feat: refactor graphql endpoint (#50)

* feat: add http status constant

Signed-off-by: Jemin <[email protected]>

* feat: move code that converts the type of the response into graphQLClient

Signed-off-by: Jemin <[email protected]>

* feat: update tests to throw LitmusApiException

Signed-off-by: Jemin <[email protected]>

* feat: extract handling response method

Signed-off-by: Jemin <[email protected]>

* feat: remove space

Signed-off-by: Jemin <[email protected]>

* feat: update graphQLClient request body media type

Signed-off-by: Jemin <[email protected]>

* feat: extract okHttpClient close method

Signed-off-by: Jemin <[email protected]>

* feat: update graphqlClient to throw IOException

Signed-off-by: Jemin <[email protected]>

---------

Signed-off-by: Jemin <[email protected]>

Author: jemlog

src/main/java/io/litmuschaos/LitmusClient.java

@@ -0,0 +1,9 @@
+package io.litmuschaos.constants;
+
+public class HttpStatus {
+    public static final int OK = 200;
+    public static final int BAD_REQUEST = 400;
+    public static final int UNAUTHORIZED = 401;
+    public static final int FORBIDDEN = 403;
+    public static final int NOT_FOUND = 404;
+}

src/main/java/io/litmuschaos/constants/HttpStatus.java

@@ -0,0 +1,16 @@
+package io.litmuschaos.exception;
+
+import java.io.IOException;
+
+public class IOExceptionHolder extends RuntimeException {
+
+    IOException exception;
+
+    public IOExceptionHolder(IOException exception) {
+        this.exception = exception;
+    }
+
+    public IOException getException() {
+        return exception;
+    }
+}

src/main/java/io/litmuschaos/exception/IOExceptionHolder.java

@@ -1,47 +1,59 @@
 package io.litmuschaos.graphql;
+import com.jayway.jsonpath.TypeRef;
 import com.netflix.graphql.dgs.client.GraphQLClient;
 import com.netflix.graphql.dgs.client.GraphQLResponse;
 import com.netflix.graphql.dgs.client.HttpResponse;
 import java.io.IOException;
-import java.util.Map;
-
+import io.litmuschaos.constants.HttpStatus;
+import io.litmuschaos.exception.IOExceptionHolder;
+import io.litmuschaos.exception.LitmusApiException;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
 
-import static io.litmuschaos.constants.RequestHeaders.BEARER;
+import static io.litmuschaos.constants.RequestHeaders.*;
 
 
 public class LitmusGraphQLClient {
 
     public final GraphQLClient client;
 
     public LitmusGraphQLClient(OkHttpClient okHttpClient, String host, String token) {
-        client = GraphQLClient.createCustom(host, ((url, headers, body) -> {
+        client = GraphQLClient.createCustom(host, (url, headers, body) -> {
             Request request = new Request.Builder()
                 .url(url)
-                .addHeader("Authorization", BEARER + " " + token)
-                .post(RequestBody.create(body, MediaType.parse("application/json"))
+                .addHeader(AUTHORIZATION, BEARER + " " + token)
+                .post(RequestBody.create(body, MediaType.parse(APPLICATION_JSON + "; " + CHARSET_UTF_8))
             ).build();
 
             try (Response response = okHttpClient.newCall(request).execute()) {
-                if(!response.isSuccessful()) {
-                    throw new IOException("Unexpected code " + response);
-                }
-                return new HttpResponse(response.code(), response.body().string());
-            }catch (IOException e) {
-                throw new RuntimeException(e);
+                return new HttpResponse(HttpStatus.OK, response.body().string());
+            } catch (IOException e) {
+                // requestExecutor cannot throw a checked exception, so wrapped IOException with IOExceptionHolder which is unchecked exception
+                throw new IOExceptionHolder(e);
             }
-        }));
+        });
+    }
+
+    public <T> T query(String query, String operationName, TypeRef<T> type) throws LitmusApiException, IOException {
+        try {
+            GraphQLResponse response = client.executeQuery(query);
+            return handleResponse(response, operationName, type);
+        } catch (IOExceptionHolder e) {
+            throw e.getException();
+        }
     }
 
-    public GraphQLResponse query(String query, Map<String,Object> variables){
-        return client.executeQuery(query, variables);
+    private <T> T handleResponse(GraphQLResponse response, String operationName, TypeRef<T> type) throws LitmusApiException{
+        validateResponse(response);
+        return response.extractValueAsObject(operationName, type);
     }
 
-    public GraphQLResponse query(String query){
-        return client.executeQuery(query);
+    private void validateResponse(GraphQLResponse response) throws LitmusApiException {
+        if (response.hasErrors()){
+            throw new LitmusApiException(response.getErrors().get(0).getMessage());
+        }
     }
 }

src/main/java/io/litmuschaos/graphql/LitmusGraphQLClient.java

@@ -1,6 +1,7 @@
 package io.litmuschaos.http;
 
 import com.google.gson.*;
+import io.litmuschaos.constants.HttpStatus;
 import io.litmuschaos.constants.ResponseBodyFields;
 import io.litmuschaos.exception.LitmusApiException;
 import io.litmuschaos.exception.detailed.*;
@@ -37,13 +38,13 @@ private void handleErrorResponse(Response response) throws LitmusApiException, I
             }
         }
         switch (response.code()) {
-            case 400:
+            case HttpStatus.BAD_REQUEST:
                 throw new BadRequestException(errorMessage);
-            case 401:
+            case HttpStatus.UNAUTHORIZED:
                 throw new UnauthorizedException(errorMessage);
-            case 403:
+            case HttpStatus.FORBIDDEN:
                 throw new ForbiddenException(errorMessage);
-            case 404:
+            case HttpStatus.NOT_FOUND:
                 throw new NotFoundException(errorMessage);
             default:
                 throw new InternalServerErrorException(errorMessage);

src/main/java/io/litmuschaos/http/HttpResponseHandler.java

@@ -11,7 +11,7 @@
 
 import static io.litmuschaos.constants.RequestHeaders.*;
 
-public class LitmusHttpClient implements AutoCloseable{
+public class LitmusHttpClient {
 
     private final OkHttpClient okHttpClient;
     private final HttpResponseHandler httpResponseHandler;
@@ -108,13 +108,4 @@ private String toJson(Object object) {
         Gson gson = new Gson();
         return gson.toJson(object);
     }
-
-    @Override
-    public void close() throws Exception {
-        this.okHttpClient.dispatcher().executorService().shutdown();
-        this.okHttpClient.connectionPool().evictAll();
-        if (this.okHttpClient.cache() != null) {
-            this.okHttpClient.cache().close();
-        }
-    }
 }