feat(path): add isAbsoluteURL function and corresponding tests

quartz/util/path.test.ts

@@ -38,6 +38,17 @@ describe("typeguards", () => {
     assert(!path.isRelativeURL("./abc/def.md"))
   })
 
+  test("isAbsoluteURL", () => {
+    assert(path.isAbsoluteURL("https://example.com"))
+    assert(path.isAbsoluteURL("http://example.com"))
+    assert(path.isAbsoluteURL("ftp://example.com/a/b/c"))
+    assert(path.isAbsoluteURL("http://host/%25"))
+    assert(path.isAbsoluteURL("file://host/twoslashes?more//slashes"))
+
+    assert(!path.isAbsoluteURL("example.com/abc/def"))
+    assert(!path.isAbsoluteURL("abc"))
+  })
+
   test("isFullSlug", () => {
     assert(path.isFullSlug("index"))
     assert(path.isFullSlug("abc/def"))

quartz/util/path.ts

@@ -1,6 +1,8 @@
 import { slug as slugAnchor } from "github-slugger"
 import type { Element as HastElement } from "hast"
 import { clone } from "./clone"
+import { URL } from "url"
+
 // this file must be isomorphic so it can't use node libs (e.g. path)
 
 export const QUARTZ = "quartz"
@@ -15,7 +17,6 @@ export function isFilePath(s: string): s is FilePath {
   return validStart && _hasFileExtension(s)
 }
 
-
 /** Cannot be relative and may not have leading or trailing slashes. It can have `index` as it's last segment. Use this wherever possible is it's the most 'general' interpretation of a slug. */
 export type FullSlug = SlugLike<"full">
 export function isFullSlug(s: string): s is FullSlug {
@@ -43,10 +44,10 @@ export function isRelativeURL(s: string): s is RelativeURL {
 export function isAbsoluteURL(s: string): boolean {
   try {
     new URL(s)
-    return true
   } catch {
     return false
   }
+  return true
 }
 
 export function getFullSlug(window: Window): FullSlug {