Add FragmentOf helper

src/__tests__/selection.test-d.ts

@@ -9,7 +9,7 @@ import type {
   $tada,
   decorateFragmentDef,
   getFragmentsOfDocumentsRec,
-  FragmentDefDecoration,
+  makeFragmentDefDecoration,
 } from '../namespace';
 
 type schema = simpleSchema;
@@ -129,7 +129,7 @@ test('infers fragment spreads for fragment refs', () => {
   `>;
 
   type extraFragments = getFragmentsOfDocumentsRec<
-    [FragmentDefDecoration<decorateFragmentDef<fragment>>]
+    [makeFragmentDefDecoration<decorateFragmentDef<fragment>>]
   >;
 
   type actual = getDocumentType<query, schema, extraFragments>;

src/api.ts

@@ -1,4 +1,4 @@
-import type { DocumentNode } from '@0no-co/graphql.web';
+import type { DocumentNode, DefinitionNode } from '@0no-co/graphql.web';
 import { Kind, parse as _parse } from '@0no-co/graphql.web';
 
 import type {
@@ -9,10 +9,13 @@ import type {
 } from './introspection';
 
 import type {
-  decorateFragmentDef,
-  getFragmentsOfDocumentsRec,
   FragmentDefDecorationLike,
-  FragmentDefDecoration,
+  OperationDefDecorationLike,
+  getFragmentsOfDocumentsRec,
+  makeFragmentDefDecoration,
+  decorateFragmentDef,
+  makeFragmentRef,
+  $tada,
 } from './namespace';
 
 import type { getDocumentType } from './selection';
@@ -56,15 +59,20 @@ type getDocumentNode<
 
 function graphql<
   const In extends stringLiteral<In>,
-  const Fragments extends readonly [...FragmentDefDecorationLike[]],
+  const Fragments extends readonly [...OperationDefDecorationLike[]],
 >(
   input: In,
   fragments?: Fragments
 ): getDocumentNode<In, Schema, getFragmentsOfDocumentsRec<Fragments>> {
-  const definitions = new Set(_parse(input).definitions);
+  const definitions = _parse(input).definitions as DefinitionNode[];
+  const seen = new Set<unknown>();
   for (const document of fragments || []) {
-    for (const definition of document.definitions)
-      if (definition.kind === Kind.FRAGMENT_DEFINITION) definitions.add(definition);
+    for (const definition of document.definitions) {
+      if (definition.kind === Kind.FRAGMENT_DEFINITION && !seen.has(definition)) {
+        definitions.push(definition);
+        seen.add(definition);
+      }
+    }
   }
   return { kind: Kind.DOCUMENT, definitions: [...definitions] } as any;
 }
@@ -94,11 +102,22 @@ interface TadaDocumentNode<
   Decoration = never,
 > extends DocumentNode,
     DocumentDecoration<Result, Variables>,
-    FragmentDefDecoration<Decoration> {}
+    makeFragmentDefDecoration<Decoration> {}
 
-type ResultOf<T> = T extends DocumentDecoration<infer Result, infer _> ? Result : never;
+type ResultOf<Document> = Document extends DocumentDecoration<infer Result, infer _>
+  ? Result
+  : never;
+
+type VariablesOf<Document> = Document extends DocumentDecoration<infer _, infer Variables>
+  ? Variables
+  : never;
 
-type VariablesOf<T> = T extends DocumentDecoration<infer _, infer Variables> ? Variables : never;
+type FragmentOf<Document extends OperationDefDecorationLike> = Exclude<
+  Document[$tada.fragmentDef],
+  undefined
+> extends infer FragmentDef extends FragmentDefDecorationLike
+  ? makeFragmentRef<FragmentDef>
+  : never;
 
 export { parse, graphql };
-export type { setupSchema, TadaDocumentNode, ResultOf, VariablesOf };
+export type { setupSchema, TadaDocumentNode, ResultOf, VariablesOf, FragmentOf };

src/namespace.ts

@@ -20,6 +20,17 @@ declare namespace $tada {
   export type fragmentId = typeof fragmentId;
 }
 
+interface FragmentDefDecorationLike {
+  readonly [$tada.fragmentId]: symbol;
+  kind: Kind.FRAGMENT_DEFINITION;
+  name: any;
+  typeCondition: any;
+}
+
+interface OperationDefDecorationLike extends DocumentNode {
+  [$tada.fragmentDef]?: FragmentDefDecorationLike;
+}
+
 type decorateFragmentDef<Document extends DocumentNodeLike> = Document['definitions'][0] extends {
   kind: Kind.FRAGMENT_DEFINITION;
   name: any;
@@ -50,25 +61,24 @@ type getFragmentsOfDocumentsRec<Documents> = Documents extends readonly [
       getFragmentsOfDocumentsRec<Rest>
   : {};
 
-interface FragmentDefDecorationLike extends DocumentNode {
-  [$tada.fragmentDef]?: {
-    readonly [$tada.fragmentId]: symbol;
-    kind: Kind.FRAGMENT_DEFINITION;
-    name: any;
-    typeCondition: any;
+type makeFragmentRef<Definition extends FragmentDefDecorationLike> = {
+  [$tada.fragmentRefs]?: {
+    [Name in Definition['name']['value']]: Definition[$tada.fragmentId];
   };
-}
+};
 
-interface FragmentDefDecoration<Definition> {
-  [$tada.fragmentDef]?: Definition extends FragmentDefDecorationLike[$tada.fragmentDef]
+type makeFragmentDefDecoration<Definition> = {
+  [$tada.fragmentDef]?: Definition extends OperationDefDecorationLike[$tada.fragmentDef]
     ? Definition
     : never;
-}
+};
 
 export type {
   $tada,
   decorateFragmentDef,
   getFragmentsOfDocumentsRec,
+  makeFragmentDefDecoration,
+  makeFragmentRef,
   FragmentDefDecorationLike,
-  FragmentDefDecoration,
+  OperationDefDecorationLike,
 };

src/selection.ts

@@ -6,9 +6,9 @@ import type {
   NameNode,
 } from '@0no-co/graphql.web';
 
-import type { $tada } from './namespace';
 import type { obj, objValues } from './utils';
 import type { DocumentNodeLike } from './parser';
+import type { FragmentDefDecorationLike, $tada, makeFragmentRef } from './namespace';
 
 import type {
   IntrospectionField,
@@ -80,12 +80,8 @@ type getFragmentSelection<
   ? getSelection<Node['selectionSet']['selections'], Type, Introspection, Fragments>
   : Node extends { kind: Kind.FRAGMENT_SPREAD; name: any }
     ? Node['name']['value'] extends keyof Fragments
-      ? Fragments[Node['name']['value']] extends { readonly [$tada.fragmentId]: symbol }
-        ? {
-            [$tada.fragmentRefs]?: {
-              [Name in Node['name']['value']]: Fragments[Node['name']['value']][$tada.fragmentId];
-            };
-          }
+      ? Fragments[Node['name']['value']] extends FragmentDefDecorationLike
+        ? makeFragmentRef<Fragments[Node['name']['value']]>
         : getSelection<
             Fragments[Node['name']['value']]['selectionSet']['selections'],
             Type,