refactor: add utility to remove base path

3w36zj6 · 3w36zj6 · commit f783b249eeb2 · 2025-08-20T06:39:20.000+09:00
diff --git a/website/src/components/templates/BaseTemplate.tsx b/website/src/components/templates/BaseTemplate.tsx
@@ -2,7 +2,7 @@ import { html } from "hono/html";
 import type { FC, PropsWithChildren } from "hono/jsx";
 import { basePath, originUrl, typstOfficialDocsUrl } from "../../metadata";
 import type { Page } from "../../types/model";
-import { joinPath } from "../../utils/path";
+import { joinPath, removeBasePath } from "../../utils/path";
 import { getTranslationStatus } from "../../utils/translationStatus";
 import {
 	CaretRightCircleIcon,
@@ -46,7 +46,10 @@ export const BaseTemplate: FC<BaseTemplateProps> = ({
 	const translationStatus = getTranslationStatus(route);
 	const absoluteRouteUrl = new URL(route, originUrl).toString();
 	const faviconUrl = new URL(`${basePath}/favicon.png`, originUrl).toString();
-	const typstOfficialRouteUrl = joinPath(typstOfficialDocsUrl, route.slice(basePath.length - (basePath.endsWith("/") ? 1 : 0)));
+	const typstOfficialRouteUrl = joinPath(
+		typstOfficialDocsUrl,
+		removeBasePath(basePath, route),
+	);
 	return (
 		<html lang="ja" class="scroll-pt-24">
 			<head>
diff --git a/website/src/index.tsx b/website/src/index.tsx
@@ -13,6 +13,7 @@ import { basePath } from "./metadata";
 import type { Body, Page } from "./types/model";
 import { flattenDocs } from "./utils/flattenDocs";
 import { isPageOfKind } from "./utils/isPageOfKind";
+import { removeBasePath } from "./utils/path";
 import { registerRoutes } from "./utils/translationStatus";
 
 // typst-docsが生成したドキュメント
@@ -55,7 +56,7 @@ The 'basePath' must match the 'base' value used in typst-docs.
 Please ensure both this site and typst-docs are configured with the same base path.`,
 		);
 	}
-	route = route.slice(basePath.length - (basePath.endsWith("/") ? 1 : 0));
+	route = removeBasePath(basePath, route);
 	app.get(route, (c) => {
 		if (isPageOfKind(page, "html")) {
 			return c.html(<HtmlTemplate page={page} {...commonProps} />);
diff --git a/website/src/utils/path.test.ts b/website/src/utils/path.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { applyBasePath, joinPath } from "./path";
+import { applyBasePath, joinPath, removeBasePath } from "./path";
 
 describe("joinPath", () => {
 	it("should join base and path with single slash", () => {
@@ -45,3 +45,24 @@ describe("applyBasePath", () => {
 		expect(applyBasePath("", "/foo")).toBe("/foo");
 	});
 });
+
+describe("removeBasePath", () => {
+	it("should remove basePath with trailing slash", () => {
+		expect(removeBasePath("/docs/", "/docs/foo/bar")).toBe("/foo/bar");
+		expect(removeBasePath("/base/", "/base/foo")).toBe("/foo");
+	});
+	it("should remove basePath without trailing slash", () => {
+		expect(removeBasePath("/docs", "/docs/foo/bar")).toBe("/foo/bar");
+		expect(removeBasePath("/base", "/base/foo")).toBe("/foo");
+	});
+	it("should return route unchanged if it does not start with basePath", () => {
+		expect(removeBasePath("/docs", "/other/foo")).toBe("/other/foo");
+		expect(removeBasePath("/base", "/docs/foo")).toBe("/docs/foo");
+	});
+	it("should handle root basePath", () => {
+		expect(removeBasePath("/", "/foo/bar")).toBe("/foo/bar");
+	});
+	it("should handle empty basePath", () => {
+		expect(removeBasePath("", "/foo/bar")).toBe("/foo/bar");
+	});
+});
diff --git a/website/src/utils/path.ts b/website/src/utils/path.ts
@@ -46,3 +46,22 @@ export const applyBasePath = (basePath: string, path: string): string => {
 	const isRelative = !path.startsWith("/");
 	return isRelative ? path : joinPath(basePath, path);
 };
+
+/**
+ * Removes the basePath prefix from a route string.
+ *
+ * @param basePath - The base path to remove.
+ * @param route - The route string to process.
+ * @returns The route string with basePath removed from the start.
+ *
+ * @example
+ * ```ts
+ * removeBasePath("/docs/", "/docs/foo/bar") -> "/foo/bar"
+ * removeBasePath("/docs", "/docs/foo/bar") -> "/foo/bar"
+ * ```
+ */
+export const removeBasePath = (basePath: string, route: string): string => {
+	if (!route.startsWith(basePath)) return route;
+	const offset = basePath.length - (basePath.endsWith("/") ? 1 : 0);
+	return route.slice(offset);
+};
