perf(compiler): short circuit when no routes exist

Author: pi0

src/compiler.ts

@@ -97,6 +97,10 @@ function compileRouteMatch(
     str += "let s=p.split('/'),l=s.length-1;" + match;
   }
 
+  if (!str) {
+    return opts?.matchAll ? "return [];" : "";
+  }
+
   return `${opts?.matchAll ? `let r=[];` : ""}if(p[p.length-1]==='/')p=p.slice(0,-1)||'/';${str}${opts?.matchAll ? "return r;" : ""}`;
 }
 

test/.snapshot/compiled-all-empty.mjs

@@ -0,0 +1,3 @@
+(m, p) => {
+  return [];
+};

test/.snapshot/compiled-empty.mjs

@@ -0,0 +1 @@
+(m, p) => {};

test/find-all.test.ts

@@ -51,6 +51,17 @@ describe("find-matchAll: basic", () => {
     ).toMatchFileSnapshot(".snapshot/compiled-all.mjs");
   });
 
+  it("snapshot (compiled - empty)", async () => {
+    await expect(
+      await format(
+        compileRouter(createRouter([]), { matchAll: true }).toString(),
+        {
+          parser: "acorn",
+        },
+      ),
+    ).toMatchFileSnapshot(".snapshot/compiled-all-empty.mjs");
+  });
+
   it("matches /foo/bar/baz pattern", () => {
     const matches = _findAllRoutes(router, "GET", "/foo/bar/baz");
     expect(matches).to.toMatchInlineSnapshot(`

test/find.test.ts

@@ -55,6 +55,14 @@ describe("route matching", () => {
     ).toMatchFileSnapshot(".snapshot/compiled-aot.mjs");
   });
 
+  it("snapshot (compiled - empty)", async () => {
+    await expect(
+      await format(compileRouter(createRouter([])).toString(), {
+        parser: "acorn",
+      }),
+    ).toMatchFileSnapshot(".snapshot/compiled-empty.mjs");
+  });
+
   const lookups = [
     {
       name: "findRoute",