chore: give liveSubscribe access to options/pluginHook (#1482)

graphile · May 26, 2021 · 95a3451 · 95a3451
1 parent c583026
commit 95a3451
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diff --git a/src/postgraphile/http/liveSubscribe.ts b/src/postgraphile/http/liveSubscribe.ts
@@ -18,111 +18,125 @@ import {
   GraphQLError,
   ExecutionResult,
 } from 'graphql';
+import type { subscribe } from 'graphql';
 import mapAsyncIterator from './mapAsyncIterator';
 import { isAsyncIterable } from 'iterall';
+import { CreateRequestHandlerOptions } from '../../interfaces';
+import { PluginHookFn } from '../pluginHook';
 
 type mixed = any;
 
-export default function liveSubscribe(
-  argsOrSchema: any | GraphQLSchema,
-  document?: DocumentNode,
-  rootValue?: any,
-  contextValue?: any,
-  variableValues?: { [key: string]: any },
-  operationName?: string,
-  fieldResolver?: GraphQLFieldResolver<any, any>,
-  subscribeFieldResolver?: GraphQLFieldResolver<any, any>,
-) {
-  /* eslint-enable no-redeclare */
-  // Extract arguments from object args if provided.
-  return arguments.length === 1
-    ? liveSubscribeImpl(
-        argsOrSchema.schema,
-        argsOrSchema.document,
-        argsOrSchema.rootValue,
-        argsOrSchema.contextValue,
-        argsOrSchema.variableValues,
-        argsOrSchema.operationName,
-        argsOrSchema.fieldResolver,
-        argsOrSchema.subscribeFieldResolver,
-      )
-    : liveSubscribeImpl(
-        argsOrSchema,
-        document as DocumentNode,
-        rootValue,
-        contextValue,
-        variableValues,
-        operationName,
-        fieldResolver,
-        subscribeFieldResolver,
-      );
-}
+/**
+ * This method returns a function compatible with the `subscribe` function from
+ * GraphQL.js, but with enhancements to support live queries.
+ *
+ * @internal
+ */
+export function makeLiveSubscribe(_params: {
+  options: CreateRequestHandlerOptions;
+  pluginHook: PluginHookFn;
+}): typeof subscribe {
+  return function liveSubscribe(
+    argsOrSchema: any | GraphQLSchema,
+    document?: DocumentNode,
+    rootValue?: any,
+    contextValue?: any,
+    variableValues?: { [key: string]: any },
+    operationName?: string,
+    fieldResolver?: GraphQLFieldResolver<any, any>,
+    subscribeFieldResolver?: GraphQLFieldResolver<any, any>,
+  ) {
+    /* eslint-enable no-redeclare */
+    // Extract arguments from object args if provided.
+    return arguments.length === 1
+      ? liveSubscribeImpl(
+          argsOrSchema.schema,
+          argsOrSchema.document,
+          argsOrSchema.rootValue,
+          argsOrSchema.contextValue,
+          argsOrSchema.variableValues,
+          argsOrSchema.operationName,
+          argsOrSchema.fieldResolver,
+          argsOrSchema.subscribeFieldResolver,
+        )
+      : liveSubscribeImpl(
+          argsOrSchema,
+          document as DocumentNode,
+          rootValue,
+          contextValue,
+          variableValues,
+          operationName,
+          fieldResolver,
+          subscribeFieldResolver,
+        );
+  };
 
-function liveSubscribeImpl(
-  schema: GraphQLSchema,
-  document: DocumentNode,
-  rootValue?: any,
-  contextValue?: any,
-  variableValues?: { [key: string]: any },
-  operationName?: string,
-  fieldResolver?: GraphQLFieldResolver<any, any>,
-  subscribeFieldResolver?: GraphQLFieldResolver<any, any>,
-) {
-  const sourcePromise = createSourceEventStream(
-    schema,
-    document,
-    rootValue,
-    contextValue,
-    variableValues,
-    operationName,
-    subscribeFieldResolver,
-  );
+  function liveSubscribeImpl(
+    schema: GraphQLSchema,
+    document: DocumentNode,
+    rootValue?: any,
+    contextValue?: any,
+    variableValues?: { [key: string]: any },
+    operationName?: string,
+    fieldResolver?: GraphQLFieldResolver<any, any>,
+    subscribeFieldResolver?: GraphQLFieldResolver<any, any>,
+  ) {
+    const sourcePromise = createSourceEventStream(
+      schema,
+      document,
+      rootValue,
+      contextValue,
+      variableValues,
+      operationName,
+      subscribeFieldResolver,
+    );
 
-  // For each payload yielded from a subscription, map it over the normal
-  // GraphQL `execute` function, with `payload` as the rootValue.
-  // This implements the "MapSourceToResponseEvent" algorithm described in
-  // the GraphQL specification. The `execute` function provides the
-  // "ExecuteSubscriptionEvent" algorithm, as it is nearly identical to the
-  // "ExecuteQuery" algorithm, for which `execute` is also used.
-  const mapSourceToResponse = async (payload: any) => {
-    /*
-     * GRAPHILE FORK
-     *
-     * We need to tell Graphile Engine when the execution has completed
-     * (because we cannot detect this from inside the GraphQL execution) so
-     * that it can clean up old listeners; we do this with the `finally` block.
-     */
-    try {
-      return await execute(
-        schema,
-        document,
-        payload,
-        contextValue,
-        variableValues,
-        operationName,
-        fieldResolver,
-      );
-    } finally {
-      if (payload && typeof payload.release === 'function') {
-        payload.release();
+    // For each payload yielded from a subscription, map it over the normal
+    // GraphQL `execute` function, with `payload` as the rootValue.
+    // This implements the "MapSourceToResponseEvent" algorithm described in
+    // the GraphQL specification. The `execute` function provides the
+    // "ExecuteSubscriptionEvent" algorithm, as it is nearly identical to the
+    // "ExecuteQuery" algorithm, for which `execute` is also used.
+    const mapSourceToResponse = async (payload: any) => {
+      /*
+       * GRAPHILE FORK
+       *
+       * We need to tell Graphile Engine when the execution has completed
+       * (because we cannot detect this from inside the GraphQL execution) so
+       * that it can clean up old listeners; we do this with the `finally` block.
+       */
+      try {
+        return await execute(
+          schema,
+          document,
+          payload,
+          contextValue,
+          variableValues,
+          operationName,
+          fieldResolver,
+        );
+      } finally {
+        if (payload && typeof payload.release === 'function') {
+          payload.release();
+        }
       }
-    }
-  };
+    };
 
-  // Resolve the Source Stream, then map every source value to a
-  // ExecutionResult value as described above.
-  return sourcePromise.then(
-    resultOrStream =>
-      // Note: Flow can't refine isAsyncIterable, so explicit casts are used.
-      isAsyncIterable(resultOrStream)
-        ? mapAsyncIterator(
-            (resultOrStream as any) as AsyncIterable<mixed>,
-            mapSourceToResponse,
-            reportGraphQLError,
-          )
-        : ((resultOrStream as any) as ExecutionResult),
-    reportGraphQLError,
-  );
+    // Resolve the Source Stream, then map every source value to a
+    // ExecutionResult value as described above.
+    return sourcePromise.then(
+      resultOrStream =>
+        // Note: Flow can't refine isAsyncIterable, so explicit casts are used.
+        isAsyncIterable(resultOrStream)
+          ? mapAsyncIterator(
+              (resultOrStream as any) as AsyncIterable<mixed>,
+              mapSourceToResponse,
+              reportGraphQLError,
+            )
+          : ((resultOrStream as any) as ExecutionResult),
+      reportGraphQLError,
+    );
+  }
 }
 
 /**

diff --git a/src/postgraphile/http/subscriptions.ts b/src/postgraphile/http/subscriptions.ts
@@ -18,7 +18,7 @@ import { useServer } from 'graphql-ws/lib/use/ws';
 import parseUrl = require('parseurl');
 import { pluginHookFromOptions } from '../pluginHook';
 import { isEmpty } from './createPostGraphileHttpRequestHandler';
-import liveSubscribe from './liveSubscribe';
+import { makeLiveSubscribe } from './liveSubscribe';
 
 interface Deferred<T> extends Promise<T> {
   resolve: (input?: T | PromiseLike<T> | undefined) => void;
@@ -70,6 +70,7 @@ export async function enhanceHttpServerWithWebSockets<
     handleErrors,
   } = postgraphileMiddleware;
   const pluginHook = pluginHookFromOptions(options);
+  const liveSubscribe = makeLiveSubscribe({ pluginHook, options });
   const graphqlRoute =
     (subscriptionServerOptions && subscriptionServerOptions.graphqlRoute) ||
     (options.externalUrlBase || '') + (options.graphqlRoute || '/graphql');