Add SchemaCoordinateLexer test

Author: magicmark

src/language/__tests__/lexer-test.ts

@@ -9,7 +9,11 @@ import { inspect } from '../../jsutils/inspect.js';
 import { GraphQLError } from '../../error/GraphQLError.js';
 
 import type { Token } from '../ast.js';
-import { isPunctuatorTokenKind, Lexer } from '../lexer.js';
+import {
+  isPunctuatorTokenKind,
+  Lexer,
+  SchemaCoordinateLexer,
+} from '../lexer.js';
 import { Source } from '../source.js';
 import { TokenKind } from '../tokenKind.js';
 
@@ -1189,6 +1193,33 @@ describe('Lexer', () => {
   });
 });
 
+describe('SchemaCoordinateLexer', () => {
+  it('can be stringified', () => {
+    const lexer = new SchemaCoordinateLexer(new Source('Name.field'));
+    expect(Object.prototype.toString.call(lexer)).to.equal(
+      '[object SchemaCoordinateLexer]',
+    );
+  });
+
+  it('tracks a schema coordinate', () => {
+    const lexer = new SchemaCoordinateLexer(new Source('Name.field'));
+    expect(lexer.advance()).to.contain({
+      kind: TokenKind.NAME,
+      start: 0,
+      end: 4,
+      value: 'Name',
+    });
+  });
+
+  it('forbids ignored tokens', () => {
+    const lexer = new SchemaCoordinateLexer(new Source('\nName.field'));
+    expectToThrowJSON(() => lexer.advance()).to.deep.equal({
+      message: 'Syntax Error: Invalid character: U+000A.',
+      locations: [{ line: 1, column: 1 }],
+    });
+  });
+});
+
 describe('isPunctuatorTokenKind', () => {
   function isPunctuatorToken(text: string) {
     return isPunctuatorTokenKind(lexOne(text).kind);