In href(), remove need for slice and ignore trailing slashes from input

Author: ngbrown

packages/react-router/lib/href.ts

@@ -27,23 +27,24 @@ export function href<Path extends keyof Args>(
   ...args: Args[Path]
 ): string {
   let params = args[0];
-  let result = path.replace(
-    /\/:([\w-]+)(\?)?/g, // same regex as in .\router\utils.ts: compilePath().
-    (_: string, param: string, isOptional) => {
-      const value = params ? params[param] : undefined;
-      if (isOptional == null && value == null) {
-        throw new Error(
-          `Path '${path}' requires param '${param}' but it was not provided`,
-        );
-      }
-      return value == null ? "" : "/" + value;
-    },
-  );
+  let result = path
+    .replace(/\/*\*?$/, "") // Ignore trailing / and /*, we'll handle it below
+    .replace(
+      /\/:([\w-]+)(\?)?/g, // same regex as in .\router\utils.ts: compilePath().
+      (_: string, param: string, isOptional) => {
+        const value = params ? params[param] : undefined;
+        if (isOptional == null && value == null) {
+          throw new Error(
+            `Path '${path}' requires param '${param}' but it was not provided`,
+          );
+        }
+        return value == null ? "" : "/" + value;
+      },
+    );
 
-  if (result.endsWith("*")) {
+  if (path.endsWith("*")) {
     // treat trailing splat the same way as compilePath, and force it to be as if it were `/*`.
     // `react-router typegen` will not generate the params for a malformed splat, causing a type error, but we can still do the correct thing here.
-    result = result.slice(0, result.endsWith("/*") ? -2 : -1);
     if (params && params["*"] != null) {
       result += "/" + params["*"];
     }