refactor: extract splitOutsideParens shared helper

The CLI's comma-splitter for color args and the logger's dot-splitter for
color path segments shared near-identical paren-aware string walking. Extract
the shared logic into lib/utils.ts, parameterized on the delimiter, and wire
up both call sites.

Author: stephanschubert

bin/index.ts

@@ -7,31 +7,9 @@ import { hideBin } from 'yargs/helpers';
 import { assertDeprecated } from '../lib/assert.js';
 import * as defaults from '../lib/defaults.js';
 import { concurrently } from '../lib/index.js';
-import { castArray } from '../lib/utils.js';
+import { castArray, splitOutsideParens } from '../lib/utils.js';
 import { readPackageJson } from './read-package-json.js';
 
-/**
- * Splits a color arguments string on commas, but preserves commas inside parentheses.
- * e.g., "red,rgb(255,255,0),blue" → ["red", "rgb(255,255,0)", "blue"]
- */
-function splitColorArgs(input: string): string[] {
-    const colors: string[] = [];
-    let current = '';
-    let parenDepth = 0;
-    for (const char of input) {
-        if (char === '(') parenDepth++;
-        if (char === ')') parenDepth--;
-        if (char === ',' && parenDepth === 0) {
-            if (current.trim()) colors.push(current.trim());
-            current = '';
-        } else {
-            current += char;
-        }
-    }
-    if (current.trim()) colors.push(current.trim());
-    return colors;
-}
-
 const version = String(readPackageJson().version);
 const epilogue = `For documentation and more examples, visit:\nhttps://github.com/open-cli-tools/concurrently/tree/v${version}/docs`;
 
@@ -278,7 +256,7 @@ concurrently(
         hide: args.hide.split(','),
         group: args.group,
         prefix: args.prefix,
-        prefixColors: splitColorArgs(args.prefixColors),
+        prefixColors: splitOutsideParens(args.prefixColors, ','),
         prefixLength: args.prefixLength,
         padPrefix: args.padPrefix,
         restartDelay:

lib/logger.ts

@@ -4,34 +4,11 @@ import Rx from 'rxjs';
 import { Command, CommandIdentifier } from './command.js';
 import { DateFormatter } from './date-format.js';
 import * as defaults from './defaults.js';
-import { escapeRegExp } from './utils.js';
+import { escapeRegExp, splitOutsideParens } from './utils.js';
 
 const defaultChalk = chalk;
 const noColorChalk = new Chalk({ level: 0 });
 
-/**
- * Parses a color string into segments, preserving function calls as single tokens.
- * e.g., "black.bgHex(#533AFD).dim" → ["black", "bgHex(#533AFD)", "dim"]
- */
-function parseColorSegments(colorString: string): string[] {
-    const segments: string[] = [];
-    let current = '';
-    let parenDepth = 0;
-
-    for (const char of colorString) {
-        if (char === '(') parenDepth++;
-        if (char === ')') parenDepth--;
-        if (char === '.' && parenDepth === 0) {
-            if (current) segments.push(current);
-            current = '';
-        } else {
-            current += char;
-        }
-    }
-    if (current) segments.push(current);
-    return segments;
-}
-
 const HEX_PATTERN = /^#[0-9A-Fa-f]{3,6}$/;
 
 /**
@@ -83,7 +60,7 @@ function applySegment(color: ChalkInstance, segment: string): ChalkInstance | un
  * Returns undefined if any segment is invalid (triggers fallback to default).
  */
 function applyColor(chalkInstance: ChalkInstance, colorString: string): ChalkInstance | undefined {
-    const segments = parseColorSegments(colorString);
+    const segments = splitOutsideParens(colorString, '.');
     if (segments.length === 0) return undefined;
 
     let color: ChalkInstance = chalkInstance;

lib/utils.spec.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest';
 
-import { castArray, escapeRegExp } from './utils.js';
+import { castArray, escapeRegExp, splitOutsideParens } from './utils.js';
 
 describe('#escapeRegExp()', () => {
     it('escapes all RegExp chars', () => {
@@ -37,3 +37,37 @@ describe('#castArray()', () => {
         });
     });
 });
+
+describe('#splitOutsideParens()', () => {
+    it('splits on the given delimiter', () => {
+        expect(splitOutsideParens('red,blue', ',')).toEqual(['red', 'blue']);
+    });
+
+    it('preserves delimiters inside parentheses', () => {
+        expect(splitOutsideParens('red,rgb(255,0,0),blue', ',')).toEqual([
+            'red',
+            'rgb(255,0,0)',
+            'blue',
+        ]);
+    });
+
+    it('splits chalk-style dotted color paths, preserving function calls', () => {
+        expect(splitOutsideParens('black.bgHex(#533AFD).dim', '.')).toEqual([
+            'black',
+            'bgHex(#533AFD)',
+            'dim',
+        ]);
+    });
+
+    it('trims whitespace around each segment', () => {
+        expect(splitOutsideParens('  red ,  blue  ', ',')).toEqual(['red', 'blue']);
+    });
+
+    it('drops empty segments', () => {
+        expect(splitOutsideParens(',,red,,', ',')).toEqual(['red']);
+    });
+
+    it('returns an empty array for an empty input', () => {
+        expect(splitOutsideParens('', ',')).toEqual([]);
+    });
+});

lib/utils.ts

@@ -13,3 +13,31 @@ type CastArrayResult<T> = T extends undefined | null ? never[] : T extends unkno
 export function castArray<T = never[]>(value?: T) {
     return (Array.isArray(value) ? value : value != null ? [value] : []) as CastArrayResult<T>;
 }
+
+/**
+ * Splits a string on `delimiter`, ignoring delimiters inside parentheses.
+ * Trims each segment and discards empty ones.
+ *
+ * Examples:
+ *   splitOutsideParens('red,rgb(255,0,0),blue', ',') → ['red', 'rgb(255,0,0)', 'blue']
+ *   splitOutsideParens('black.bgHex(#533AFD).dim', '.') → ['black', 'bgHex(#533AFD)', 'dim']
+ */
+export function splitOutsideParens(input: string, delimiter: string): string[] {
+    const segments: string[] = [];
+    let current = '';
+    let parenDepth = 0;
+    for (const char of input) {
+        if (char === '(') parenDepth++;
+        else if (char === ')') parenDepth--;
+        if (char === delimiter && parenDepth === 0) {
+            const trimmed = current.trim();
+            if (trimmed) segments.push(trimmed);
+            current = '';
+        } else {
+            current += char;
+        }
+    }
+    const trimmed = current.trim();
+    if (trimmed) segments.push(trimmed);
+    return segments;
+}