Use target type (not element type) when choosing a deserializer for numbers

configlib-core/src/main/java/de/exlll/configlib/Serializers.java

@@ -77,10 +77,10 @@ public Number serialize(Number element) {
 
         @Override
         public Number deserialize(Number element) {
-            if (Reflect.isIntegerType(element.getClass())) {
+            if (Reflect.isIntegerType(cls)) {
                 return deserializeFromIntegerType(element);
             }
-            if (Reflect.isFloatingPointType(element.getClass())) {
+            if (Reflect.isFloatingPointType(cls)) {
                 return deserializeFromFloatingPointType(element);
             }
             String clsName = element.getClass().getSimpleName();

configlib-core/src/test/java/de/exlll/configlib/SerializersTest.java

@@ -61,17 +61,6 @@ void numberSerializerRequiresValidNumberType() {
         );
     }
 
-    @Test
-    void numberSerializerDeserializeInvalidType() {
-        NumberSerializer serializer = new NumberSerializer(int.class);
-
-        assertThrowsConfigurationException(
-                () -> serializer.deserialize(BigInteger.ONE),
-                "Cannot deserialize element '1' of type BigInteger.\n" +
-                "This serializer only supports primitive number types and their wrapper types."
-        );
-    }
-
     @ParameterizedTest
     @ValueSource(classes = {
             byte.class, Byte.class,

configlib-yaml/src/test/java/de/exlll/configlib/YamlConfigurationsTest.java

@@ -12,9 +12,12 @@
 import java.nio.file.FileSystem;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.List;
 
+import static de.exlll.configlib.TestUtils.asList;
 import static de.exlll.configlib.TestUtils.createPlatformSpecificFilePath;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 class YamlConfigurationsTest {
     private static final FieldFilter includeI = field -> field.getName().equals("i");
@@ -230,4 +233,79 @@ private void writeStringToStream(String string) {
     private InputStream inputFromOutput() {
         return new ByteArrayInputStream(outputStream.toByteArray());
     }
+
+    @Configuration
+    private static final class DoublesConfig {
+        double d;
+        Double boxed;
+        List<Double> list;
+    }
+
+    @Test
+    void loadYamlConfigurationDoublesAllDecimal() {
+        writeStringToFile(
+                """
+                d: 10.0
+                boxed: 20.0
+                list:
+                  - 1.0
+                  - 2.0
+                  - 3.0
+                """
+        );
+        DoublesConfig config = YamlConfigurations.load(yamlFile, DoublesConfig.class);
+        assertEquals(10.0, config.d);
+        assertEquals(20.0, config.boxed);
+        assertEquals(asList(1.0, 2.0, 3.0), config.list);
+    }
+
+    @Test
+    void loadYamlConfigurationDoublesUnboxed() {
+        writeStringToFile("d: 10");
+        DoublesConfig config = YamlConfigurations.load(yamlFile, DoublesConfig.class);
+        assertEquals(10.0, config.d);
+    }
+
+    @Test
+    void loadYamlConfigurationDoublesBoxed() {
+        writeStringToFile("boxed: 20");
+        DoublesConfig config = YamlConfigurations.load(yamlFile, DoublesConfig.class);
+        assertEquals(20.0, config.boxed);
+    }
+
+    @Test
+    void loadYamlConfigurationDoublesCollection() {
+        writeStringToFile(
+                """
+                list:
+                  - 1.0
+                  - 2
+                  - 3.0
+                """
+        );
+        DoublesConfig config = YamlConfigurations.load(yamlFile, DoublesConfig.class);
+        assertEquals(asList(1.0, 2.0, 3.0), config.list);
+    }
+
+    @Test
+    void loadYamlConfigurationDoublesWithNulls() {
+        writeStringToFile(
+                """
+                boxed: null
+                list:
+                - null
+                - null
+                - 1.0
+                - 2
+                """
+        );
+        DoublesConfig config = YamlConfigurations.load(
+                yamlFile,
+                DoublesConfig.class,
+                builder -> builder.inputNulls(true)
+        );
+        assertEquals(0.0, config.d);
+        assertNull(config.boxed);
+        assertEquals(asList(null, null, 1.0, 2.0), config.list);
+    }
 }