graphql-language-service/src/utils/__tests__/getASTNodeAtPosition-test.ts

The official, runtime independent Language Service for GraphQL

/**
 *  Copyright (c) 2021 GraphQL Contributors
 *  All rights reserved.
 *
 *  This source code is licensed under the license found in the
 *  LICENSE file in the root directory of this source tree.
 */

import { parse } from 'graphql';
import { Position } from '../Range';
import { getASTNodeAtPosition, pointToOffset } from '../getASTNodeAtPosition';

const doc = `
query A {
field
}

fragment B on B {
  b
}`;

const ast = parse(doc);

describe('getASTNodeAtPosition', () => {
  it('gets the node at the beginning', () => {
    const point = new Position(2, 0);
    const node = getASTNodeAtPosition(doc, ast, point);
    expect(node).not.toBeUndefined();
    if (node != null) {
      // @ts-ignore
      expect(node.name.value).toEqual('field');
    }
  });

  it('does not find the node before the beginning', () => {
    const point = new Position(0, 0);
    const node = getASTNodeAtPosition(doc, ast, point);
    expect(node).not.toBeUndefined();
    if (node != null) {
      expect(node.kind).toEqual('Document');
    }
  });

  it('gets the node at the end', () => {
    const point = new Position(2, 5);
    const node = getASTNodeAtPosition(doc, ast, point);
    expect(node).not.toBeUndefined();
    if (node != null) {
      // @ts-ignore
      expect(node.name.value).toEqual('field');
    }
  });

  it('does not find the node after the end', () => {
    const point = new Position(4, 0);
    const node = getASTNodeAtPosition(doc, ast, point);
    expect(node).not.toBeUndefined();
    if (node != null) {
      expect(node.kind).toEqual('Document');
    }
  });
});

describe('pointToOffset', () => {
  it('works for single lines', () => {
    const text = 'lorem';
    expect(pointToOffset(text, new Position(0, 2))).toEqual(2);
  });

  it('takes EOL into account', () => {
    const text = 'lorem\n';
    expect(pointToOffset(text, new Position(1, 0))).toEqual(text.length);
  });
});