[WIP] Experimental support for semantic-non-null

src/__tests__/starWarsIntrospection-test.ts

@@ -42,6 +42,7 @@ describe('Star Wars Introspection Tests', () => {
             { name: '__TypeKind' },
             { name: '__Field' },
             { name: '__InputValue' },
+            { name: '__TypeNullability' },
             { name: '__EnumValue' },
             { name: '__Directive' },
             { name: '__DirectiveLocation' },

src/execution/__tests__/executor-test.ts

@@ -263,6 +263,7 @@ describe('Execute: Handles basic execution tasks', () => {
       'rootValue',
       'operation',
       'variableValues',
+      'errorPropagation',
     );
 
     const operation = document.definitions[0];
@@ -275,6 +276,7 @@ describe('Execute: Handles basic execution tasks', () => {
       schema,
       rootValue,
       operation,
+      errorPropagation: true,
     });
 
     const field = operation.selectionSet.selections[0];

src/execution/execute.ts

@@ -43,6 +43,7 @@
   isListType,
   isNonNullType,
   isObjectType,
+  isSemanticNonNullType,
 } from '../type/definition';
 import {
   SchemaMetaFieldDef,
@@ -115,6 +116,7 @@
   typeResolver: GraphQLTypeResolver<any, any>;
   subscribeFieldResolver: GraphQLFieldResolver<any, any>;
   errors: Array<GraphQLError>;
+  errorPropagation: boolean;
 }
 
 /**
@@ -152,6 +154,12 @@
   fieldResolver?: Maybe<GraphQLFieldResolver<any, any>>;
   typeResolver?: Maybe<GraphQLTypeResolver<any, any>>;
   subscribeFieldResolver?: Maybe<GraphQLFieldResolver<any, any>>;
+  /**
+   * Set to `false` to disable error propagation. Experimental.
+   *
+   * @experimental
+   */
+  errorPropagation?: boolean;
 }
 
 /**
@@ -286,6 +294,7 @@
     fieldResolver,
     typeResolver,
     subscribeFieldResolver,
+    errorPropagation,
   } = args;
 
   let operation: OperationDefinitionNode | undefined;
@@ -347,6 +356,7 @@
     typeResolver: typeResolver ?? defaultTypeResolver,
     subscribeFieldResolver: subscribeFieldResolver ?? defaultFieldResolver,
     errors: [],
+    errorPropagation: errorPropagation ?? true,
   };
 }
 
@@ -585,6 +595,7 @@
     rootValue: exeContext.rootValue,
     operation: exeContext.operation,
     variableValues: exeContext.variableValues,
+    errorPropagation: exeContext.errorPropagation,
   };
 }
 
@@ -595,7 +606,7 @@
 ): null {
   // If the field type is non-nullable, then it is resolved without any
   // protection from errors, however it still properly locates the error.
-  if (isNonNullType(returnType)) {
+  if (exeContext.errorPropagation && isNonNullType(returnType)) {
     throw error;
   }
 
@@ -658,6 +669,25 @@
     return completed;
   }
 
+  // If field type is SemanticNonNull, complete for inner type, and throw field error
+  // if result is null.
+  if (isSemanticNonNullType(returnType)) {
+    const completed = completeValue(
+      exeContext,
+      returnType.ofType,
+      fieldNodes,
+      info,
+      path,
+      result,
+    );
+    if (completed === null) {
+      throw new Error(
+        `Cannot return null for semantic-non-nullable field ${info.parentType.name}.${info.fieldName}.`,
+      );
+    }
+    return completed;
+  }
+
   // If result value is null or undefined then return null.
   if (result == null) {
     return null;

src/graphql.ts

@@ -66,6 +66,12 @@ export interface GraphQLArgs {
   operationName?: Maybe<string>;
   fieldResolver?: Maybe<GraphQLFieldResolver<any, any>>;
   typeResolver?: Maybe<GraphQLTypeResolver<any, any>>;
+  /**
+   * Set to `false` to disable error propagation. Experimental.
+   *
+   * @experimental
+   */
+  errorPropagation?: boolean;
 }
 
 export function graphql(args: GraphQLArgs): Promise<ExecutionResult> {
@@ -106,6 +112,7 @@ function graphqlImpl(args: GraphQLArgs): PromiseOrValue<ExecutionResult> {
     operationName,
     fieldResolver,
     typeResolver,
+    errorPropagation,
   } = args;
 
   // Validate Schema
@@ -138,5 +145,6 @@ function graphqlImpl(args: GraphQLArgs): PromiseOrValue<ExecutionResult> {
     operationName,
     fieldResolver,
     typeResolver,
+    errorPropagation,
   });
 }

src/index.ts

@@ -48,6 +48,7 @@ export {
   GraphQLInputObjectType,
   GraphQLList,
   GraphQLNonNull,
+  GraphQLSemanticNonNull,
   // Standard GraphQL Scalars
   specifiedScalarTypes,
   GraphQLInt,
@@ -74,6 +75,7 @@ export {
   __Schema,
   __Directive,
   __DirectiveLocation,
+  __TypeNullability,
   __Type,
   __Field,
   __InputValue,
@@ -95,6 +97,7 @@ export {
   isInputObjectType,
   isListType,
   isNonNullType,
+  isSemanticNonNullType,
   isInputType,
   isOutputType,
   isLeafType,
@@ -120,6 +123,7 @@ export {
   assertInputObjectType,
   assertListType,
   assertNonNullType,
+  assertSemanticNonNullType,
   assertInputType,
   assertOutputType,
   assertLeafType,
@@ -287,6 +291,7 @@ export type {
   NamedTypeNode,
   ListTypeNode,
   NonNullTypeNode,
+  SemanticNonNullTypeNode,
   TypeSystemDefinitionNode,
   SchemaDefinitionNode,
   OperationTypeDefinitionNode,
@@ -480,6 +485,7 @@ export type {
   IntrospectionNamedTypeRef,
   IntrospectionListTypeRef,
   IntrospectionNonNullTypeRef,
+  IntrospectionSemanticNonNullTypeRef,
   IntrospectionField,
   IntrospectionInputValue,
   IntrospectionEnumValue,

src/language/__tests__/parser-test.ts

@@ -631,6 +631,23 @@ describe('Parser', () => {
       });
     });
 
+    it('parses semantic-non-null types', () => {
+      const result = parseType('MyType*');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SEMANTIC_NON_NULL_TYPE,
+        loc: { start: 0, end: 7 },
+        type: {
+          kind: Kind.NAMED_TYPE,
+          loc: { start: 0, end: 6 },
+          name: {
+            kind: Kind.NAME,
+            loc: { start: 0, end: 6 },
+            value: 'MyType',
+          },
+        },
+      });
+    });
+
     it('parses nested types', () => {
       const result = parseType('[MyType!]');
       expectJSON(result).toDeepEqual({

src/language/__tests__/predicates-test.ts

@@ -92,6 +92,7 @@ describe('AST node predicates', () => {
       'NamedType',
       'ListType',
       'NonNullType',
+      'SemanticNonNullType',
     ]);
   });
 

src/language/ast.ts

@@ -161,6 +161,7 @@ export type ASTNode =
   | NamedTypeNode
   | ListTypeNode
   | NonNullTypeNode
+  | SemanticNonNullTypeNode
   | SchemaDefinitionNode
   | OperationTypeDefinitionNode
   | ScalarTypeDefinitionNode
@@ -235,6 +236,7 @@ export const QueryDocumentKeys: {
   NamedType: ['name'],
   ListType: ['type'],
   NonNullType: ['type'],
+  SemanticNonNullType: ['type'],
 
   SchemaDefinition: ['description', 'directives', 'operationTypes'],
   OperationTypeDefinition: ['type'],
@@ -520,7 +522,11 @@ export interface ConstDirectiveNode {
 
 /** Type Reference */
 
-export type TypeNode = NamedTypeNode | ListTypeNode | NonNullTypeNode;
+export type TypeNode =
+  | NamedTypeNode
+  | ListTypeNode
+  | NonNullTypeNode
+  | SemanticNonNullTypeNode;
 
 export interface NamedTypeNode {
   readonly kind: Kind.NAMED_TYPE;
@@ -540,6 +546,12 @@ export interface NonNullTypeNode {
   readonly type: NamedTypeNode | ListTypeNode;
 }
 
+export interface SemanticNonNullTypeNode {
+  readonly kind: Kind.SEMANTIC_NON_NULL_TYPE;
+  readonly loc?: Location;
+  readonly type: NamedTypeNode | ListTypeNode;
+}
+
 /** Type System Definition */
 
 export type TypeSystemDefinitionNode =

src/language/index.ts

@@ -67,6 +67,7 @@ export type {
   NamedTypeNode,
   ListTypeNode,
   NonNullTypeNode,
+  SemanticNonNullTypeNode,
   TypeSystemDefinitionNode,
   SchemaDefinitionNode,
   OperationTypeDefinitionNode,

src/language/kinds.ts

@@ -37,6 +37,7 @@ enum Kind {
   NAMED_TYPE = 'NamedType',
   LIST_TYPE = 'ListType',
   NON_NULL_TYPE = 'NonNullType',
+  SEMANTIC_NON_NULL_TYPE = 'SemanticNonNullType',
 
   /** Type System Definitions */
   SCHEMA_DEFINITION = 'SchemaDefinition',

src/language/lexer.ts

@@ -91,6 +91,7 @@ export class Lexer {
 export function isPunctuatorTokenKind(kind: TokenKind): boolean {
   return (
     kind === TokenKind.BANG ||
+    kind === TokenKind.ASTERISK ||
     kind === TokenKind.DOLLAR ||
     kind === TokenKind.AMP ||
     kind === TokenKind.PAREN_L ||
@@ -246,7 +247,7 @@ function readNextToken(lexer: Lexer, start: number): Token {
       //   - FloatValue
       //   - StringValue
       //
-      // Punctuator :: one of ! $ & ( ) ... : = @ [ ] { | }
+      // Punctuator :: one of ! $ & ( ) * ... : = @ [ ] { | }
       case 0x0021: // !
         return createToken(lexer, TokenKind.BANG, position, position + 1);
       case 0x0024: // $
@@ -257,6 +258,8 @@ function readNextToken(lexer: Lexer, start: number): Token {
         return createToken(lexer, TokenKind.PAREN_L, position, position + 1);
       case 0x0029: // )
         return createToken(lexer, TokenKind.PAREN_R, position, position + 1);
+      case 0x002a: // *
+        return createToken(lexer, TokenKind.ASTERISK, position, position + 1);
       case 0x002e: // .
         if (
           body.charCodeAt(position + 1) === 0x002e &&

src/language/parser.ts

@@ -50,6 +50,7 @@ import type {
   SchemaExtensionNode,
   SelectionNode,
   SelectionSetNode,
+  SemanticNonNullTypeNode,
   StringValueNode,
   Token,
   TypeNode,
@@ -740,6 +741,7 @@ export class Parser {
    *   - NamedType
    *   - ListType
    *   - NonNullType
+   *   - SemanticNonNullType
    */
   parseTypeReference(): TypeNode {
     const start = this._lexer.token;
@@ -761,6 +763,12 @@ export class Parser {
         type,
       });
     }
+    if (this.expectOptionalToken(TokenKind.ASTERISK)) {
+      return this.node<SemanticNonNullTypeNode>(start, {
+        kind: Kind.SEMANTIC_NON_NULL_TYPE,
+        type,
+      });
+    }
 
     return type;
   }

src/language/predicates.ts

@@ -67,7 +67,8 @@ export function isTypeNode(node: ASTNode): node is TypeNode {
   return (
     node.kind === Kind.NAMED_TYPE ||
     node.kind === Kind.LIST_TYPE ||
-    node.kind === Kind.NON_NULL_TYPE
+    node.kind === Kind.NON_NULL_TYPE ||
+    node.kind === Kind.SEMANTIC_NON_NULL_TYPE
   );
 }
 

src/language/printer.ts

@@ -131,6 +131,7 @@ const printDocASTReducer: ASTReducer<string> = {
   NamedType: { leave: ({ name }) => name },
   ListType: { leave: ({ type }) => '[' + type + ']' },
   NonNullType: { leave: ({ type }) => type + '!' },
+  SemanticNonNullType: { leave: ({ type }) => type + '*' },
 
   // Type System Definitions
 

src/language/tokenKind.ts

@@ -6,6 +6,7 @@ enum TokenKind {
   SOF = '<SOF>',
   EOF = '<EOF>',
   BANG = '!',
+  ASTERISK = '*',
   DOLLAR = '$',
   AMP = '&',
   PAREN_L = '(',