Merge pull request #161 from yvasyliev/160-bug-messageevent-doesnt-support-plain-string-in-payload-probable-fix-provided

Fixed #160

Author: yvasyliev

README.md

@@ -50,7 +50,7 @@ This library uses the next third-party dependencies:
    <dependency>
        <groupId>com.github.yvasyliev</groupId>
        <artifactId>java-vk-bots-longpoll-api</artifactId>
-       <version>4.1.0</version>
+       <version>4.1.1</version>
    </dependency>
    ```
 4. Extend `LongPollBot` class and override necessary methods:

pom.xml

@@ -6,7 +6,7 @@
     <groupId>com.github.yvasyliev</groupId>
     <artifactId>java-vk-bots-longpoll-api</artifactId>
     <packaging>jar</packaging>
-    <version>4.1.0</version>
+    <version>4.1.1</version>
     <name>Java VK Bots Long Poll API</name>
     <description>A Java library to create VK bots using Bots Long Poll API</description>
     <url>https://github.com/yvasyliev/java-vk-bots-long-poll-api</url>

src/main/java/api/longpoll/bots/adapters/deserializers/PayloadDeserializer.java

@@ -5,6 +5,7 @@
 import com.google.gson.JsonDeserializer;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonParseException;
+import com.google.gson.JsonSyntaxException;
 
 import java.lang.reflect.Type;
 
@@ -20,7 +21,21 @@ public class PayloadDeserializer implements JsonDeserializer<JsonElement> {
     @Override
     public JsonElement deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext context) throws JsonParseException {
         return jsonElement.isJsonPrimitive() && jsonElement.getAsJsonPrimitive().isString()
-                ? GSON.fromJson(jsonElement.getAsString(), JsonElement.class)
+                ? parseString(jsonElement)
                 : jsonElement;
     }
+
+    /**
+     * Parses string.
+     *
+     * @param jsonElement string value.
+     * @return JSON if provided string is a valid JSON, same string otherwise.
+     */
+    private JsonElement parseString(JsonElement jsonElement) {
+        try {
+            return GSON.fromJson(jsonElement.getAsString(), JsonElement.class);
+        } catch (JsonSyntaxException e) {
+            return jsonElement;
+        }
+    }
 }

src/test/java/api/longpoll/bots/adapters/deserializers/PayloadDeserializerTest.java

@@ -0,0 +1,80 @@
+package api.longpoll.bots.adapters.deserializers;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.annotations.JsonAdapter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PayloadDeserializerTest {
+    Gson gson = new Gson();
+
+    @Test
+    void parseBooleanTest() {
+        String json = "{\"payload\":true}";
+
+        JsonElement payload = gson.fromJson(json, PayloadHolder.class).payload;
+        assertTrue(payload.isJsonPrimitive());
+
+        JsonPrimitive jsonPrimitive = payload.getAsJsonPrimitive();
+        assertTrue(jsonPrimitive.isBoolean());
+        assertTrue(jsonPrimitive.getAsBoolean());
+    }
+
+    @Test
+    void parseStringTest() {
+        String json = "{\"payload\":\"Hello World!\"}";
+
+        JsonElement payload = gson.fromJson(json, PayloadHolder.class).payload;
+        assertTrue(payload.isJsonPrimitive());
+
+        JsonPrimitive jsonPrimitive = payload.getAsJsonPrimitive();
+        assertTrue(jsonPrimitive.isString());
+        assertEquals("Hello World!", jsonPrimitive.getAsString());
+    }
+
+    @Test
+    void parseJsonTest() {
+        String json = "{\"payload\":{\"foo\":\"bar\"}}";
+
+        JsonElement payload = gson.fromJson(json, PayloadHolder.class).payload;
+        assertTrue(payload.isJsonObject());
+
+        JsonObject jsonObject = payload.getAsJsonObject();
+        assertTrue(jsonObject.has("foo"));
+
+        JsonElement foo = jsonObject.get("foo");
+        assertTrue(foo.isJsonPrimitive());
+
+        JsonPrimitive jsonPrimitive = foo.getAsJsonPrimitive();
+        assertTrue(jsonPrimitive.isString());
+        assertEquals("bar", jsonPrimitive.getAsString());
+    }
+
+    @Test
+    void parseStringJsonTest() {
+        String json = "{\"payload\":\"{\\\"foo\\\":\\\"bar\\\"}\"}";
+
+        JsonElement payload = gson.fromJson(json, PayloadHolder.class).payload;
+        assertTrue(payload.isJsonObject());
+
+        JsonObject jsonObject = payload.getAsJsonObject();
+        assertTrue(jsonObject.has("foo"));
+
+        JsonElement foo = jsonObject.get("foo");
+        assertTrue(foo.isJsonPrimitive());
+
+        JsonPrimitive jsonPrimitive = foo.getAsJsonPrimitive();
+        assertTrue(jsonPrimitive.isString());
+        assertEquals("bar", jsonPrimitive.getAsString());
+    }
+
+    static class PayloadHolder {
+        @JsonAdapter(PayloadDeserializer.class)
+        JsonElement payload;
+    }
+}