Test suite doesnt work with dependencies

[seanaye]

Expected Behavior

Simple jest tests should work when there are project dependencies that use ESM syntax.

Actual Behavior

If any added dependency has ESM exports, jest tests will fail and complain about unexpected tokens

FAIL src/utils.test.ts
  ● Test suite failed to run

    Jest encountered an unexpected token

    This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

    By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".

    Here's what you can do:
     • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.
     • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
     • If you need a custom transformation specify a "transform" option in your config.
     • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.

    You'll find more details and examples of these config options in the docs:
    https://jestjs.io/docs/en/configuration.html

    Details:

    /Users/seanaye/dev/coparse/filesystem/node_modules/idb/with-async-ittr.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export * from './build/esm/index.js';
                                                                                             ^^^^^^

    SyntaxError: Unexpected token 'export'

      1 | import { FileHandle, FileSource, FileSystemFile, LegacyFile } from "./file";
    > 2 | import { DBSchema, IDBPDatabase, openDB } from "idb/with-async-ittr.js";

I have tried all of the things suggested by the error message but nothing works.

Steps to Reproduce the Problem

1. Add a project dependency with ESM exports in my case this is idb
2. Try to run a jest test in which this dependency is imported
3. Test failure

Specifications

• Version: 0.4.2
• Platform: MacOS, Node 16.1

[laustdeleuran]

+1

SyntaxError: Cannot use import statement outside a module

Steps to reproduce

1. Clone this repo.
2. Add dependencies: yarn add rehype-stringify remark-gfm remark-parse remark-rehype unified
3. Add utility function and corresponding test:

   // src/format.ts
   import rehypeStringify from "rehype-stringify";
   import remarkGfm from "remark-gfm";
   import remarkParse from "remark-parse";
   import remarkRehype from "remark-rehype";
   import { unified } from "unified";
   
   export const format = (markdown: string) =>
     unified()
       .use(remarkParse)
       .use(remarkGfm)
       .use(remarkRehype)
       .use(rehypeStringify)
       .processSync(markdown)
       .toString();

   // src/format.test.ts
   import { format } from "./format";
   
   describe("format", () => {
     it("should parse markdown", () => {
       expect(format("# Headline")).toBe("<h1>Headline</h1>");
     });
   });

4. Run yarn test and see error output:

    FAIL  src/format.test.ts
     ● Test suite failed to run
   
       Jest encountered an unexpected token
   
       This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
   
       By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
   
       Here's what you can do:
        • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.
        • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
        • If you need a custom transformation specify a "transform" option in your config.
        • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
   
       You'll find more details and examples of these config options in the docs:
       https://jestjs.io/docs/en/configuration.html
   
       Details:
   
       /typescript-boilerplate/node_modules/remark-gfm/index.js:6
       import {gfm} from 'micromark-extension-gfm'
       ^^^^^^
   
       SyntaxError: Cannot use import statement outside a module
   
       > 1 | import remarkGfm from "remark-gfm";
           | ^
         2 | import remarkParse from "remark-parse";
         3 | import remarkRehype from "remark-rehype";
         4 | import { unified } from "unified";
   
         at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1350:14)
         at Object.<anonymous> (src/format.ts:1:1)
   
   Test Suites: 1 failed, 1 passed, 2 total
   

5. Weep.