feat: add path utility

Author: 3w36zj6

website/src/utils/path.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, it } from "vitest";
+import { applyBasePath, joinPath } from "./path";
+
+describe("joinPath", () => {
+	it("should join base and path with single slash", () => {
+		expect(joinPath("/base/", "/foo")).toBe("/base/foo");
+		expect(joinPath("/base", "foo")).toBe("/base/foo");
+		expect(joinPath("/base", "/foo/bar")).toBe("/base/foo/bar");
+		expect(joinPath("/foo/bar/", "/baz/qux")).toBe("/foo/bar/baz/qux");
+		expect(joinPath("/foo/bar", "baz/qux")).toBe("/foo/bar/baz/qux");
+	});
+
+	it("should handle root base path correctly", () => {
+		expect(joinPath("/", "/foo")).toBe("/foo");
+		expect(joinPath("/", "foo")).toBe("/foo");
+	});
+
+	it("should handle empty path", () => {
+		expect(joinPath("/base", "")).toBe("/base/");
+		expect(joinPath("/base/", "")).toBe("/base/");
+	});
+
+	it("should handle empty base", () => {
+		expect(joinPath("", "/foo")).toBe("/foo");
+		expect(joinPath("", "foo")).toBe("/foo");
+	});
+});
+
+describe("applyBasePath", () => {
+	it("should apply basePath to absolute path", () => {
+		expect(applyBasePath("/base", "/foo")).toBe("/base/foo");
+		expect(applyBasePath("/foo", "/bar/baz")).toBe("/foo/bar/baz");
+	});
+
+	it("should not apply basePath to relative path", () => {
+		expect(applyBasePath("/base", "./index.html")).toBe("./index.html");
+		expect(applyBasePath("/foo/bar", "baz/qux")).toBe("baz/qux");
+	});
+
+	it("should handle root basePath", () => {
+		expect(applyBasePath("/", "/foo")).toBe("/foo");
+	});
+
+	it("should handle empty basePath", () => {
+		expect(applyBasePath("", "/foo")).toBe("/foo");
+	});
+});

website/src/utils/path.ts

@@ -0,0 +1,48 @@
+/**
+ * Joins two paths by resolving any slash collisions between them.
+ *
+ * @param basePath - The base path to join.
+ * @param path - The path to append to the basePath.
+ * @returns The joined path with redundant slashes resolved.
+ *
+ * @example
+ * ```ts
+ * joinPath("/base/", "/foo") -> "/base/foo"
+ * joinPath("/base", "foo") -> "/base/foo"
+ * joinPath("/base", "/foo/bar") -> "/base/foo/bar"
+ * joinPath("/foo/bar/", "/baz/qux") -> "/foo/bar/baz/qux"
+ * joinPath("/foo/bar", "baz/qux") -> "/foo/bar/baz/qux"
+ * ```
+ */
+export const joinPath = (basePath: string, path: string): string => {
+	// Remove trailing slash from base.
+	const baseClean = basePath !== "/" ? basePath.replace(/\/+$/, "") : basePath;
+	// Remove leading slash from path.
+	const pathClean = path.replace(/^\/+/, "");
+	// Special case: if base is '/', avoid double slash
+	if (baseClean === "/") {
+		return `/${pathClean}`;
+	}
+	return `${baseClean}/${pathClean}`;
+};
+
+/**
+ * Applies a base path to internal non-relative URLs (starting with `/`).
+ * If the path is relative, it is returned as-is.
+ *
+ * @param basePath - The base path to apply.
+ * @param path - The original path to modify.
+ * @returns The modified path with the basePath applied if it was an absolute path.
+ *
+ * @example
+ * ```ts
+ * applyBasePath("/base", "/foo") -> "/base/foo"
+ * applyBasePath("/base", "./index.html") -> "./index.html"
+ * applyBasePath("/foo", "/bar/baz") -> "/foo/bar/baz"
+ * applyBasePath("/foo/bar", "baz/qux") -> "baz/qux"
+ * ```
+ */
+export const applyBasePath = (basePath: string, path: string): string => {
+	const isRelative = !path.startsWith("/");
+	return isRelative ? path : joinPath(basePath, path);
+};