Merge pull request #716 from exacaster/unify_error_responses

Unify error responses

server/src/main/java/com/exacaster/lighter/IndexController.java

@@ -6,8 +6,11 @@
 import io.micronaut.http.annotation.Controller;
 import io.micronaut.http.annotation.Get;
 import io.micronaut.http.server.types.files.StreamedFile;
+import io.swagger.v3.oas.annotations.Hidden;
+
 import java.util.Optional;
 
+@Hidden
 @Controller("/lighter")
 public class IndexController {
 

server/src/main/java/com/exacaster/lighter/application/sessions/SessionService.java

@@ -5,6 +5,7 @@
 import com.exacaster.lighter.application.ApplicationState;
 import com.exacaster.lighter.application.ApplicationType;
 import com.exacaster.lighter.application.SubmitParams;
+import com.exacaster.lighter.application.sessions.exceptions.InvalidSessionStateException;
 import com.exacaster.lighter.application.sessions.processors.StatementHandler;
 import com.exacaster.lighter.backend.Backend;
 import com.exacaster.lighter.storage.ApplicationStorage;
@@ -107,14 +108,14 @@ public void killOne(Application app) {
         applicationStorage.saveApplication(ApplicationBuilder.builder(app).setState(ApplicationState.KILLED).build());
     }
 
-    public StatementCreationResult createStatement(String id, Statement statement) {
+    public Optional<Statement> createStatement(String id, Statement statement) {
         return this.fetchOne(id, true).map(application -> {
             if (!application.getState().isComplete()) {
-                return new StatementCreationResult.StatementCreated(statementHandler.processStatement(application.getId(), statement));
+                return statementHandler.processStatement(application.getId(), statement);
             } else {
-                return new StatementCreationResult.SessionInInvalidState(application.getState());
+                throw new InvalidSessionStateException(application.getState());
             }
-        }).orElse(new StatementCreationResult.NoSessionExists());
+        });
     }
 
     public Statement getStatement(String id, String statementId) {

server/src/main/java/com/exacaster/lighter/application/sessions/Statement.java

@@ -3,6 +3,8 @@
 import com.exacaster.lighter.application.sessions.processors.Output;
 import io.micronaut.core.annotation.Introspected;
 import io.micronaut.core.annotation.Nullable;
+
+import javax.validation.constraints.NotNull;
 import java.time.LocalDateTime;
 import java.util.StringJoiner;
 
@@ -26,6 +28,7 @@ public String getId() {
         return id;
     }
 
+    @NotNull
     public String getCode() {
         return code;
     }

server/src/main/java/com/exacaster/lighter/application/sessions/exceptions/InvalidSessionStateException.java

@@ -0,0 +1,23 @@
+package com.exacaster.lighter.application.sessions.exceptions;
+
+import com.exacaster.lighter.application.ApplicationState;
+
+public class InvalidSessionStateException extends RuntimeException {
+    private final ApplicationState sessionState;
+
+    public InvalidSessionStateException(ApplicationState state) {
+        super("Invalid session state: " + state);
+        this.sessionState = state;
+    }
+
+    public ApplicationState getSessionState() {
+        return sessionState;
+    }
+
+    @Override
+    public String toString() {
+        return "InvalidSessionStateException{" +
+                "sessionState=" + sessionState +
+                '}';
+    }
+}

server/src/main/java/com/exacaster/lighter/rest/BatchController.java

@@ -17,9 +17,13 @@
 import io.micronaut.http.annotation.Post;
 import io.micronaut.http.annotation.QueryValue;
 import io.micronaut.validation.Validated;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import io.swagger.v3.oas.annotations.tags.Tags;
+
 import java.util.Optional;
 import javax.validation.Valid;
 
+@Tags(@Tag(name = "Batches"))
 @Validated
 @Controller("/lighter/api/batches")
 public class BatchController {

server/src/main/java/com/exacaster/lighter/rest/ConfigurationController.java

@@ -3,7 +3,10 @@
 import com.exacaster.lighter.configuration.AppConfiguration;
 import io.micronaut.http.annotation.Controller;
 import io.micronaut.http.annotation.Get;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import io.swagger.v3.oas.annotations.tags.Tags;
 
+@Tags(@Tag(name = "Configuration"))
 @Controller("/lighter/api/configuration")
 public class ConfigurationController {
 

server/src/main/java/com/exacaster/lighter/rest/SessionController.java

@@ -5,14 +5,12 @@
 import com.exacaster.lighter.application.SubmitParams;
 import com.exacaster.lighter.application.sessions.SessionService;
 import com.exacaster.lighter.application.sessions.Statement;
-import com.exacaster.lighter.application.sessions.StatementCreationResultMapper;
 import com.exacaster.lighter.application.sessions.StatementList;
 import com.exacaster.lighter.log.LogService;
+import com.exacaster.lighter.rest.exceptions.ErrorResponse;
 import com.exacaster.lighter.rest.magic.SessionList;
 import com.exacaster.lighter.rest.magic.SparkMagicCompatibility;
-import com.exacaster.lighter.rest.mappers.StatementCreationResultToApiResponseMapper;
 import io.micronaut.core.annotation.Nullable;
-import io.micronaut.http.HttpResponse;
 import io.micronaut.http.HttpStatus;
 import io.micronaut.http.annotation.Body;
 import io.micronaut.http.annotation.Controller;
@@ -28,6 +26,8 @@
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import io.swagger.v3.oas.annotations.tags.Tags;
 
 import javax.validation.Valid;
 import java.util.HashMap;
@@ -36,19 +36,18 @@
 import java.util.Optional;
 
 @Validated
+@Tags(@Tag(name = "Sessions"))
 @Controller("/lighter/api/sessions")
 public class SessionController {
 
     private final SessionService sessionService;
     private final LogService logService;
     private final SparkMagicCompatibility magicCompatibility;
-    private final StatementCreationResultMapper<HttpResponse> statementCreationResultMapper;
 
     public SessionController(SessionService sessionService, LogService logService, SparkMagicCompatibility magicCompatibility) {
         this.sessionService = sessionService;
         this.logService = logService;
         this.magicCompatibility = magicCompatibility;
-        this.statementCreationResultMapper = new StatementCreationResultToApiResponseMapper();
     }
 
     @Get
@@ -63,7 +62,7 @@ public Object get(@QueryValue(defaultValue = "0") Integer from,
 
     @Post
     @Status(HttpStatus.CREATED)
-    public Application create(@Body SubmitParams session) {
+    public Application create(@Valid @Body SubmitParams session) {
         return sessionService.createSession(session);
     }
 
@@ -103,11 +102,11 @@ public Optional<Object> getLog(@PathVariable String id, @Nullable @Header("X-Com
     @Post("/{id}/statements")
     @ApiResponses(value = {
             @ApiResponse(responseCode = "201", description = "Statement created", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = Statement.class))}),
-            @ApiResponse(responseCode = "400", description = "Session in invalid state", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = StatementCreationResultToApiResponseMapper.InvalidSessionStateResponse.class))}),
-            @ApiResponse(responseCode = "404", description = "Session not found")
+            @ApiResponse(responseCode = "400", description = "Session in invalid state", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = ErrorResponse.class))}),
+            @ApiResponse(responseCode = "404", description = "Session not found", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = ErrorResponse.class))})
     })
-    public HttpResponse postStatements(@PathVariable String id, @Valid @Body Statement statement) {
-        return sessionService.createStatement(id, statement).map(statementCreationResultMapper);
+    public Optional<Statement> postStatements(@PathVariable String id, @Valid @Body Statement statement) {
+        return sessionService.createStatement(id, statement);
     }
 
     @Get("/{id}/statements")

server/src/main/java/com/exacaster/lighter/rest/exceptions/ApiErrorResponseProcessor.java

@@ -0,0 +1,28 @@
+package com.exacaster.lighter.rest.exceptions;
+
+import io.micronaut.context.annotation.Primary;
+import io.micronaut.core.annotation.NonNull;
+import io.micronaut.http.HttpMethod;
+import io.micronaut.http.MediaType;
+import io.micronaut.http.MutableHttpResponse;
+import io.micronaut.http.server.exceptions.response.ErrorContext;
+import io.micronaut.http.server.exceptions.response.ErrorResponseProcessor;
+
+import javax.inject.Singleton;
+
+@Primary
+@Singleton
+public class ApiErrorResponseProcessor implements ErrorResponseProcessor<ErrorResponse> {
+    @NonNull
+    @Override
+    public MutableHttpResponse<ErrorResponse> processResponse(@NonNull ErrorContext errorContext,
+                                                              @NonNull MutableHttpResponse response) {
+        if (errorContext.getRequest().getMethod() == HttpMethod.HEAD) {
+            return (MutableHttpResponse<ErrorResponse>) response;
+        }
+        var path = errorContext.getRequest().getUri();
+        var error = new ErrorResponse(response.getStatus().getReason(), path, errorContext.getErrors());
+
+        return response.body(error).contentType(MediaType.APPLICATION_JSON_TYPE);
+    }
+}

server/src/main/java/com/exacaster/lighter/rest/exceptions/DetailedError.java

@@ -0,0 +1,34 @@
+package com.exacaster.lighter.rest.exceptions;
+
+import io.micronaut.core.annotation.Introspected;
+import io.micronaut.http.server.exceptions.response.Error;
+
+@Introspected
+public class DetailedError implements Error {
+
+    private final String message;
+
+    private final Object details;
+
+    public DetailedError(String message, Object details) {
+        this.message = message;
+        this.details = details;
+    }
+
+    @Override
+    public String getMessage() {
+        return message;
+    }
+
+    public Object getDetails() {
+        return details;
+    }
+
+    @Override
+    public String toString() {
+        return "DetailedError{" +
+                "message='" + message + '\'' +
+                ", details=" + details +
+                '}';
+    }
+}

server/src/main/java/com/exacaster/lighter/rest/exceptions/ErrorResponse.java

@@ -0,0 +1,46 @@
+package com.exacaster.lighter.rest.exceptions;
+
+import io.micronaut.core.annotation.Introspected;
+import io.micronaut.http.server.exceptions.response.Error;
+
+import java.net.URI;
+import java.util.List;
+
+@Introspected
+public class ErrorResponse {
+    private final String message;
+    private final URI path;
+    private final List<Error> errors;
+
+    public ErrorResponse(String message, URI path, List<Error> errors) {
+        this.message = message;
+        this.path = path;
+        this.errors = errors;
+    }
+
+    public ErrorResponse(String message, URI path) {
+        this(message, path, List.of());
+    }
+
+
+    public String getMessage() {
+        return message;
+    }
+
+    public URI getPath() {
+        return path;
+    }
+
+    public List<Error> getErrors() {
+        return errors;
+    }
+
+    @Override
+    public String toString() {
+        return "ErrorResponse{" +
+                "message='" + message + '\'' +
+                ", path=" + path +
+                ", errors=" + errors +
+                '}';
+    }
+}

server/src/main/java/com/exacaster/lighter/rest/exceptions/InvalidSessionStateExceptionHandler.java

@@ -0,0 +1,39 @@
+package com.exacaster.lighter.rest.exceptions;
+
+import com.exacaster.lighter.application.sessions.exceptions.InvalidSessionStateException;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.http.HttpRequest;
+import io.micronaut.http.HttpResponse;
+import io.micronaut.http.MutableHttpResponse;
+import io.micronaut.http.annotation.Produces;
+import io.micronaut.http.server.exceptions.ExceptionHandler;
+import io.micronaut.http.server.exceptions.response.ErrorContext;
+import io.micronaut.http.server.exceptions.response.ErrorResponseProcessor;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+
+import java.util.List;
+import java.util.Map;
+
+@Produces
+@Singleton
+@Requires(classes = InvalidSessionStateException.class)
+public class InvalidSessionStateExceptionHandler implements ExceptionHandler<InvalidSessionStateException, HttpResponse<?>> {
+
+    private final ErrorResponseProcessor<?> responseProcessor;
+
+    @Inject
+    public InvalidSessionStateExceptionHandler(ErrorResponseProcessor<?> responseProcessor) {
+        this.responseProcessor = responseProcessor;
+    }
+
+    @Override
+    public HttpResponse<?> handle(HttpRequest request, InvalidSessionStateException exception) {
+        final ErrorContext.Builder contextBuilder = ErrorContext.builder(request).cause(exception);
+        MutableHttpResponse<?> response = HttpResponse.badRequest();
+
+        return responseProcessor.processResponse(contextBuilder
+                .error(new DetailedError(exception.getMessage(), Map.of("sessionState", exception.getSessionState())))
+                .build(), response);
+    }
+}