Schema Coordinates

src/index.ts

@@ -236,6 +236,7 @@ export {
   parseValue,
   parseConstValue,
   parseType,
+  parseSchemaCoordinate,
   // Print
   print,
   // Visit
@@ -255,6 +256,7 @@ export {
   isTypeDefinitionNode,
   isTypeSystemExtensionNode,
   isTypeExtensionNode,
+  isSchemaCoordinateNode,
 } from './language/index.js';
 
 export type {
@@ -327,6 +329,7 @@ export type {
   UnionTypeExtensionNode,
   EnumTypeExtensionNode,
   InputObjectTypeExtensionNode,
+  SchemaCoordinateNode,
 } from './language/index.js';
 
 // Execute GraphQL queries.
@@ -496,6 +499,8 @@ export {
   findBreakingChanges,
   findDangerousChanges,
   findSchemaChanges,
+  resolveSchemaCoordinate,
+  resolveASTSchemaCoordinate,
 } from './utilities/index.js';
 
 export type {
@@ -526,4 +531,5 @@ export type {
   SafeChange,
   DangerousChange,
   TypedQueryDocumentNode,
+  ResolvedSchemaElement,
 } from './utilities/index.js';

src/language/__tests__/lexer-test.ts

@@ -166,8 +166,8 @@ describe('Lexer', () => {
   });
 
   it('reports unexpected characters', () => {
-    expectSyntaxError('.').to.deep.equal({
-      message: 'Syntax Error: Unexpected character: ".".',
+    expectSyntaxError('^').to.deep.equal({
+      message: 'Syntax Error: Unexpected character: "^".',
       locations: [{ line: 1, column: 1 }],
     });
   });
@@ -965,6 +965,13 @@ describe('Lexer', () => {
       value: undefined,
     });
 
+    expect(lexOne('.')).to.contain({
+      kind: TokenKind.DOT,
+      start: 0,
+      end: 1,
+      value: undefined,
+    });
+
     expect(lexOne('...')).to.contain({
       kind: TokenKind.SPREAD,
       start: 0,

src/language/__tests__/parser-test.ts

@@ -11,7 +11,13 @@ import { kitchenSinkQuery } from '../../__testUtils__/kitchenSinkQuery.js';
 import { inspect } from '../../jsutils/inspect.js';
 
 import { Kind } from '../kinds.js';
-import { parse, parseConstValue, parseType, parseValue } from '../parser.js';
+import {
+  parse,
+  parseConstValue,
+  parseSchemaCoordinate,
+  parseType,
+  parseValue,
+} from '../parser.js';
 import { Source } from '../source.js';
 import { TokenKind } from '../tokenKind.js';
 
@@ -679,4 +685,129 @@ describe('Parser', () => {
       });
     });
   });
+
+  describe('parseSchemaCoordinate', () => {
+    it('parses Name', () => {
+      const result = parseSchemaCoordinate('MyType');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SCHEMA_COORDINATE,
+        loc: { start: 0, end: 6 },
+        ofDirective: false,
+        name: {
+          kind: Kind.NAME,
+          loc: { start: 0, end: 6 },
+          value: 'MyType',
+        },
+        memberName: undefined,
+        argumentName: undefined,
+      });
+    });
+
+    it('parses Name . Name', () => {
+      const result = parseSchemaCoordinate('MyType.field');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SCHEMA_COORDINATE,
+        loc: { start: 0, end: 12 },
+        ofDirective: false,
+        name: {
+          kind: Kind.NAME,
+          loc: { start: 0, end: 6 },
+          value: 'MyType',
+        },
+        memberName: {
+          kind: Kind.NAME,
+          loc: { start: 7, end: 12 },
+          value: 'field',
+        },
+        argumentName: undefined,
+      });
+    });
+
+    it('rejects Name . Name . Name', () => {
+      expect(() => parseSchemaCoordinate('MyType.field.deep'))
+        .to.throw()
+        .to.deep.include({
+          message: 'Syntax Error: Expected <EOF>, found ".".',
+          locations: [{ line: 1, column: 13 }],
+        });
+    });
+
+    it('parses Name . Name ( Name : )', () => {
+      const result = parseSchemaCoordinate('MyType.field(arg:)');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SCHEMA_COORDINATE,
+        loc: { start: 0, end: 18 },
+        ofDirective: false,
+        name: {
+          kind: Kind.NAME,
+          loc: { start: 0, end: 6 },
+          value: 'MyType',
+        },
+        memberName: {
+          kind: Kind.NAME,
+          loc: { start: 7, end: 12 },
+          value: 'field',
+        },
+        argumentName: {
+          kind: Kind.NAME,
+          loc: { start: 13, end: 16 },
+          value: 'arg',
+        },
+      });
+    });
+
+    it('rejects Name . Name ( Name : Name )', () => {
+      expect(() => parseSchemaCoordinate('MyType.field(arg: value)'))
+        .to.throw()
+        .to.deep.include({
+          message: 'Syntax Error: Expected ")", found Name "value".',
+          locations: [{ line: 1, column: 19 }],
+        });
+    });
+
+    it('parses @ Name', () => {
+      const result = parseSchemaCoordinate('@myDirective');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SCHEMA_COORDINATE,
+        loc: { start: 0, end: 12 },
+        ofDirective: true,
+        name: {
+          kind: Kind.NAME,
+          loc: { start: 1, end: 12 },
+          value: 'myDirective',
+        },
+        memberName: undefined,
+        argumentName: undefined,
+      });
+    });
+
+    it('parses @ Name ( Name : )', () => {
+      const result = parseSchemaCoordinate('@myDirective(arg:)');
+      expectJSON(result).toDeepEqual({
+        kind: Kind.SCHEMA_COORDINATE,
+        loc: { start: 0, end: 18 },
+        ofDirective: true,
+        name: {
+          kind: Kind.NAME,
+          loc: { start: 1, end: 12 },
+          value: 'myDirective',
+        },
+        memberName: undefined,
+        argumentName: {
+          kind: Kind.NAME,
+          loc: { start: 13, end: 16 },
+          value: 'arg',
+        },
+      });
+    });
+
+    it('rejects @ Name . Name', () => {
+      expect(() => parseSchemaCoordinate('@myDirective.field'))
+        .to.throw()
+        .to.deep.include({
+          message: 'Syntax Error: Expected <EOF>, found ".".',
+          locations: [{ line: 1, column: 13 }],
+        });
+    });
+  });
 });

src/language/__tests__/predicates-test.ts

@@ -8,6 +8,7 @@ import {
   isConstValueNode,
   isDefinitionNode,
   isExecutableDefinitionNode,
+  isSchemaCoordinateNode,
   isSelectionNode,
   isTypeDefinitionNode,
   isTypeExtensionNode,
@@ -141,4 +142,10 @@ describe('AST node predicates', () => {
       'UnionTypeExtension',
     ]);
   });
+
+  it('isSchemaCoordinateNode', () => {
+    expect(filterNodes(isSchemaCoordinateNode)).to.deep.equal([
+      'SchemaCoordinate',
+    ]);
+  });
 });

src/language/__tests__/printer-test.ts

@@ -5,7 +5,7 @@ import { dedent, dedentString } from '../../__testUtils__/dedent.js';
 import { kitchenSinkQuery } from '../../__testUtils__/kitchenSinkQuery.js';
 
 import { Kind } from '../kinds.js';
-import { parse } from '../parser.js';
+import { parse, parseSchemaCoordinate } from '../parser.js';
 import { print } from '../printer.js';
 
 describe('Printer: Query document', () => {
@@ -299,4 +299,18 @@ describe('Printer: Query document', () => {
     `),
     );
   });
+
+  it('prints schema coordinates', () => {
+    expect(print(parseSchemaCoordinate('  Name  '))).to.equal('Name');
+    expect(print(parseSchemaCoordinate('  Name . field '))).to.equal(
+      'Name.field',
+    );
+    expect(print(parseSchemaCoordinate('  Name . field ( arg: )'))).to.equal(
+      'Name.field(arg:)',
+    );
+    expect(print(parseSchemaCoordinate(' @ name  '))).to.equal('@name');
+    expect(print(parseSchemaCoordinate(' @ name (arg:) '))).to.equal(
+      '@name(arg:)',
+    );
+  });
 });

src/language/ast.ts

@@ -181,7 +181,8 @@ export type ASTNode =
   | InterfaceTypeExtensionNode
   | UnionTypeExtensionNode
   | EnumTypeExtensionNode
-  | InputObjectTypeExtensionNode;
+  | InputObjectTypeExtensionNode
+  | SchemaCoordinateNode;
 
 /**
  * Utility type listing all nodes indexed by their kind.
@@ -287,6 +288,7 @@ export const QueryDocumentKeys: {
   UnionTypeExtension: ['name', 'directives', 'types'],
   EnumTypeExtension: ['name', 'directives', 'values'],
   InputObjectTypeExtension: ['name', 'directives', 'fields'],
+  SchemaCoordinate: ['name', 'memberName', 'argumentName'],
 };
 
 const kindValues = new Set<string>(Object.keys(QueryDocumentKeys));
@@ -762,3 +764,14 @@ export interface InputObjectTypeExtensionNode {
   readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
   readonly fields?: ReadonlyArray<InputValueDefinitionNode> | undefined;
 }
+
+// Schema Coordinates
+
+export interface SchemaCoordinateNode {
+  readonly kind: 'SchemaCoordinate';
+  readonly loc?: Location;
+  readonly ofDirective: boolean;
+  readonly name: NameNode;
+  readonly memberName?: NameNode | undefined;
+  readonly argumentName?: NameNode | undefined;
+}

src/language/index.ts

@@ -13,7 +13,13 @@ export { TokenKind } from './tokenKind.js';
 
 export { Lexer } from './lexer.js';
 
-export { parse, parseValue, parseConstValue, parseType } from './parser.js';
+export {
+  parse,
+  parseValue,
+  parseConstValue,
+  parseType,
+  parseSchemaCoordinate,
+} from './parser.js';
 export type { ParseOptions } from './parser.js';
 
 export { print } from './printer.js';
@@ -90,6 +96,7 @@ export type {
   UnionTypeExtensionNode,
   EnumTypeExtensionNode,
   InputObjectTypeExtensionNode,
+  SchemaCoordinateNode,
 } from './ast.js';
 
 export {
@@ -103,6 +110,7 @@ export {
   isTypeDefinitionNode,
   isTypeSystemExtensionNode,
   isTypeExtensionNode,
+  isSchemaCoordinateNode,
 } from './predicates.js';
 
 export { DirectiveLocation } from './directiveLocation.js';

src/language/kinds_.ts

@@ -108,3 +108,7 @@ export const ENUM_TYPE_EXTENSION = 'EnumTypeExtension';
 export type ENUM_TYPE_EXTENSION = typeof ENUM_TYPE_EXTENSION;
 export const INPUT_OBJECT_TYPE_EXTENSION = 'InputObjectTypeExtension';
 export type INPUT_OBJECT_TYPE_EXTENSION = typeof INPUT_OBJECT_TYPE_EXTENSION;
+
+/** Schema Coordinates */
+export const SCHEMA_COORDINATE = 'SchemaCoordinate';
+export type SCHEMA_COORDINATE = typeof SCHEMA_COORDINATE;