feat(hooks): add postgraphile:liveSubscribe:executionResult hook (#1483)

graphile · May 26, 2021 · 73fe801 · 73fe801
1 parent 95a3451
commit 73fe801
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Showing 2 changed files with 48 additions and 2 deletions.
diff --git a/src/postgraphile/http/liveSubscribe.ts b/src/postgraphile/http/liveSubscribe.ts
@@ -32,10 +32,12 @@ type mixed = any;
  *
  * @internal
  */
-export function makeLiveSubscribe(_params: {
+export function makeLiveSubscribe(params: {
   options: CreateRequestHandlerOptions;
   pluginHook: PluginHookFn;
 }): typeof subscribe {
+  const { pluginHook } = params;
+
   return function liveSubscribe(
     argsOrSchema: any | GraphQLSchema,
     document?: DocumentNode,
@@ -106,7 +108,7 @@ export function makeLiveSubscribe(_params: {
        * that it can clean up old listeners; we do this with the `finally` block.
        */
       try {
-        return await execute(
+        const executionResult = execute(
           schema,
           document,
           payload,
@@ -115,6 +117,23 @@ export function makeLiveSubscribe(_params: {
           operationName,
           fieldResolver,
         );
+
+        const hookedExecutionResult = pluginHook(
+          'postgraphile:liveSubscribe:executionResult',
+          executionResult,
+          {
+            schema,
+            document,
+            rootValue,
+            contextValue,
+            variableValues,
+            operationName,
+            fieldResolver,
+            subscribeFieldResolver,
+          },
+        );
+
+        return await hookedExecutionResult;
       } finally {
         if (payload && typeof payload.release === 'function') {
           payload.release();

diff --git a/src/postgraphile/pluginHook.ts b/src/postgraphile/pluginHook.ts
@@ -13,6 +13,8 @@ import { Extra as GraphQLWSContextExtra } from 'graphql-ws/lib/use/ws';
 import { ExecutionParams } from 'subscriptions-transport-ws';
 import { PostGraphileResponse } from './http/frameworks';
 
+type PromiseOrValue<T> = T | Promise<T>;
+
 // tslint:disable-next-line no-any
 export type HookFn<TArg, TContext = any> = (arg: TArg, context: TContext) => TArg;
 export type PluginHookFn = <TArgument, TContext = Record<string, any>>(
@@ -99,6 +101,31 @@ export interface PostGraphilePlugin {
     }
   >;
 
+  'postgraphile:liveSubscribe:executionResult'?: HookFn<
+    PromiseOrValue<
+      graphql.ExecutionResult<
+        {
+          [key: string]: any;
+        },
+        {
+          [key: string]: any;
+        }
+      >
+    >,
+    {
+      schema: graphql.GraphQLSchema;
+      document: graphql.DocumentNode;
+      rootValue: any;
+      contextValue: any;
+      variableValues: { [key: string]: any } | undefined;
+      operationName: string | undefined;
+      fieldResolver: graphql.GraphQLFieldResolver<any, any, { [argName: string]: any }> | undefined;
+      subscribeFieldResolver:
+        | graphql.GraphQLFieldResolver<any, any, { [argName: string]: any }>
+        | undefined;
+    }
+  >;
+
   withPostGraphileContext?: HookFn<WithPostGraphileContextFn>;
 }
 type HookName = keyof PostGraphilePlugin;