Imported tests from Google

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java

@@ -194,6 +194,17 @@ public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
         return this;
     }
 
+    /**
+     * Registers {@code type} identified by {@code label}. Labels are case sensitive.
+     *
+     * @throws IllegalArgumentException if either {@code type} or {@code label} have already been
+     *     registered on this type adapter.
+     */
+    public RuntimeTypeAdapterFactory<T> registerSubtype(Class<? extends T> type) {
+        registerSubtype(type, type.getSimpleName());
+        return this;
+    }
+
     private void initMaps(
             Gson gson,
             Map<String, TypeAdapter<?>> labelToDelegate,

src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactoryTests.java

@@ -0,0 +1,224 @@
+package ch.usi.inf.sa4.sanmarinoes.smarthut.config;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonParseException;
+import com.google.gson.TypeAdapterFactory;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Copyright (C) 2011 Google Inc.
+ *
+ * <p>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
+ *
+ * <p>http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * <p>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.
+ */
+public final class RuntimeTypeAdapterFactoryTests {
+
+    @Test
+    public void testRuntimeTypeAdapter() {
+        RuntimeTypeAdapterFactory<BillingInstrument> rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class)
+                        .registerSubtype(CreditCard.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(rta).create();
+
+        CreditCard original = new CreditCard("Jesse", 234);
+        assertEquals(
+                "{\"type\":\"CreditCard\",\"cvv\":234,\"ownerName\":\"Jesse\"}",
+                gson.toJson(original, BillingInstrument.class));
+        BillingInstrument deserialized =
+                gson.fromJson(
+                        "{type:'CreditCard',cvv:234,ownerName:'Jesse'}", BillingInstrument.class);
+        assertEquals("Jesse", deserialized.ownerName);
+        assertTrue(deserialized instanceof CreditCard);
+    }
+
+    @Test
+    public void testRuntimeTypeIsBaseType() {
+        TypeAdapterFactory rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class, "type", false)
+                        .registerSubtype(BillingInstrument.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(rta).create();
+
+        BillingInstrument original = new BillingInstrument("Jesse");
+        assertEquals(
+                "{\"type\":\"BillingInstrument\",\"ownerName\":\"Jesse\"}",
+                gson.toJson(original, BillingInstrument.class));
+        BillingInstrument deserialized =
+                gson.fromJson(
+                        "{type:'BillingInstrument',ownerName:'Jesse'}", BillingInstrument.class);
+        assertEquals("Jesse", deserialized.ownerName);
+    }
+
+    @Test
+    public void testNullBaseType() {
+        try {
+            RuntimeTypeAdapterFactory.of(null);
+            fail();
+        } catch (NullPointerException expected) {
+        }
+    }
+
+    @Test
+    public void testNullTypeFieldName() {
+        try {
+            RuntimeTypeAdapterFactory.of(BillingInstrument.class, null);
+            fail();
+        } catch (NullPointerException expected) {
+        }
+    }
+
+    @Test
+    public void testNullSubtype() {
+        RuntimeTypeAdapterFactory<BillingInstrument> rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class);
+        try {
+            rta.registerSubtype(null);
+            fail();
+        } catch (NullPointerException expected) {
+        }
+    }
+
+    @Test
+    public void testNullLabel() {
+        RuntimeTypeAdapterFactory<BillingInstrument> rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class);
+        try {
+            rta.registerSubtype(CreditCard.class, null);
+            fail();
+        } catch (NullPointerException expected) {
+        }
+    }
+
+    @Test
+    public void testDuplicateSubtype() {
+        RuntimeTypeAdapterFactory<BillingInstrument> rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class);
+        rta.registerSubtype(CreditCard.class, "CC");
+        try {
+            rta.registerSubtype(CreditCard.class, "Visa");
+            fail();
+        } catch (IllegalArgumentException expected) {
+        }
+    }
+
+    @Test
+    public void testDuplicateLabel() {
+        RuntimeTypeAdapterFactory<BillingInstrument> rta =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class);
+        rta.registerSubtype(CreditCard.class, "CC");
+        try {
+            rta.registerSubtype(BankTransfer.class, "CC");
+            fail();
+        } catch (IllegalArgumentException expected) {
+        }
+    }
+
+    @Test
+    public void testDeserializeMissingTypeField() {
+        TypeAdapterFactory billingAdapter =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class)
+                        .registerSubtype(CreditCard.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(billingAdapter).create();
+        try {
+            gson.fromJson("{ownerName:'Jesse'}", BillingInstrument.class);
+            fail();
+        } catch (JsonParseException expected) {
+        }
+    }
+
+    @Test
+    public void testDeserializeMissingSubtype() {
+        TypeAdapterFactory billingAdapter =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class)
+                        .registerSubtype(BankTransfer.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(billingAdapter).create();
+        try {
+            gson.fromJson("{type:'CreditCard',ownerName:'Jesse'}", BillingInstrument.class);
+            fail();
+        } catch (JsonParseException expected) {
+        }
+    }
+
+    @Test
+    public void testSerializeMissingSubtype() {
+        TypeAdapterFactory billingAdapter =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class)
+                        .registerSubtype(BankTransfer.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(billingAdapter).create();
+        try {
+            gson.toJson(new CreditCard("Jesse", 456), BillingInstrument.class);
+            fail();
+        } catch (JsonParseException expected) {
+        }
+    }
+
+    @Test
+    public void testSerializeCollidingTypeFieldName() {
+        TypeAdapterFactory billingAdapter =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class, "cvv")
+                        .registerSubtype(CreditCard.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(billingAdapter).create();
+        try {
+            gson.toJson(new CreditCard("Jesse", 456), BillingInstrument.class);
+            fail();
+        } catch (JsonParseException expected) {
+        }
+    }
+
+    @Test
+    public void testSerializeWrappedNullValue() {
+        TypeAdapterFactory billingAdapter =
+                RuntimeTypeAdapterFactory.of(BillingInstrument.class)
+                        .registerSubtype(CreditCard.class)
+                        .registerSubtype(BankTransfer.class);
+        Gson gson = new GsonBuilder().registerTypeAdapterFactory(billingAdapter).create();
+        String serialized =
+                gson.toJson(new BillingInstrumentWrapper(null), BillingInstrumentWrapper.class);
+        BillingInstrumentWrapper deserialized =
+                gson.fromJson(serialized, BillingInstrumentWrapper.class);
+        assertNull(deserialized.instrument);
+    }
+
+    static class BillingInstrumentWrapper {
+        BillingInstrument instrument;
+
+        BillingInstrumentWrapper(BillingInstrument instrument) {
+            this.instrument = instrument;
+        }
+    }
+
+    static class BillingInstrument {
+        private final String ownerName;
+
+        BillingInstrument(String ownerName) {
+            this.ownerName = ownerName;
+        }
+    }
+
+    static class CreditCard extends BillingInstrument {
+        int cvv;
+
+        CreditCard(String ownerName, int cvv) {
+            super(ownerName);
+            this.cvv = cvv;
+        }
+    }
+
+    static class BankTransfer extends BillingInstrument {
+        int bankAccount;
+
+        BankTransfer(String ownerName, int bankAccount) {
+            super(ownerName);
+            this.bankAccount = bankAccount;
+        }
+    }
+}