MP path based static content should use index.html (4.x)

etc/copyright-exclude.txt

@@ -24,7 +24,6 @@
 .MD
 .p12
 .txt
-.sql
 jaxb.index
 /MANIFEST.MF
 /README
@@ -35,6 +34,7 @@ jaxb.index
 .p12
 .bin
 .vm
+.sql
 src/main/proto/
 src/test/resources/keystore/
 etc/javadoc/
@@ -55,3 +55,5 @@ target/
 META-INF/services/
 persistence_3_0.xjb
 persistence_3_0.xsd
+# excluded as this is a test file and we need to validate its content
+src/test/resources/static/classpath/index.html

microprofile/server/src/main/java/io/helidon/microprofile/server/ServerCdiExtension.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2021 Oracle and/or its affiliates.
+ * Copyright (c) 2018, 2022 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -288,9 +288,10 @@ private void registerPathStaticContent(Config config) {
         StaticContentSupport.FileSystemBuilder pBuilder = StaticContentSupport.builder(config.get("location")
                                                                                                .as(Path.class)
                                                                                                .get());
-        config.get("welcome")
+        pBuilder.welcomeFileName(config.get("welcome")
                 .asString()
-                .ifPresent(pBuilder::welcomeFileName);
+                .orElse("index.html"));
+
         StaticContentSupport staticContent = pBuilder.build();
 
         if (context.exists()) {

tests/integration/mp-gh-4654/pom.xml

@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2022 Oracle and/or its affiliates.
+
+    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
+
+        http://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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>io.helidon.tests.integration</groupId>
+        <artifactId>helidon-tests-integration</artifactId>
+        <version>4.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>helidon-tests-integration-mp-gh-4654</artifactId>
+    <name>Helidon Tests Integration MP GH 4654</name>
+    <description>Reproducer for Github issue #4654 - static content default index</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.helidon.microprofile.server</groupId>
+            <artifactId>helidon-microprofile-server</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.helidon.webserver</groupId>
+            <artifactId>helidon-webserver-test-support</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-all</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

tests/integration/mp-gh-4654/src/test/java/io/helidon/tests/integration/gh4654/Gh4654StaticContentTest.java

@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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
+ *
+ *     http://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 io.helidon.tests.integration.gh4654;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+
+import io.helidon.config.mp.MpConfigSources;
+import io.helidon.microprofile.server.Server;
+import io.helidon.webserver.testsupport.TemporaryFolder;
+import io.helidon.webserver.testsupport.TemporaryFolderExtension;
+
+import jakarta.ws.rs.client.Client;
+import jakarta.ws.rs.client.ClientBuilder;
+import jakarta.ws.rs.client.WebTarget;
+import jakarta.ws.rs.core.Response;
+import org.eclipse.microprofile.config.Config;
+import org.eclipse.microprofile.config.spi.ConfigProviderResolver;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+@ExtendWith(TemporaryFolderExtension.class)
+class Gh4654StaticContentTest {
+    private static Client client;
+    private TemporaryFolder folder;
+    private Server server;
+    private WebTarget target;
+
+    @BeforeAll
+    static void setupAll() {
+        client = ClientBuilder.newClient();
+    }
+
+    @AfterAll
+    static void cleanupAll() {
+        client.close();
+        client = null;
+    }
+
+    @BeforeEach
+    void setup() throws IOException {
+        // cannot use @HelidonTest, as the tmp folder extension requires to be run beforeEach
+
+        // root
+        Path root = folder.root().toPath();
+        Files.writeString(root.resolve("index.html"), "Root Index HTML");
+        Files.writeString(root.resolve("foo.txt"), "Foo TXT");
+        // css
+        Path cssDir = folder.newFolder("css").toPath();
+        Files.writeString(cssDir.resolve("a.css"), "A CSS");
+        // bar
+        Path other = folder.newFolder("other").toPath();
+        Files.writeString(other.resolve("index.html"), "Other Index");
+
+        ConfigProviderResolver cpr = ConfigProviderResolver.instance();
+        Config config = cpr.getBuilder()
+                .withSources(MpConfigSources.create(Map.of(
+                        "server.host", "localhost",
+                        "server.port", "0",
+                        "server.static.path.location", folder.root().getAbsolutePath(),
+                        "server.static.path.context", "/static",
+                        "server.static.classpath.location", "/static",
+                        "server.static.classpath.context", "/static"
+                )))
+                .build();
+        cpr.registerConfig(config, null);
+
+        server = Server.create()
+                .start();
+
+        target = client.target("http://localhost:" + server.port() + "/static");
+
+    }
+
+    @AfterEach
+    void cleanup() {
+        server.stop();
+        target = null;
+    }
+
+    @ParameterizedTest(name = "\"{0}\" - {2}")
+    @CsvSource({
+            "/,Root Index HTML,path should serve index.html",
+            "/index.html,Root Index HTML,path should serve index.html",
+            "/foo.txt,Foo TXT,path should serve foo.txt",
+            "/css/a.css,A CSS,path should serve css/a.css",
+            "/other,Other Index,path should serve other/index.html",
+            "/other/index.html,Other Index,path should serve other/index.html",
+            "/classpath,classpath index,classpath should serve index.html",
+            "/classpath/index.html,classpath index,classpath should serve index.html"
+    })
+    void testExists(String path, String expectedContent, String name) {
+        Response response = target.path(path)
+                .request()
+                .get();
+
+        assertThat(response.getStatus(), is(200));
+        assertThat(response.readEntity(String.class), is(expectedContent));
+    }
+
+    @ParameterizedTest(name = "{0}")
+    @CsvSource({
+            "/not-there.txt",
+            "/css/not-there.txt",
+            "/classpath/not-there.txt"
+    })
+    void test404(String path) {
+        Response response = target.path(path)
+                .request()
+                .get();
+
+        assertThat(response.getStatus(), is(404));
+    }
+}

tests/integration/mp-gh-4654/src/test/resources/static/classpath/index.html

@@ -0,0 +1 @@
+classpath index

tests/integration/pom.xml

@@ -49,6 +49,7 @@
         <module>mp-gh-3246</module>
         <module>mp-gh-3974</module>
         <module>mp-gh-4123</module>
+        <module>mp-gh-4654</module>
         <module>kafka</module>
         <module>jms</module>
         <module>config</module>

webserver/static-content/src/test/java/io/helidon/webserver/staticcontent/FileSystemContentHandlerTest.java

@@ -43,23 +43,23 @@
  * Tests {@link io.helidon.webserver.staticcontent.FileSystemContentHandler}.
  */
 @ExtendWith(TemporaryFolderExtension.class)
-public class FileSystemContentHandlerTest {
+class FileSystemContentHandlerTest {
 
     private TemporaryFolder folder;
 
     @BeforeEach
     public void createContent() throws IOException {
         // root
         Path root = folder.root().toPath();
-        Files.write(root.resolve("index.html"), "Index HTML".getBytes(StandardCharsets.UTF_8));
-        Files.write(root.resolve("foo.txt"), "Foo TXT".getBytes(StandardCharsets.UTF_8));
+        Files.writeString(root.resolve("index.html"), "Index HTML");
+        Files.writeString(root.resolve("foo.txt"), "Foo TXT");
         // css
         Path cssDir = folder.newFolder("css").toPath();
-        Files.write(cssDir.resolve("a.css"), "A CSS".getBytes(StandardCharsets.UTF_8));
-        Files.write(cssDir.resolve("b.css"), "B CSS".getBytes(StandardCharsets.UTF_8));
+        Files.writeString(cssDir.resolve("a.css"), "A CSS");
+        Files.writeString(cssDir.resolve("b.css"), "B CSS");
         // bar
         Path other = folder.newFolder("other").toPath();
-        Files.write(other.resolve("index.html"), "Index HTML".getBytes(StandardCharsets.UTF_8));
+        Files.writeString(other.resolve("index.html"), "Index HTML");
     }
 
     static String responseToString(TestResponse response)
@@ -71,8 +71,7 @@ static String responseToString(TestResponse response)
     }
 
     @Test
-    public void serveFile() throws Exception {
-        try {
+    void serveFile() throws Exception {
         Routing routing = Routing.builder()
                                  .register("/some", StaticContentSupport.create(folder.root().toPath()))
                                  .build();
@@ -105,13 +104,10 @@ public void serveFile() throws Exception {
                 .path("/some/css/")
                 .get();
         assertThat(response.status(), is(Http.Status.NOT_FOUND_404));
-        } catch(Throwable ex){
-            ex.printStackTrace();
-        }
     }
 
     @Test
-    public void serveIndex() throws Exception {
+    void serveIndex() throws Exception {
         Routing routing = Routing.builder()
                 .register(StaticContentSupport.builder(folder.root().toPath())
                                               .welcomeFileName("index.html")