Requires Node16/NodeNext?

[mrwizard82d1]

I was trying to work through the "Just the API, please" section of the Setup document.

When I entered the line import Result, { err, map, ok, string } from 'type-script/result';, Webstorm reports that it cannot find the module 'true-myth/result. I confirmed that I had installed true-myth. Additionally, I noticed that Webstore identified the module as coming from 'node_modules/true-myth/dist/public/result.d.ts' which seemed to be correct. (I had created the Webstorm project by executing yarn create react-app --template typescript learn-true-myth`)

The same error occurred in a different environment using an environment with ts-node installed. Finally, I executed the code tsc result-functional.ts | node in my shell and saw the same error.

When I changed the import statement to import Result, { err, map, ok, string } from 'type-script/dist/public/result'; Webstorm reported no error.

What is the correct way to import items from true-myth?

P. S. I'm running on a 64-bit installation of Windows-10. My shell is a Git bash shell running zsh in WSL2.

[mrwizard82d1]

Here is the output of piping tsc to node:

λ tsc result-functional.ts | node
[stdin]:1
result-functional.ts(1,48): error TS2307: Cannot find module 'true-myth/result' or its corresponding type declarations.
^

SyntaxError: Unexpected token ':'
←[90m at new Script (node:vm:101:7)←[39m
←[90m at createScript (node:vm:258:10)←[39m
←[90m at Object.runInThisContext (node:vm:306:10)←[39m
←[90m at node:internal/process/execution:76:19←[39m
at [stdin]-wrapper:6:22
←[90m at evalScript (node:internal/process/execution:75:60)←[39m
←[90m at node:internal/main/eval_stdin:29:5←[39m
←[90m at Socket. (node:internal/process/execution:213:5)←[39m
←[90m at Socket.emit (node:events:549:35)←[39m
←[90m at endReadableNT (node:internal/streams/readable:1359:12)←[39m

Node.js v18.4.0

[github-actions[bot]]

Thanks so much for filing this issue, and for using True Myth!
This repo is actively supported, but maintainers are busy. One of us will be by soon to give it a look. If you don't hear from us within a week, feel free to give us a gentle nudge.

[mrwizard82d1]

I seem to encounter similar errors when I try to run jest tests in Webstorm using yarn test.

C:\Users\larry.jones\AppData\Roaming\npm\yarn.cmd test
FAIL src/result-functional.test.ts
● Test suite failed to run

Jest encountered an unexpected token

Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.     

Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

By default "node_modules" folder is ignored by transformers.

Here's what you can do:
 • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
 • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
 • 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/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation

Details:

C:\src\Brew\Larry\typescript\learn-true-myth\node_modules\true-myth\dist\public\index.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export { Maybe } from './maybe.js';
                                                                                  ^^^^^^

SyntaxError: Unexpected token 'export'

> 1 | import Result from 'true-myth';
    | ^
  2 |
  3 | test('canary test', () => {
  4 |     expect(2 + 2).toEqual(4);

  at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1728:14)
  at Object.<anonymous> (src/result-functional.test.ts:1:1)

Test Suites: 1 failed, 1 total
Tests: 0 total
Snapshots: 0 total
Time: 0.948 s
Ran all test suites related to changed files.

[chriskrycho]

I believe this is a function of your Node and TS configurations, based on the issues you're seeing. Per the release notes for v6, you must:

• be on Node 14+
• be on TS 4.7+
• be using moduleResolution: "Node16" in your tsconfig.json
• be using type: "module" or using import() to import the files if in a CJS build

If all of those are true and you’re still having this issue, please let us know!

(Related, but not identical: #380)

[chriskrycho]

As noted below, we've updated the README in #434 to make the requirements for v6 that much clearer. v5 should continue to be useful, as the differences between it and v6 are relatively small (the big change was this switch!)

[kee-oth]

I'm experiencing the same issue. The issue with the true-myth package is resolved if I switch

moduleResolution: "node"

to

moduleResolution: "Node16"

but that breaks a lot of my other imports. Is there a way to have True Myth work with moduleResolution: "node"?

[chriskrycho]

We'll continue to consider it, as this transition is proving pretty tough for the JS/TS community. (Not a promise, just a note that we are thinking about it.) See #380 for some previous discussion!

[chriskrycho]

At least for now, we are not going to change this; instead, we're making it clearer in the README (see #434). Thanks!