improve(document-builder): simplification of all output cases! (#1269)

src/client/handleOutput.ts

@@ -1,4 +1,6 @@
 import type { GraphQLError } from 'graphql'
+import type { Simplify } from 'type-fest'
+import type { SimplifyDeepExcept } from '../documentBuilder/Simplify.js'
 import type { RunTypeHookOnRequestResult } from '../extension/extension.js'
 import { Errors } from '../lib/errors/__.js'
 import type { Grafaid } from '../lib/grafaid/__.js'
@@ -109,7 +111,15 @@ export const handleOutput = (
 
 // dprint-ignore
 export type HandleOutputGraffleRootField<$Context extends Context, $Data extends SomeObjectData, $RootFieldName extends string> =
-  HandleOutputGraffleRootField_Data<ExcludeNull<HandleOutput<$Context, $Data>>, $RootFieldName>
+  HandleOutputGraffleRootField_Data<
+    ExcludeNull<
+      HandleOutput<
+        $Context,
+        SimplifyDeepExcept<$Context['scalars']['typesDecoded'], $Data>
+      >
+    >,
+    $RootFieldName
+  >
 
 // dprint-ignore
 type HandleOutputGraffleRootField_Data<$Output extends Error | SomeObjectData | GraffleExecutionResultEnvelope, $RootFieldName extends string> =
@@ -119,7 +129,13 @@ type HandleOutputGraffleRootField_Data<$Output extends Error | SomeObjectData |
 
 // dprint-ignore
 export type HandleOutput<$Context extends Context, $Data extends SomeObjectData> =
-  HandleOutput_Extensions<$Context, Envelope<$Context, $Data>>
+  HandleOutput_Extensions<
+    $Context,
+    Envelope<
+      $Context,
+      SimplifyDeepExcept<$Context['scalars']['typesDecoded'], $Data>
+    >
+  >
 
 type HandleOutput_Extensions<$Context extends Context, $Envelope extends GraffleExecutionResultEnvelope> =
   HandleOutput_ErrorsReturn<
@@ -168,26 +184,32 @@ type ConfigResolveOutputErrorChannel<$Context extends Context, $Channel extends
 
 // dprint-ignore
 // todo use ObjMap for $Data
-export type Envelope<$Context extends Context, $Data = unknown, $Errors extends ReadonlyArray<Error> = ReadonlyArray<GraphQLError>> = 
-	& {
-			data?: $Data | null
-			extensions?: ObjMap
-		}
-	& (
-			$Context['config']['transport']['type'] extends 'http'
-			? { response: Response }
-			: {}  
-		)
-		// todo remove use of errors type variable. Rely only on $Config.
-	& (
-			$Errors extends []
-			? {}  
-			: IsEnvelopeWithoutErrors<$Context> extends true
-			? {}  
-			: {
-					errors?: ReadonlyArray<GraphQLError>
-				}
-		)
+export type Envelope<
+  $Context extends Context,
+  $Data = unknown,
+  $Errors extends ReadonlyArray<Error> = ReadonlyArray<GraphQLError>,
+> =
+  Simplify<
+    & {
+      data?: $Data | null
+        extensions?: ObjMap
+      }
+    & (
+        $Context['config']['transport']['type'] extends 'http'
+        ? { response: Response }
+        : {}
+      )
+      // todo remove use of errors type variable. Rely only on $Config.
+    & (
+        $Errors extends []
+        ? {}
+        : IsEnvelopeWithoutErrors<$Context> extends true
+        ? {}
+        : {
+            errors?: ReadonlyArray<GraphQLError>
+          }
+      )
+  >
 
 type ObjMap<T = unknown> = {
   [key: string]: T

src/documentBuilder/InferResult/__.test-d.ts

@@ -3,11 +3,13 @@ import type { db } from '../../../tests/_/schemas/db.js'
 import type { Schema } from '../../../tests/_/schemas/kitchen-sink/graffle/modules/schema.js'
 import type * as SelectionSets from '../../../tests/_/schemas/kitchen-sink/graffle/modules/selection-sets.js'
 import { assertEqual } from '../../lib/assert-equal.js'
-import type { SimplifyDeep } from '../../lib/prelude.js'
 import type { Registry } from '../../types/Schema/nodes/Scalar/helpers.js'
+import type { DocumentBuilder } from '../__.js'
 import type { InferResult } from './__.js'
 
-type $<$SelectionSet extends SelectionSets.Query> = SimplifyDeep<InferResult.OperationQuery<$SelectionSet, Schema>>
+type $<$SelectionSet extends SelectionSets.Query> = DocumentBuilder.SimplifyDeep<
+  InferResult.OperationQuery<$SelectionSet, Schema>
+>
 
 type $Registry = Registry.AddScalar<Registry.Empty, typeof DateScalar>
 

src/documentBuilder/Simplify.test-d.ts

@@ -0,0 +1,20 @@
+import { assertEqual } from '../lib/assert-equal.js'
+import type { SimplifyDeep, SimplifyDeepExcept } from './Simplify.js'
+
+// dprint-ignore
+{
+
+assertEqual<SimplifyDeep<{x:1|null}>									            , {x:1|null}>()
+assertEqual<SimplifyDeep<null | {x:1}>									          , null | {x:1}>()
+assertEqual<SimplifyDeep<null | {x?:1}>									          , null | {x?:1}>()
+assertEqual<SimplifyDeep<null | {x?:1|null}>									    , null | {x?:1|null}>()
+
+assertEqual<SimplifyDeepExcept<Date, null | Date>									, null | Date>()
+assertEqual<SimplifyDeepExcept<Date, {}>									        , {}>()
+assertEqual<SimplifyDeepExcept<Date, { a: Date }>					        , { a: Date }>()
+assertEqual<SimplifyDeepExcept<Date, { a: 1 }>						        , { a: 1 }>()
+assertEqual<SimplifyDeepExcept<Date, { a: { b: Date } }> 	        , { a: { b: Date } }>()
+assertEqual<SimplifyDeepExcept<Date, { a: { b: Date } }> 					, { a: { b: Date } }>()
+assertEqual<SimplifyDeepExcept<Date, { a: null | { b: Date } }> 	, { a: null | { b: Date } }>()
+
+}

src/documentBuilder/Simplify.ts

@@ -0,0 +1,18 @@
+import type { IntrospectionQuery } from 'graphql'
+import type { AnyAndUnknownToNever } from '../lib/prelude.js'
+
+export type SimplifyDeep<T> = SimplifyDeepExcept<never, T>
+
+// dprint-ignore
+export type SimplifyDeepExcept<$ExcludeType, $Type> =
+	$Type extends any ? // distribute execution over $Type members
+
+	// todo allow extensions to augment this list, with arbitrary types, not just custom scalars.
+	$Type extends AnyAndUnknownToNever<$ExcludeType> | IntrospectionQuery
+		? $Type
+		: {
+				[$Key in keyof $Type]:
+					& SimplifyDeepExcept<$ExcludeType, $Type[$Key]>
+					& ({} | null)
+			}
+	: never

src/documentBuilder/_.js

@@ -0,0 +1 @@
+export * from './Simplify.js'

src/documentBuilder/__.ts

@@ -0,0 +1 @@
+export * as DocumentBuilder from './_.js'

src/documentBuilder/requestMethods/document.ts

@@ -4,7 +4,7 @@ import { type HandleOutput } from '../../client/handleOutput.js'
 import type { InferResult } from '../../documentBuilder/InferResult/__.js'
 import type { Select } from '../../documentBuilder/Select/__.js'
 import type { Schema } from '../../entrypoints/schema.js'
-import type { IsTupleMultiple, SimplifyDeepExcept } from '../../lib/prelude.js'
+import type { IsTupleMultiple } from '../../lib/prelude.js'
 
 // dprint-ignore
 export type DocumentRunner<
@@ -18,17 +18,15 @@ export type DocumentRunner<
     const $Name extends string = $Params extends [] ? $$Name : $Params[0],
   >(...params: $Params) =>
     Promise<
-      SimplifyDeepExcept<
-        $$Context['scalars']['typesDecoded'],
-        HandleOutput<
+      & ({} | null)
+      & HandleOutput<
           $$Context,
           InferResult.Operation<
             Select.Document.GetOperation<$$Document, $Name>,
             $$Schema,
             Select.Document.GetOperationType<$$Document, $Name>
           >
         >
-      >
     >
 }
 

src/documentBuilder/requestMethods/requestMethods.test-d.ts

@@ -21,6 +21,7 @@ test(`query`, async () => {
   // scalar with required arguments
   expectTypeOf<Parameters<typeof graffle.query.stringWithRequiredArg>>().toEqualTypeOf<[input: Graffle.SelectionSets.Query.stringWithRequiredArg]>()
   // scalar custom
+  const result = await graffle.query.date()
   expectTypeOf(await graffle.query.date()).toMatchTypeOf<Date | null>()
   // scalar with explicit indicators
   // positive indicator

src/entrypoints/utilities-for-generated.ts

@@ -4,15 +4,8 @@ export type { ConfigGetOutputError, HandleOutput, HandleOutputGraffleRootField }
 export type { Config } from '../client/Settings/Config.js'
 export { type DocumentRunner } from '../documentBuilder/requestMethods/document.js'
 export * from '../documentBuilder/Select/__.js'
-export {
-  type AssertExtendsObject,
-  type Exact,
-  type ExactNonEmpty,
-  type SimplifyDeep,
-  type SimplifyDeepExcept,
-  type SimplifyExcept,
-  type UnionExpanded,
-} from '../lib/prelude.js'
+export { type SimplifyDeep, type SimplifyDeepExcept } from '../documentBuilder/Simplify.js'
+export { type AssertExtendsObject, type Exact, type ExactNonEmpty, type UnionExpanded } from '../lib/prelude.js'
 export { TypeFunction } from '../lib/type-function/__.js'
 export { type GlobalRegistry } from '../types/GlobalRegistry/GlobalRegistry.js'
 export { Schema } from '../types/Schema/__.js'

src/extensions/Introspection/Introspection.ts

@@ -2,7 +2,6 @@ import { getIntrospectionQuery, type IntrospectionQuery } from 'graphql'
 import type { Context } from '../../client/context.js'
 import type { HandleOutput } from '../../client/handleOutput.js'
 import { createBuilderExtension, createExtension } from '../../entrypoints/extensionkit.js'
-import type { SimplifyNullable } from '../../entrypoints/main.js'
 import type { Builder } from '../../lib/builder/__.js'
 import { type ConfigInput, createConfig } from './config.js'
 
@@ -73,7 +72,7 @@ interface BuilderExtension extends Builder.Extension {
 }
 
 interface BuilderExtension_<$Args extends Builder.Extension.Parameters<BuilderExtension>> {
-  introspect: () => Promise<SimplifyNullable<HandleOutput<$Args['context'], IntrospectionQuery>>>
+  introspect: () => Promise<(null | {}) & HandleOutput<$Args['context'], IntrospectionQuery>>
 }
 
 const knownPotentiallyUnsupportedFeatures = [`inputValueDeprecation`, `oneOf`] as const