java.util.List contains null if query param doesn't specified fix #1806

jooby/src/main/java/io/jooby/internal/MissingValue.java

@@ -12,6 +12,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 
 public class MissingValue implements ValueNode {
@@ -41,6 +42,10 @@ public MissingValue(String name) {
     throw new MissingValueException(name);
   }
 
+  @Nonnull @Override public Map<String, String> toMap() {
+    return Collections.emptyMap();
+  }
+
   @Override public Map<String, List<String>> toMultimap() {
     return Collections.emptyMap();
   }
@@ -49,10 +54,22 @@ public MissingValue(String name) {
     return Collections.emptyList();
   }
 
+  @Nonnull @Override public Optional<String> toOptional() {
+    return Optional.empty();
+  }
+
+  @Nonnull @Override public <T> List<T> toList(@Nonnull Class<T> type) {
+    return Collections.emptyList();
+  }
+
   @Nonnull @Override public Set<String> toSet() {
     return Collections.emptySet();
   }
 
+  @Nonnull @Override public <T> Set<T> toSet(@Nonnull Class<T> type) {
+    return Collections.emptySet();
+  }
+
   @Override public String toString() {
     return "<missing>";
   }

modules/jooby-apt/src/test/java/io/jooby/apt/MvcModuleCompilerRunner.java

@@ -20,6 +20,7 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Stream;
 
 import static org.junit.Assert.assertTrue;
 
@@ -46,7 +47,7 @@ public MvcModuleCompilerRunner(Object instance, boolean debug) throws Exception
   private String[] sourceNames(Class input) {
     List<String> result = new ArrayList<>();
     while (input != Object.class) {
-      result.add(input.getSimpleName() + ".java");
+      result.add(input.getName());
       input = input.getSuperclass();
     }
     return result.toArray(new String[result.size()]);
@@ -97,10 +98,14 @@ private MvcModuleCompilerRunner module(boolean debug, SneakyThrows.Consumer<Joob
   }
 
   private static List<JavaFileObject> sources(String... names) throws MalformedURLException {
-    Path basedir = basedir().resolve("src").resolve("test").resolve("java").resolve("source");
+    Path basedir = basedir().resolve("src").resolve("test").resolve("java");
     List<JavaFileObject> sources = new ArrayList<>();
     for (String name : names) {
-      Path path = basedir.resolve(name);
+      String[] segments = name.split("\\.");
+      Path path = Stream.of(segments)
+          .limit(segments.length - 1)
+          .reduce(basedir, Path::resolve, Path::resolve);
+      path = path.resolve(segments[segments.length - 1] + ".java");
       assertTrue(path.toString(), Files.exists(path));
       sources.add(JavaFileObjects.forResource(path.toUri().toURL()));
     }

modules/jooby-apt/src/test/java/tests/Expected1786b.java

@@ -1,6 +1,5 @@
 package tests;
 
-import io.jooby.Context;
 import io.jooby.Extension;
 import io.jooby.MvcFactory;
 import io.jooby.exception.MissingValueException;

modules/jooby-apt/src/test/java/tests/i1806/C1806.java

@@ -0,0 +1,14 @@
+package tests.i1806;
+
+import io.jooby.annotations.GET;
+import io.jooby.annotations.QueryParam;
+
+import java.util.List;
+
+public class C1806 {
+  @GET("/1806/c")
+  public List<String> sayHi(@QueryParam List<String> names) {
+    return names;
+  }
+
+}

modules/jooby-apt/src/test/java/tests/i1806/Issue1806.java

@@ -0,0 +1,22 @@
+package tests.i1806;
+
+import io.jooby.MockRouter;
+import io.jooby.apt.MvcModuleCompilerRunner;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue1806 {
+
+  @Test
+  public void shouldNotGetListWithNullValue() throws Exception {
+    new MvcModuleCompilerRunner(new C1806())
+        .debugModule(app -> {
+          MockRouter router = new MockRouter(app);
+          assertEquals(Collections.emptyList(), router.get("/1806/c").value());
+        });
+  }
+
+}

tests/src/test/java/io/jooby/i1806/C1806.java

@@ -0,0 +1,13 @@
+package io.jooby.i1806;
+
+import io.jooby.annotations.GET;
+import io.jooby.annotations.QueryParam;
+
+import java.util.List;
+
+public class C1806 {
+  @GET("/1806/c")
+  public List<String> sayHi(@QueryParam List<String> names) {
+    return names;
+  }
+}

tests/src/test/java/io/jooby/i1806/Issue1806.java

@@ -0,0 +1,23 @@
+package io.jooby.i1806;
+
+import io.jooby.junit.ServerTest;
+import io.jooby.junit.ServerTestRunner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue1806 {
+  @ServerTest
+  public void shouldNotGetListWithNullValue(ServerTestRunner runner) {
+    runner.define(app -> {
+      app.mvc(new C1806());
+      app.get("/1806/s", ctx -> ctx.query("names").toList(String.class));
+    }).ready(client -> {
+      client.get("/1806/s", rsp -> {
+        assertEquals("[]", rsp.body().string());
+      });
+      client.get("/1806/c", rsp -> {
+        assertEquals("[]", rsp.body().string());
+      });
+    });
+  }
+}