webauthn: use DefaultResourcesFilter#webauthn

- Unconditionally use the DefaultResourcesFilter, because the javascript file is required by the
  DefaultWebAythnPageGeneratingFilter, which is always registered.

config/src/test/java/org/springframework/security/config/annotation/web/configurers/WebAuthnConfigurerTests.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.test.SpringTestContext;
+import org.springframework.security.config.test.SpringTestContextExtension;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.provisioning.InMemoryUserDetailsManager;
+import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * @author Daniel Garnier-Moiroux
+ */
+@ExtendWith(SpringTestContextExtension.class)
+public class WebAuthnConfigurerTests {
+
+	public final SpringTestContext spring = new SpringTestContext(this);
+
+	@Autowired
+	MockMvc mvc;
+
+	@Test
+	public void javascriptWhenWebauthnConfiguredThenServesJavascript() throws Exception {
+		this.spring.register(DefaultWebauthnConfiguration.class).autowire();
+		this.mvc.perform(get("/login/webauthn.js"))
+			.andExpect(status().isOk())
+			.andExpect(header().string("content-type", "text/javascript;charset=UTF-8"))
+			.andExpect(content().string(containsString("async function authenticate(")));
+	}
+
+	@Configuration
+	@EnableWebSecurity
+	static class DefaultWebauthnConfiguration {
+
+		@Bean
+		UserDetailsService userDetailsService() {
+			return new InMemoryUserDetailsManager();
+		}
+
+		@Bean
+		SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
+			return http.webAuthn(Customizer.withDefaults()).build();
+		}
+
+	}
+
+}