Moving CLJS libraries form leiningen to shadow-cljs (deps.edn, transitive NPM deps)

move-from-lein-to-shadow.md

To resume the changes required to move a CLJS library from leiningen to shadow-cljs:

1. Create shadow-cljs.edn in the project root

• example: https://github.com/district0x/cljs-web3-next/blob/master/shadow-cljs.edn
• it will probably need at least 2 targets: browser (to run tests locally during development) and karma (to run tests on the CI). Docs: https://shadow-cljs.github.io/docs/UsersGuide.html#target-browser

2. Create deps.edn in the project root and translate the Clojars dependencies from project.clj to there

• example: https://github.com/district0x/cljs-web3-next/blob/master/deps.edn
• after that project.clj can be removed (or after the next step in case you need to look up the NPM deps)

3. If there are direct NPM dependencies for that library / project, define these in src/deps.cljs

• NB! note the extension, it's .cljs not .edn, this is important
• after this you can remove package.json (and its respective lock-file)
• hint: if you want to force subsequent dependency updates to use Yarn, you can do yarn add shadow-cljs@2.19.3 which will generate package.json and yarn.lock, after which shadow-cljs will automatically use yarn for future dependency pulls yarn, otherwise it'll default to npm)

4. To build and publish JAR (normally CI publishes it)

• having moved away from leiningen, the "modern" way to do it is using Clojure's built int tools.build
• for that you can use as an example https://github.com/district0x/cljs-web3-next/blob/master/build.clj
• need to update lib and version symbols according to the library you're working on
• then to build on CI, update .circle/config.yml (example: https://github.com/district0x/cljs-web3-next/blob/master/.circleci/config.yml#L41-L48)
• commands to do it are documented in https://github.com/district0x/cljs-web3-next/blob/master/README.md#build--release-with-depsedn-and-toolsbuild

More example build, test & release commands are documented in https://github.com/district0x/cljs-web3-next/blob/master/README.md#new-build-test-and-release-commands