feat: joinRelativeURL (#220)

README.md

@@ -255,6 +255,16 @@ isSamePath("/foo", "/foo/"); // true
 
 Checks if the input protocol is any of the dangerous `blob:`, `data:`, `javascript`: or `vbscript:` protocols.
 
+### `joinRelativeURL()`
+
+Joins multiple URL segments into a single URL and also handles relative paths with `./` and `../`.
+
+**Example:**
+
+```js
+joinRelativeURL("/a", "../b", "./c"); // "/b/c"
+```
+
 ### `joinURL(base)`
 
 Joins multiple URL segments into a single URL.

src/utils.ts

@@ -13,6 +13,7 @@ const PROTOCOL_REGEX = /^[\s\w\0+.-]{2,}:([/\\]{2})?/;
 const PROTOCOL_RELATIVE_REGEX = /^([/\\]\s*){2,}[^/\\]/;
 const PROTOCOL_SCRIPT_RE = /^[\s\0]*(blob|data|javascript|vbscript):$/i;
 const TRAILING_SLASH_RE = /\/$|\/\?|\/#/;
+const JOIN_LEADING_SLASH_RE = /^\.?\//;
 
 /**
  * Check if a path starts with `./` or `../`.
@@ -317,7 +318,34 @@ export function isNonEmptyURL(url: string) {
  *
  * @group utils
  */
-export function joinURL(..._input: string[]): string {
+export function joinURL(base: string, ...input: string[]): string {
+  let url = base || "";
+
+  for (const segment of input.filter((url) => isNonEmptyURL(url))) {
+    if (url) {
+      // TODO: Handle .. when joining
+      const _segment = segment.replace(JOIN_LEADING_SLASH_RE, "");
+      url = withTrailingSlash(url) + _segment;
+    } else {
+      url = segment;
+    }
+  }
+
+  return url;
+}
+
+/**
+ * Joins multiple URL segments into a single URL and also handles relative paths with `./` and `../`.
+ *
+ * @example
+ *
+ * ```js
+ * joinRelativeURL("/a", "../b", "./c"); // "/b/c"
+ * ```
+ *
+ * @group utils
+ */
+export function joinRelativeURL(..._input: string[]): string {
   const input = _input.filter(Boolean);
 
   const segments: string[] = [];

test/base.test.ts

@@ -5,7 +5,7 @@ describe("withBase", () => {
   const tests = [
     { base: "/", input: "/", out: "/" },
     { base: "/foo", input: "", out: "/foo" },
-    { base: "/foo/", input: "/", out: "/foo/" },
+    { base: "/foo/", input: "/", out: "/foo" },
     { base: "/foo", input: "/bar", out: "/foo/bar" },
     { base: "/base/", input: "/base", out: "/base" },
     { base: "/base", input: "/base/", out: "/base/" },

test/join.test.ts

@@ -1,23 +1,34 @@
 import { describe, expect, test } from "vitest";
-import { joinURL } from "../src";
+import { joinURL, joinRelativeURL } from "../src";
+
+const joinURLTests = [
+  { input: [], out: "" },
+  { input: ["/"], out: "/" },
+  { input: [undefined, "./"], out: "./" },
+  { input: ["./", "a"], out: "./a" },
+  { input: ["./a", "./b"], out: "./a/b" },
+  { input: ["/a"], out: "/a" },
+  { input: ["a", "b"], out: "a/b" },
+  { input: ["/", "/b"], out: "/b" },
+  { input: ["a", "b/", "c"], out: "a/b/c" },
+  { input: ["a", "b/", "/c"], out: "a/b/c" },
+  { input: ["/", "./"], out: "/" },
+  { input: ["/", "./foo"], out: "/foo" },
+  { input: ["/", "./foo/"], out: "/foo/" },
+  { input: ["/", "./foo", "bar"], out: "/foo/bar" },
+] as const;
 
 describe("joinURL", () => {
-  const tests = [
-    { input: [], out: "" },
-    { input: ["/"], out: "/" },
-    { input: [undefined, "./"], out: "./" },
-    { input: ["./", "a"], out: "./a" },
-    { input: ["./a", "./b"], out: "./a/b" },
-    { input: ["/a"], out: "/a" },
-    { input: ["a", "b"], out: "a/b" },
-    { input: ["/", "/b"], out: "/b" },
-    { input: ["a", "b/", "c"], out: "a/b/c" },
-    { input: ["a", "b/", "/c"], out: "a/b/c" },
-    { input: ["/", "./"], out: "/" },
-    { input: ["/", "./foo"], out: "/foo" },
-    { input: ["/", "./foo/"], out: "/foo/" },
-    { input: ["/", "./foo", "bar"], out: "/foo/bar" },
+  for (const t of joinURLTests) {
+    test(`joinURL(${t.input.map((i) => JSON.stringify(i)).join(", ")}) === ${JSON.stringify(t.out)}`, () => {
+      expect(joinURL(...(t.input as any[]))).toBe(t.out);
+    });
+  }
+});
 
+describe("joinRelativeURL", () => {
+  const relativeTests = [
+    ...joinURLTests,
     // Relative with ../
     { input: ["/a", "../b"], out: "/b" },
     { input: ["/a/b/c", "../../d"], out: "/a/d" },
@@ -33,9 +44,9 @@ describe("joinURL", () => {
     { input: ["../a/", "../b"], out: "b" },
   ];
 
-  for (const t of tests) {
-    test(`joinURL(${t.input.map((i) => JSON.stringify(i)).join(", ")}) === ${JSON.stringify(t.out)}`, () => {
-      expect(joinURL(...(t.input as string[]))).toBe(t.out);
+  for (const t of relativeTests) {
+    test(`joinRelativeURL(${t.input.map((i) => JSON.stringify(i)).join(", ")}) === ${JSON.stringify(t.out)}`, () => {
+      expect(joinRelativeURL(...(t.input as string[]))).toBe(t.out);
     });
   }
 });