migrate-default-exports-to-named-exports.test.js

import { describe, expect, it } from 'vitest';
import jscodeshift from 'jscodeshift';
import migrateDefaultExportsToNamedImports from './migrate-default-exports-to-named-exports';

const testData = {
  fileWithDefaultExport: {
    before: `
      const SomeOtherVar = 'should be unchanged';
      const MyExport = 'this should change';
      function MyFunctionExport() { return 'this should change' }

      export default MyExport;
      export default MyFunctionExport;
    `,
    after: `
      const SomeOtherVar = 'should be unchanged';
      export const MyExport = 'this should change';
      export function MyFunctionExport() { return 'this should change' }
    `,
  },
  fileImportingDefaultExport: {
    before: `
      // should leave these unchanged
      import styled from 'styled-components/native';
      import avatar from './avatar.png';
      import avatar2 from './avatar.jpg';
      import avatar3 from './avatar.jpeg';
      import README from './avatar.md';
      
      // should update these
      import SomeDefaultExport from './relative/import';
      import AnotherDefaultExport, { NamedExport } from './relative/import';
    `,
    after: `
      // should leave these unchanged
      import styled from 'styled-components/native';
      import avatar from './avatar.png';
      import avatar2 from './avatar.jpg';
      import avatar3 from './avatar.jpeg';
      import README from './avatar.md';
      
      // should update these
      import { SomeDefaultExport } from './relative/import';
      import { AnotherDefaultExport, NamedExport } from './relative/import';
    `,
  },
  fileWithExportDefaultAs: {
    before: `
      export { default as MyExport } from './some/path';
      export type { TypeOne, TypeTwo } from './some/path'; // should delete this line
      export { default as AnotherExport } from './some/other/path';
    `,
    after: `
      export * from './some/path';
      export * from './some/other/path';
    `,
  },
  fileWithADefaultExportThatIsAlreadyANamedExport: {
    before: `
      export const MyConst = () => 'should remain unchanged';
      export function MyFunction() { return 'should remain unchanged' }
      export class MyClass {}
      
      export default MyConst;
      export default MyFunction;
      export default MyClass;
    `,
    after: `
      export const MyConst = () => 'should remain unchanged';
      export function MyFunction() { return 'should remain unchanged' }
      export class MyClass {}
    `
  },
  fileWithInlineDefaultExport: {
    before: `export default () => "hello";`,
    // assuming the name of the file is FileName.js
    after: `export const FileName = () => "hello";`,
  },
  fileWithInlineFunctionExport: {
    before: `export default function hello() { return "hello" }`,
    after: `export function hello() { return "hello" }`,
  },
  fileWithInlineClassExport: {
    before: `export default class Hello extends Object {}`,
    after: `export class Hello extends Object {}`,
  },
};

describe('migrate-default-exports-to-named-exports', () => {
  const runMigration = (source) =>
    migrateDefaultExportsToNamedImports({ source, path: './some/FileName.js' }, { jscodeshift: jscodeshift });

  it('migrates files that contain a default export to use named exports instead', () => {
    const { before, after } = testData.fileWithDefaultExport;
    expect(runMigration(before)).to.equal(after);
  });

  it('migrates files that use a local default export to use the named export instead', () => {
    const { before, after } = testData.fileImportingDefaultExport;
    expect(runMigration(before)).to.equal(after);
  });

  it('migrates files with export-default-as to use export-* instead', () => {
    const { before, after } = testData.fileWithExportDefaultAs;
    expect(runMigration(before)).to.equal(after);
  });

  it('migrates inline default exports', () => {
    const { before, after } = testData.fileWithInlineDefaultExport;
    expect(runMigration(before)).to.equal(after);
  });

  it('migrates inline default function exports', () => {
    const { before, after } = testData.fileWithInlineFunctionExport;
    expect(runMigration(before)).to.equal(after);
  });

  it('migrates inline default class exports', () => {
    const { before, after } = testData.fileWithInlineClassExport;
    expect(runMigration(before)).to.equal(after);
  });

  it('does not add double export keywords to declarations that already have a default export AND a name export', () => {
    const { before, after } = testData.fileWithADefaultExportThatIsAlreadyANamedExport;
    expect(runMigration(before)).to.equal(after);
  });
});