claude: Consolidate isExternalPath helper to src/core/url.ts

Move the duplicated isExternalPath function to a single location in
src/core/url.ts and update all call sites to import from there.

This addresses feedback from @cderv on PR #13901.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gordonwoodhull

src/core/brand/brand.ts

@@ -32,6 +32,7 @@ import { InternalError } from "../lib/error.ts";
 import { dirname, join, relative, resolve } from "../../deno_ral/path.ts";
 import { warnOnce } from "../log.ts";
 import { isCssColorName } from "../css/color-names.ts";
+import { isExternalPath } from "../url.ts";
 import {
   LogoLightDarkSpecifierPathOptional,
   LogoOptionsPathOptional,
@@ -272,10 +273,6 @@ export class Brand {
   }
 }
 
-function isExternalPath(path: string) {
-  return /^\w+:/.test(path);
-}
-
 export type LightDarkBrand = {
   light?: Brand;
   dark?: Brand;

src/core/sass/brand.ts

@@ -26,6 +26,7 @@ import { Brand } from "../brand/brand.ts";
 import { darkModeDefault } from "../../format/html/format-html-info.ts";
 import { kBrandMode } from "../../config/constants.ts";
 import { join, relative } from "../../deno_ral/path.ts";
+import { isExternalPath } from "../url.ts";
 
 const defaultColorNameMap: Record<string, string> = {
   "link-color": "link",
@@ -150,8 +151,6 @@ const googleFontImportString = (description: BrandFontGoogle) => {
   }:${styleString}wght@${weights}&display=${display}');`;
 };
 
-const isExternalPath = (path: string) => /^\w+:/.test(path);
-
 const fileFontImportString = (brand: Brand, description: BrandFontFile) => {
   const pathPrefix = relative(brand.projectDir, brand.brandDir);
   const parts = [];

src/core/url.ts

@@ -1,16 +1,19 @@
 /*
-* url.ts
-*
-* Copyright (C) 2020-2022 Posit Software, PBC
-*
-*/
+ * url.ts
+ *
+ * Copyright (C) 2020-2022 Posit Software, PBC
+ */
 
 import { ensureTrailingSlash, pathWithForwardSlashes } from "./path.ts";
 
 export function isHttpUrl(url: string) {
   return /^https?:/i.test(url);
 }
 
+export function isExternalPath(path: string) {
+  return /^\w+:/.test(path);
+}
+
 export function joinUrl(baseUrl: string, path: string) {
   const baseHasSlash = baseUrl.endsWith("/");
 

src/project/types/website/website-navigation.ts

@@ -12,6 +12,7 @@ import { Document, Element } from "../../../core/deno-dom.ts";
 
 import { pathWithForwardSlashes, safeExistsSync } from "../../../core/path.ts";
 import { resourcePath } from "../../../core/resources.ts";
+import { isExternalPath } from "../../../core/url.ts";
 import { renderEjs } from "../../../core/ejs.ts";
 import { warnOnce } from "../../../core/log.ts";
 import { asHtmlId } from "../../../core/html.ts";
@@ -1540,10 +1541,6 @@ function navigationDependency(resource: string) {
   };
 }
 
-function isExternalPath(path: string) {
-  return /^\w+:/.test(path);
-}
-
 function resolveNavReferences(
   collection: unknown | Array<unknown> | Record<string, unknown>,
 ) {

src/project/types/website/website-utils.ts

@@ -8,6 +8,7 @@ import { Document, Element } from "../../../core/deno-dom.ts";
 import { getDecodedAttribute } from "../../../core/html.ts";
 import { resolveInputTarget } from "../../project-index.ts";
 import { pathWithForwardSlashes, safeExistsSync } from "../../../core/path.ts";
+import { isExternalPath } from "../../../core/url.ts";
 import { projectOffset, projectOutputDir } from "../../project-shared.ts";
 import { engineValidExtensions } from "../../../execute/engine.ts";
 import { ProjectContext } from "../../types.ts";
@@ -119,7 +120,3 @@ export async function resolveProjectInputLinks(
     }
   }
 }
-
-function isExternalPath(path: string) {
-  return /^\w+:/.test(path);
-}