util: respect nested formats in styleText

himself65 · ljharb · aduh95 · commit 075d1968db8b · 2025-07-26T01:32:04.000+02:00
Co-authored-by: Jordan Harband <ljharb@gmail.com> PR-URL: #59098 Fixes: #59035 Reviewed-By: Jordan Harband <ljharb@gmail.com> Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com> Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
diff --git a/lib/util.js b/lib/util.js
@@ -25,6 +25,7 @@ const {
   ArrayIsArray,
   ArrayPrototypePop,
   ArrayPrototypePush,
+  ArrayPrototypeReduce,
   Error,
   ErrorCaptureStackTrace,
   FunctionPrototypeBind,
@@ -36,6 +37,8 @@ const {
   ObjectSetPrototypeOf,
   ObjectValues,
   ReflectApply,
+  RegExp,
+  RegExpPrototypeSymbolReplace,
   StringPrototypeToWellFormed,
 } = primordials;
 
@@ -137,8 +140,7 @@ function styleText(format, text, { validateStream = true, stream = process.stdou
   // If the format is not an array, convert it to an array
   const formatArray = ArrayIsArray(format) ? format : [format];
 
-  let left = '';
-  let right = '';
+  const codes = [];
   for (const key of formatArray) {
     if (key === 'none') continue;
     const formatCodes = inspect.colors[key];
@@ -147,11 +149,56 @@ function styleText(format, text, { validateStream = true, stream = process.stdou
       validateOneOf(key, 'format', ObjectKeys(inspect.colors));
     }
     if (skipColorize) continue;
-    left += escapeStyleCode(formatCodes[0]);
-    right = `${escapeStyleCode(formatCodes[1])}${right}`;
+    ArrayPrototypePush(codes, formatCodes);
   }
 
-  return skipColorize ? text : `${left}${text}${right}`;
+  if (skipColorize) {
+    return text;
+  }
+
+  // Build opening codes
+  let openCodes = '';
+  for (let i = 0; i < codes.length; i++) {
+    openCodes += escapeStyleCode(codes[i][0]);
+  }
+
+  // Process the text to handle nested styles
+  let processedText;
+  if (codes.length > 0) {
+    processedText = ArrayPrototypeReduce(
+      codes,
+      (text, code) => RegExpPrototypeSymbolReplace(
+        // Find the reset code
+        new RegExp(`\\u001b\\[${code[1]}m`, 'g'),
+        text,
+        (match, offset) => {
+          // Check if there's more content after this reset
+          if (offset + match.length < text.length) {
+            if (
+              code[0] === inspect.colors.dim[0] ||
+              code[0] === inspect.colors.bold[0]
+            ) {
+              // Dim and bold are not mutually exclusive, so we need to reapply
+              return `${match}${escapeStyleCode(code[0])}`;
+            }
+            return `${escapeStyleCode(code[0])}`;
+          }
+          return match;
+        },
+      ),
+      text,
+    );
+  } else {
+    processedText = text;
+  }
+
+  // Build closing codes in reverse order
+  let closeCodes = '';
+  for (let i = codes.length - 1; i >= 0; i--) {
+    closeCodes += escapeStyleCode(codes[i][1]);
+  }
+
+  return `${openCodes}${processedText}${closeCodes}`;
 }
 
 /**
diff --git a/test/parallel/test-util-styletext.js b/test/parallel/test-util-styletext.js
@@ -46,6 +46,83 @@ assert.strictEqual(
   '\u001b[1m\u001b[31mtest\u001b[39m\u001b[22m',
 );
 
+assert.strictEqual(
+  util.styleText('red',
+                 'A' + util.styleText('blue', 'B', { validateStream: false }) + 'C',
+                 { validateStream: false }),
+  '\u001b[31mA\u001b[34mB\u001b[31mC\u001b[39m'
+);
+
+assert.strictEqual(
+  util.styleText('red',
+                 'red' +
+    util.styleText('blue', 'blue', { validateStream: false }) +
+    'red' +
+    util.styleText('blue', 'blue', { validateStream: false }) +
+    'red',
+                 { validateStream: false }
+  ),
+  '\x1B[31mred\x1B[34mblue\x1B[31mred\x1B[34mblue\x1B[31mred\x1B[39m'
+);
+
+assert.strictEqual(
+  util.styleText('red',
+                 'red' +
+    util.styleText('blue', 'blue', { validateStream: false }) +
+    'red' +
+    util.styleText('red', 'red', { validateStream: false }) +
+    'red' +
+    util.styleText('blue', 'blue', { validateStream: false }),
+                 { validateStream: false }
+  ),
+  '\x1b[31mred\x1b[34mblue\x1b[31mred\x1b[31mred\x1b[31mred\x1b[34mblue\x1b[39m\x1b[39m'
+);
+
+assert.strictEqual(
+  util.styleText('red',
+                 'A' + util.styleText(['bgRed', 'blue'], 'B', { validateStream: false }) +
+    'C', { validateStream: false }),
+  '\x1B[31mA\x1B[41m\x1B[34mB\x1B[31m\x1B[49mC\x1B[39m'
+);
+
+assert.strictEqual(
+  util.styleText('dim',
+                 'dim' +
+    util.styleText('bold', 'bold', { validateStream: false }) +
+  'dim', { validateStream: false }),
+  '\x1B[2mdim\x1B[1mbold\x1B[22m\x1B[2mdim\x1B[22m'
+);
+
+assert.strictEqual(
+  util.styleText('blue',
+                 'blue' +
+    util.styleText('red',
+                   'red' +
+      util.styleText('green', 'green', { validateStream: false }) +
+      'red', { validateStream: false }) +
+    'blue', { validateStream: false }),
+  '\x1B[34mblue\x1B[31mred\x1B[32mgreen\x1B[31mred\x1B[34mblue\x1B[39m'
+);
+
+assert.strictEqual(
+  util.styleText(
+    'red',
+    'red' +
+    util.styleText(
+      'blue',
+      'blue' + util.styleText('red', 'red', {
+        validateStream: false,
+      }) + 'blue',
+      {
+        validateStream: false,
+      }
+    ) + 'red', {
+      validateStream: false,
+    }
+  ),
+  '\x1b[31mred\x1b[34mblue\x1b[31mred\x1b[34mblue\x1b[31mred\x1b[39m'
+);
+
 assert.strictEqual(
   util.styleText(['bold', 'red'], 'test', { validateStream: false }),
   util.styleText(
