chore: add shared types

Author: TomokiMiyauci

types.ts

@@ -0,0 +1,66 @@
+import { MessageType } from "./constants.ts";
+import { ExecutionArgs, GraphQLError, json, PartialBy } from "./deps.ts";
+
+interface BaseMessage {
+  type: MessageType;
+}
+
+type PartialGraphQLParameter = keyof Omit<GraphQLParameters, "query">;
+
+export interface SubscribeMessage extends BaseMessage {
+  type: MessageType.Subscribe;
+  payload: Readonly<PartialGraphQLParameters>;
+}
+
+export type PartialGraphQLParameters = PartialBy<
+  GraphQLParameters,
+  PartialGraphQLParameter
+>;
+
+/** GraphQL over HTTP Request parameters.
+ * @see https://graphql.github.io/graphql-over-http/draft/#sec-Request-Parameters
+ */
+export type GraphQLParameters = {
+  /** A Document containing GraphQL Operations and Fragments to execute. */
+  query: string;
+
+  /** Values for any Variables defined by the Operation. */
+  variableValues: Record<string, json> | null;
+
+  /** The name of the Operation in the Document to execute. */
+  operationName: string | null;
+
+  /** Reserved for implementors to extend the protocol however they see fit. */
+  extensions: Record<string, json> | null;
+};
+
+export interface ExecutionResult<
+  Data = Record<string, unknown>,
+  Extensions = Record<string, unknown>,
+> {
+  errors?: ReadonlyArray<GraphQLError>;
+  data?: Data | null;
+  extensions?: Extensions;
+}
+
+export interface NextMessage extends BaseMessage {
+  type: MessageType.Next;
+  payload: ExecutionResult;
+}
+
+export interface ErrorMessage extends BaseMessage {
+  type: MessageType.Error;
+  payload: GraphQLError[];
+}
+
+export interface CompleteMessage extends BaseMessage {
+  type: MessageType.Complete;
+}
+
+export type Message =
+  | SubscribeMessage
+  | NextMessage
+  | ErrorMessage
+  | CompleteMessage;
+
+export type GraphQLExecutionArgs = PartialBy<ExecutionArgs, "document">;