Allow null to be passed to withPgClient/withPgClientTransaction (#462)

Author: benjie

.changeset/chilled-squids-admire.md

@@ -0,0 +1,6 @@
+---
+"@dataplan/pg": patch
+"postgraphile": patch
+---
+
+Allow 'null' to be passed to `withPgClient`/`withPgClientTransaction`

grafast/dataplan-pg/src/steps/withPgClient.ts

@@ -1,5 +1,5 @@
 import type { GrafastResultsList, GrafastValuesList } from "grafast";
-import { ExecutableStep } from "grafast";
+import { constant, ExecutableStep } from "grafast";
 
 import type { PgClient, PgExecutor, WithPgClient } from "../executor";
 
@@ -70,18 +70,29 @@ export class WithPgClientStep<
 
 export function withPgClient<TData, TResult>(
   executor: PgExecutor,
-  $data: ExecutableStep<TData>,
+  $data:
+    | ExecutableStep<TData>
+    | (TData extends null | undefined ? null | undefined : never),
   callback: WithPgClientStepCallback<TData, TResult>,
 ) {
-  return new WithPgClientStep(executor, $data, callback);
+  return new WithPgClientStep(
+    executor,
+    $data ?? constant($data as TData),
+    callback,
+  );
 }
 
 export function withPgClientTransaction<TData, TResult>(
   executor: PgExecutor,
-  $data: ExecutableStep<TData>,
+  $data:
+    | ExecutableStep<TData>
+    | (TData extends null | undefined ? null | undefined : never),
   callback: WithPgClientStepCallback<TData, TResult>,
 ) {
-  return withPgClient(executor, $data, (client, data) =>
-    client.withTransaction((txClient) => callback(txClient, data)),
+  return withPgClient(
+    executor,
+    $data ?? constant($data as TData),
+    (client, data) =>
+      client.withTransaction((txClient) => callback(txClient, data)),
   );
 }

postgraphile/website/postgraphile/make-extend-schema-plugin.md

@@ -519,11 +519,12 @@ export const MyRegisterUserMutationPlugin = makeExtendSchemaPlugin((build) => {
     `,
     plans: {
       Mutation: {
-        registerUser() {
+        registerUser(_, fieldArgs) {
+          const $input = fieldArgs.getRaw("input");
           const $user = withPgClientTransaction(
             executor,
-            null,
-            async (pgClient) => {
+            $input,
+            async (pgClient, input) => {
               // Our custom logic to register the user:
               const {
                 rows: [user],
@@ -532,14 +533,14 @@ export const MyRegisterUserMutationPlugin = makeExtendSchemaPlugin((build) => {
                   INSERT INTO app_public.users (name, email, bio)
                   VALUES ($1, $2, $3)
                   RETURNING *`,
-                values: [args.input.name, args.input.email, args.input.bio],
+                values: [input.name, input.email, input.bio],
               });
 
               // Send the email. If this fails then the error will be caught
               // and the transaction rolled back; it will be as if the user
               // never registered
               await mockSendEmail(
-                args.input.email,
+                input.email,
                 "Welcome to my site",
                 `You're user ${user.id} - thanks for being awesome`,
               );