Merge pull request graphql#3 from xuewei8910/wxue_question_mark

Added question mark token and corresponding behavior. Also updated the validation rule to include question mark.

src/__testUtils__/kitchenSinkQuery.ts

@@ -12,6 +12,8 @@ query queryName($foo: ComplexType, $site: Site = MOBILE) @onQuery {
       }
       field3!
       requiredField4: field4!
+      field5?
+      optionalField6: field6?
     }
     ... @skip(unless: $foo) {
       id

src/execution/execute.ts

@@ -29,7 +29,7 @@ import type {
 import { Kind } from '../language/kinds';
 
 import type { GraphQLSchema } from '../type/schema';
-import type {
+import {
   GraphQLObjectType,
   GraphQLOutputType,
   GraphQLLeafType,
@@ -39,6 +39,7 @@ import type {
   GraphQLResolveInfo,
   GraphQLTypeResolver,
   GraphQLList,
+  getNullableType,
 } from '../type/definition';
 import { assertValidSchema } from '../type/validate';
 import {
@@ -608,9 +609,15 @@ function resolveField(
     return;
   }
 
-  const returnType = fieldNodes[0].required // TODO: Need to update FieldNode
-    ? new GraphQLNonNull(fieldDef.type)
-    : fieldDef.type;
+  let returnType
+  if (fieldNodes[0].required === 'required' && !isNonNullType(fieldDef.type)) {
+    returnType = new GraphQLNonNull(fieldDef.type)
+  } else if(fieldNodes[0].required === 'optional' ){
+    returnType = getNullableType(fieldDef.type)
+  } else {
+    returnType = fieldDef.type
+  }
+
   const resolveFn = fieldDef.resolve ?? exeContext.fieldResolver;
 
   const info = buildResolveInfo(

src/index.ts

@@ -209,6 +209,7 @@ export {
   isTypeDefinitionNode,
   isTypeSystemExtensionNode,
   isTypeExtensionNode,
+  RequiredStatus,
 } from './language/index';
 
 export type {

src/language/__tests__/lexer-test.ts

@@ -161,16 +161,16 @@ describe('Lexer', () => {
   it('errors respect whitespace', () => {
     let caughtError;
     try {
-      lexOne(['', '', '    ?', ''].join('\n'));
+      lexOne(['', '', '    ~', ''].join('\n'));
     } catch (error) {
       caughtError = error;
     }
     expect(String(caughtError)).to.equal(dedent`
-      Syntax Error: Cannot parse the unexpected character "?".
+      Syntax Error: Cannot parse the unexpected character "~".
 
       GraphQL request:3:5
       2 |
-      3 |     ?
+      3 |     ~
         |     ^
       4 |
     `);
@@ -179,18 +179,18 @@ describe('Lexer', () => {
   it('updates line numbers in error for file context', () => {
     let caughtError;
     try {
-      const str = ['', '', '     ?', ''].join('\n');
+      const str = ['', '', '     ~', ''].join('\n');
       const source = new Source(str, 'foo.js', { line: 11, column: 12 });
       new Lexer(source).advance();
     } catch (error) {
       caughtError = error;
     }
     expect(String(caughtError)).to.equal(dedent`
-      Syntax Error: Cannot parse the unexpected character "?".
+      Syntax Error: Cannot parse the unexpected character "~".
 
       foo.js:13:6
       12 |
-      13 |      ?
+      13 |      ~
          |      ^
       14 |
     `);
@@ -199,16 +199,16 @@ describe('Lexer', () => {
   it('updates column numbers in error for file context', () => {
     let caughtError;
     try {
-      const source = new Source('?', 'foo.js', { line: 1, column: 5 });
+      const source = new Source('~', 'foo.js', { line: 1, column: 5 });
       new Lexer(source).advance();
     } catch (error) {
       caughtError = error;
     }
     expect(String(caughtError)).to.equal(dedent`
-      Syntax Error: Cannot parse the unexpected character "?".
+      Syntax Error: Cannot parse the unexpected character "~".
 
       foo.js:1:5
-      1 |     ?
+      1 |     ~
         |     ^
     `);
   });
@@ -819,8 +819,8 @@ describe('Lexer', () => {
       locations: [{ line: 1, column: 1 }],
     });
 
-    expectSyntaxError('?').to.deep.equal({
-      message: 'Syntax Error: Cannot parse the unexpected character "?".',
+    expectSyntaxError('~').to.deep.equal({
+      message: 'Syntax Error: Cannot parse the unexpected character "~".',
       locations: [{ line: 1, column: 1 }],
     });
 

src/language/__tests__/parser-test.ts

@@ -215,6 +215,16 @@ describe('Parser', () => {
     ).to.not.throw();
   });
 
+  it('parses optional field', () => {
+    expect(() =>
+      parse(`
+      query {
+        optionalField?
+      }
+    `),
+    ).to.not.throw();
+  });
+
   it('parses required with alias', () => {
     expect(() =>
       parse(`

src/language/__tests__/printer-test.ts

@@ -167,6 +167,8 @@ describe('Printer: Query document', () => {
             }
             field3!
             requiredField4: field4!
+            field5?
+            optionalField6: field6?
           }
           ... @skip(unless: $foo) {
             id

src/language/__tests__/visitor-test.ts

@@ -672,6 +672,16 @@ describe('Visitor', () => {
       ['enter', 'Name', 'name', 'Field'],
       ['leave', 'Name', 'name', 'Field'],
       ['leave', 'Field', 2, undefined],
+      ['enter', 'Field', 3, undefined],
+      ['enter', 'Name', 'name', 'Field'],
+      ['leave', 'Name', 'name', 'Field'],
+      ['leave', 'Field', 3, undefined],
+      ['enter', 'Field', 4, undefined],
+      ['enter', 'Name', 'alias', 'Field'],
+      ['leave', 'Name', 'alias', 'Field'],
+      ['enter', 'Name', 'name', 'Field'],
+      ['leave', 'Name', 'name', 'Field'],
+      ['leave', 'Field', 4, undefined],
       ['leave', 'SelectionSet', 'selectionSet', 'InlineFragment'],
       ['leave', 'InlineFragment', 1, undefined],
       ['enter', 'InlineFragment', 2, undefined],

src/language/ast.ts

@@ -285,7 +285,7 @@ export type SelectionSetNode = {
 
 export type SelectionNode = FieldNode | FragmentSpreadNode | InlineFragmentNode;
 
-type RequiredStatus = 'required' | 'optional' | 'unset';
+export type RequiredStatus = 'required' | 'optional' | 'unset';
 
 export type FieldNode = {
   readonly kind: 'Field';

src/language/index.ts

@@ -85,6 +85,7 @@ export type {
   UnionTypeExtensionNode,
   EnumTypeExtensionNode,
   InputObjectTypeExtensionNode,
+  RequiredStatus,
 } from './ast';
 
 export {

src/language/lexer.ts

@@ -204,6 +204,8 @@ function readToken(lexer: Lexer, prev: Token): Token {
       case 56: //  8
       case 57: //  9
         return readNumber(source, pos, code, line, col, prev);
+      case 63: //  ?
+        return new Token(TokenKind.QUESTION_MARK, pos, pos + 1, line, col, prev);
       case 65: //  A
       case 66: //  B
       case 67: //  C

src/language/parser.ts

@@ -393,9 +393,15 @@ export class Parser {
     } else {
       name = nameOrAlias;
     }
-    const required = this.expectOptionalToken(TokenKind.BANG)
-      ? 'required'
-      : 'unset';
+
+    let required;
+    if (this.expectOptionalToken(TokenKind.BANG)) {
+      required = 'required'
+    } else if (this.expectOptionalToken(TokenKind.QUESTION_MARK)) {
+      required = 'optional'
+    } else {
+      required = 'unset'
+    }
 
     // @ts-expect-error FIXME
     return this.node(start, {

src/language/printer.ts

@@ -56,7 +56,13 @@ const printDocASTReducer: any = {
 
   Field: {
     leave({ alias, name, arguments: args, directives, selectionSet, required }) {
-      const prefix = wrap('', alias, ': ') + name + (required ? '!' : '');
+      let prefix = wrap('', alias, ': ') + name;
+      if (required === 'required') {
+        prefix += '!'
+      } else if (required === 'optional') {
+        prefix += '?'
+      }
+
       let argsLine = prefix + wrap('(', join(args, ', '), ')');
 
       if (argsLine.length > MAX_LINE_LENGTH) {

src/language/tokenKind.ts

@@ -25,6 +25,7 @@ export const TokenKind = Object.freeze({
   STRING: 'String',
   BLOCK_STRING: 'BlockString',
   COMMENT: 'Comment',
+  QUESTION_MARK: '?',
 } as const);
 
 /**

src/validation/rules/OverlappingFieldsCanBeMergedRule.ts

@@ -10,15 +10,18 @@ import type {
   FieldNode,
   ArgumentNode,
   FragmentDefinitionNode,
+  RequiredStatus,
 } from '../../language/ast';
 import { Kind } from '../../language/kinds';
 import { print } from '../../language/printer';
 
-import type {
+import {
   GraphQLNamedType,
   GraphQLOutputType,
   GraphQLCompositeType,
   GraphQLField,
+  GraphQLNonNull,
+  getNullableType,
 } from '../../type/definition';
 import {
   getNamedType,
@@ -34,6 +37,7 @@ import { typeFromAST } from '../../utilities/typeFromAST';
 import type { Maybe } from '../../jsutils/Maybe';
 
 import type { ValidationContext } from '../ValidationContext';
+import { getIntrospectionQuery } from '../../../old_dts';
 
 function reasonMessage(reason: ConflictReasonMessage): string {
   if (Array.isArray(reason)) {
@@ -584,23 +588,8 @@ function findConflict(
     }
   }
 
-  // For now, fail the validation if the nullability status is different
-  if (node1.required === 'required') {
-    // if node1 is marked non-nullable,
-    if (node2.required !== 'required' && def2 && !isNonNullType(def2.type)) {
-      // if node2 is not marked non-nullable, and type is known and marked nullable
-      return [
-        [responseName, 'they have differing nullability status'],
-        [node1],
-        [node2],
-      ];
-    }
-  }
-
-  if (node2.required === 'required') {
-    // if node1 is marked non-nullable,
-    if (node1.required !== 'required' && def1 && !isNonNullType(def1.type)) {
-      // if node2 is not marked non-nullable, and type is known and marked nullable
+  if (node1.required !== node2.required) {
+    if (def1 && def2 && isNonNullWithRequiredStatus(def1.type, node1.required) !== isNonNullWithRequiredStatus(def2.type, node2.required)) {
       return [
         [responseName, 'they have differing nullability status'],
         [node1],
@@ -697,6 +686,18 @@ function doTypesConflict(
   return false;
 }
 
+function isNonNullWithRequiredStatus(
+  type: GraphQLOutputType,
+  required: RequiredStatus
+): boolean {
+  if (required === 'required') {
+    return true
+  } else if (required === 'optional') {
+    return false
+  }
+  return isNonNullType(type)
+}
+
 // Given a selection set, return the collection of fields (a mapping of response
 // name to field nodes and definitions) as well as a list of fragment names
 // referenced via fragment spreads.