-    left += escapeStyleCode(formatCodes[0]);
-    right = `${escapeStyleCode(formatCodes[1])}${right}`;
+
+    codes.push(formatCodes);
+  }
+
+  if (codes.length === 0) {
+    return text;
+  }
+
+  // Build opening codes
+  let openCodes = '';
+  for (const { 0: open } of codes) {
+    openCodes += escapeStyleCode(open);
+  }
+
+  // Process the text to handle nested styles
+  const processedText = text.replace(endingRegex, (match, offset) => {
+    // Check if there's more content after this reset
+    if (offset + match.length < text.length) {
+      for (const { 0: open } of codes) {
+        // Check if this is a foreground color (30-37, 90-97) or Background color (40-47, 100-107)
+        if ((open >= 30 && open <= 37) || (open >= 90 && open <= 97) ||
+            (open >= 40 && open <= 47) || (open >= 100 && open <= 107)) {
+          return escapeStyleCode(open);
+        }
+      }
+    }
+    return match;
+  });
+
+  // Build closing codes in reverse order
+  let closeCodes = '';
+  for (let i = codes.length - 1; i >= 0; i--) {
+    closeCodes += escapeStyleCode(codes[i][1]);
   }
 
-  return skipColorize ? text : `${left}${text}${right}`;
+  return `${openCodes}${processedText}${closeCodes}`;
 }
 
 /**

test/parallel/test-util-styletext.js

@@ -46,6 +46,11 @@ assert.strictEqual(
   '\u001b[1m\u001b[31mtest\u001b[39m\u001b[22m',
 );
 
+assert.strictEqual(
+  util.styleText('red', 'A' + util.styleText('blue', 'B') + 'C'),
+  '\u001b[31mA\u001b[34mB\u001b[31mC\u001b[39m',
+);
+
 assert.strictEqual(
   util.styleText(['bold', 'red'], 'test', { validateStream: false }),
   util.styleText(