export.js

import { test, testFilePath, SYNTAX_CASES, getTSParsers, testVersion } from '../utils';

import { RuleTester } from 'eslint';
import eslintPkg from 'eslint/package.json';
import semver from 'semver';

const ruleTester = new RuleTester();
const rule = require('rules/export');

ruleTester.run('export', rule, {
  valid: [].concat(
    test({ code: 'import "./malformed.js"' }),

    // default
    test({ code: 'var foo = "foo"; export default foo;' }),
    test({ code: 'export var foo = "foo"; export var bar = "bar";' }),
    test({ code: 'export var foo = "foo", bar = "bar";' }),
    test({ code: 'export var { foo, bar } = object;' }),
    test({ code: 'export var [ foo, bar ] = array;' }),
    test({ code: 'let foo; export { foo, foo as bar }' }),
    test({ code: 'let bar; export { bar }; export * from "./export-all"' }),
    test({ code: 'export * from "./export-all"' }),
    test({ code: 'export * from "./does-not-exist"' }),

    // #328: "export * from" does not export a default
    test({ code: 'export default foo; export * from "./bar"' }),

    ...SYNTAX_CASES,

    test({
      code: `
        import * as A from './named-export-collision/a';
        import * as B from './named-export-collision/b';

        export { A, B };
      `,
    }),
    testVersion('>= 6', () => ({
      code: `
        export * as A from './named-export-collision/a';
        export * as B from './named-export-collision/b';
      `,
      parserOptions: {
        ecmaVersion: 2020,
      },
    })) || [],
  ),

  invalid: [
    // multiple defaults
    // test({
    //   code: 'export default foo; export default bar',
    //   errors: ['Multiple default exports.', 'Multiple default exports.'],
    // }),
    // test({
    //   code: 'export default function foo() {}; ' +
    //              'export default function bar() {}',
    //   errors: ['Multiple default exports.', 'Multiple default exports.'],
    // }),

    // test({
    //   code: 'export function foo() {}; ' +
    //              'export { bar as foo }',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export {foo}; export {foo};',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export {foo}; export {bar as foo};',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export var foo = "foo"; export var foo = "bar";',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export var foo = "foo", foo = "bar";',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    test({
      code: 'let foo; export { foo }; export * from "./export-all"',
      errors: ['Multiple exports of name \'foo\'.',
        'Multiple exports of name \'foo\'.'],
    }),
    // test({ code: 'export * from "./default-export"'
    //      , errors: [{ message: 'No named exports found in module ' +
    //                            '\'./default-export\'.'
    //                 , type: 'Literal' }] }),

    // note: Espree bump to Acorn 4+ changed this test's error message.
    //       `npm up` first if it's failing.
    test({
      code: 'export * from "./malformed.js"',
      errors: [{
        message: "Parse errors in imported module './malformed.js': 'return' outside of function (1:1)",
        type: 'Literal',
      }],
    }),

    // test({
    //   code: 'export var { foo, bar } = object; export var foo = "bar"',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export var { bar: { foo } } = object; export var foo = "bar"',
    //   errors: ['Parsing error: Duplicate export \'foo\''],
    // }),
    // test({
    //   code: 'export var [ foo, bar ] = array; export var bar = "baz"',
    //   errors: ['Parsing error: Duplicate export \'bar\''],
    // }),
    // test({
    //   code: 'export var [ foo, /*sparse*/, { bar } ] = array; export var bar = "baz"',
    //   errors: ['Parsing error: Duplicate export \'bar\''],
    // }),


    // #328: "export * from" does not export a default
    test({
      code: 'export * from "./default-export"',
      errors: [`No named exports found in module './default-export'.`],
    }),
  ],
});


context('TypeScript', function () {
  getTSParsers().forEach((parser) => {
    const parserConfig = {
      parser,
      settings: {
        'import/parsers': { [parser]: ['.ts'] },
        'import/resolver': { 'eslint-import-resolver-typescript': true },
      },
    };

    ruleTester.run('export', rule, {
      valid: [
        // type/value name clash
        test(Object.assign({
          code: `
            export const Foo = 1;
            export type Foo = number;
          `,
        }, parserConfig)),
        test(Object.assign({
          code: `
            export const Foo = 1;
            export interface Foo {}
          `,
        }, parserConfig)),

        test(Object.assign({
          code: `
            export function fff(a: string);
            export function fff(a: number);
          `,
        }, parserConfig)),

        test(Object.assign({
          code: `
            export function fff(a: string);
            export function fff(a: number);
            export function fff(a: string|number) {};
          `,
        }, parserConfig)),

        // namespace
        test(Object.assign({
          code: `
            export const Bar = 1;
            export namespace Foo {
              export const Bar = 1;
            }
          `,
        }, parserConfig)),
        test(Object.assign({
          code: `
            export type Bar = string;
            export namespace Foo {
              export type Bar = string;
            }
          `,
        }, parserConfig)),
        test(Object.assign({
          code: `
            export const Bar = 1;
            export type Bar = string;
            export namespace Foo {
              export const Bar = 1;
              export type Bar = string;
            }
          `,
        }, parserConfig)),
        test(Object.assign({
          code: `
            export namespace Foo {
              export const Foo = 1;
              export namespace Bar {
                export const Foo = 2;
              }
              export namespace Baz {
                export const Foo = 3;
              }
            }
          `,
        }, parserConfig)),
        test(Object.assign({
          code: 'export * from "./file1.ts"',
          filename: testFilePath('typescript-d-ts/file-2.ts'),
        }, parserConfig)),

        ...(semver.satisfies(eslintPkg.version, '< 6') ? [] : [
          test({
            code: `
              export * as A from './named-export-collision/a';
              export * as B from './named-export-collision/b';
            `,
            parser,
          }),
        ]),

        // Exports in ambient modules
        test(Object.assign({
          code: `
            declare module "a" {
              const Foo = 1;
              export {Foo as default};
            }
            declare module "b" {
              const Bar = 2;
              export {Bar as default};
            }
          `,
        }, parserConfig)),
        test(Object.assign({
          code: `
            declare module "a" {
              const Foo = 1;
              export {Foo as default};
            }
            const Bar = 2;
            export {Bar as default};
          `,
        }, parserConfig)),

        ...(semver.satisfies(process.version, '< 8') && semver.satisfies(eslintPkg.version, '< 6') ? [] : test({
          ...parserConfig,
          code: `
            export * from './module';
          `,
          filename: testFilePath('export-star-4/index.js'),
          settings: {
            ...parserConfig.settings,
            'import/extensions': ['.js', '.ts', '.jsx'],
          },
        })),
      ],
      invalid: [
        // type/value name clash
        test(Object.assign({
          code: `
            export type Foo = string;
            export type Foo = number;
          `,
          errors: [
            {
              message: `Multiple exports of name 'Foo'.`,
              line: 2,
            },
            {
              message: `Multiple exports of name 'Foo'.`,
              line: 3,
            },
          ],
        }, parserConfig)),

        // namespace
        test(Object.assign({
          code: `
            export const a = 1
            export namespace Foo {
              export const a = 2;
              export const a = 3;
            }
          `,
          errors: [
            {
              message: `Multiple exports of name 'a'.`,
              line: 4,
            },
            {
              message: `Multiple exports of name 'a'.`,
              line: 5,
            },
          ],
        }, parserConfig)),
        test(Object.assign({
          code: `
            declare module 'foo' {
              const Foo = 1;
              export default Foo;
              export default Foo;
            }
          `,
          errors: [
            {
              message: 'Multiple default exports.',
              line: 4,
            },
            {
              message: 'Multiple default exports.',
              line: 5,
            },
          ],
        }, parserConfig)),
        test(Object.assign({
          code: `
            export namespace Foo {
              export namespace Bar {
                export const Foo = 1;
                export const Foo = 2;
              }
              export namespace Baz {
                export const Bar = 3;
                export const Bar = 4;
              }
            }
          `,
          errors: [
            {
              message: `Multiple exports of name 'Foo'.`,
              line: 4,
            },
            {
              message: `Multiple exports of name 'Foo'.`,
              line: 5,
            },
            {
              message: `Multiple exports of name 'Bar'.`,
              line: 8,
            },
            {
              message: `Multiple exports of name 'Bar'.`,
              line: 9,
            },
          ],
        }, parserConfig)),

        // Exports in ambient modules
        test(Object.assign({
          code: `
            declare module "a" {
              const Foo = 1;
              export {Foo as default};
            }
            const Bar = 2;
            export {Bar as default};
            const Baz = 3;
            export {Baz as default};
          `,
          errors: [
            {
              message: 'Multiple default exports.',
              line: 7,
            },
            {
              message: 'Multiple default exports.',
              line: 9,
            },
          ],
        }, parserConfig)),
      ],
    });
  });
});