Upgrading to Elm 0.18 about elm

[trytriangles]

If the exercises aren't updated to the latest version consistently, I think @mattludwigs' new Elm version manager should be linked in the READMEs. Elm's updates so far have made pretty radical changes to fundamental features and syntax compared to other languages so it's likely to be a problem -- I know it was for me.

[tgecho]

Thanks for working through so much of this! I'm afraid we (I) didn't handle the 0.16 -> 0.17 transition very smoothly, and I've had even less time lately to think about this one.

One option might be to add a minimal package.json to each exercise along the lines of

{
  "scripts": {
    "test": "elm package install && elm-test *Tests.elm"
  },
  "dependencies": {
    "elm": "^0.18.0",
    "elm-test": "^0.18.0"
  }
}

We already have a node dependency due to elm-test. Running npm install followed by npm test would actually run the version of elm in the local node_modules folder, allowing it to not conflict with the global version.

If this solution is acceptable (and is shown to work on windows), the main question that remains is how to communicate it. Maybe add a tiny HOW_TO_RUN_TESTS.txt file to each exercise? 😄

[rebelwarrior]

Hi,
I seem to not be able to run tests, even when I try to change the Test file to upgrade it. This is the error I get no matter what I do.

[stdin]:12413
    if (typeof Elm === "undefined") { throw "elm-io config error: Elm is not defined. Make sure you call elm-io with a real Elm output file"}
                                      ^
elm-io config error: Elm is not defined. Make sure you call elm-io with a real Elm output file

[rebelwarrior]

The problem above seems to have gone away with elm-test 0.18.2

[rebelwarrior]

Recommend we use yarn for package management. This would allow easy installation of packages and keep them local to each test and future proof (at least to some degree) for future updates.

[tgecho]

@rebelwarrior I'm fond of Yarn myself. Though I haven't used it enough to be sure, my understanding is that it should be drop in compatible with npm for our purposes. In other words, we could make a package.json and tell people to npm install or yarn install and everything should work.