Rewrite action in PureScript and add Purty (#1)

Author: thomashoneyman

.github/workflows/integration.yml

@@ -0,0 +1,19 @@
+name: Integration
+
+on: [push]
+
+jobs:
+  test-install:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./ # equivalent to thomashoneyman/setup-purescript@<branch>
+      - name: Check tools are installed correctly
+        run: |
+          purty src/Main.purs
+          spago build --purs-args '--codegen corefn,js'
+          zephyr -f Main.main

.gitignore

@@ -5,3 +5,8 @@
 
 # Dependencies
 node_modules
+
+# PureScript
+output
+dce-output
+generated-docs

README.md

@@ -5,6 +5,7 @@ A GitHub Action which sets up a PureScript toolchain for CI. Contains the follow
 - The [PureScript compiler](https://github.com/purescript/purescript)
 - The [Spago package manager and build tool](https://github.com/purescript/spago)
 - The [Zephyr dead code elimination tool](https://github.com/coot/zephyr)
+- The [Purty source code formatter](https://gitlab.com/joneshf/purty)
 
 This action is designed to support tools with static binaries. Your PureScript project may also depend on tooling and libraries provided by the NPM ecosystem, in which case you will also want to use the [setup-node](https://github.com/actions/setup-node) action.
 
@@ -16,7 +17,7 @@ See the [action.yml](action.yml) file for all possible inputs and outputs.
 
 ### Basic
 
-Get the latest versions of PureScript, Spago, and Zephyr in the environment:
+Use the PureScript toolchain with the latest version of each tool (resolved from GitHub releases or the latest tag with a valid semantic version):
 
 ```yaml
 steps:
@@ -27,7 +28,7 @@ steps:
 
 ### Use Specific Versions
 
-Use specific versions of any tool by supplying a valid semantic version (only exact versions currently supported):
+Use a specific version of any tool by supplying a valid semantic version (only exact versions currently supported):
 
 ```yaml
 steps:
@@ -36,19 +37,31 @@ steps:
     with:
       purescript-version: "0.13.8"
       spago-version: "0.15.3"
+      purty-version: "6.2.0"
       zephyr-version: "0.3.2"
   - run: spago build
 ```
 
-### Cache Library Dependencies (Coming Soon)
+## Development
 
-Automatically build and cache library dependencies between workflow runs by supplying a path to a Spago config file:
+Enter a development shell with necessary tools installed:
 
-```yaml
-steps:
-  - uses: actions/checkout@v2
-  - uses: thomashoneyman/setup-purescript@master
-    with:
-      cache: "spago.dhall"
-  - run: spago build
+```sh
+nix-shell
+```
+
+If you need any additional tools not included in this Nix expression or available via NPM, please feel free to add them via [easy-purescript-nix](https://github.com/justinwoo/easy-purescript-nix).
+
+Next, install NPM dependencies:
+
+```sh
+npm install
 ```
+
+GitHub Actions uses the `action.yml` file to define the action and the `dist/index.js` file to execute it. After making any changes to the source code, make sure those changes are visible by running:
+
+```sh
+npm run package
+```
+
+This will bundle and minify the source code so it is available to the end user.

action.yml

@@ -8,6 +8,9 @@ inputs:
   spago-version:
     description: "The Spago version to install. Examples: latest, 0.15.3"
     default: "latest"
+  purty-version:
+    description: "The Purty version to install. Examples: latest, 6.2.0"
+    default: "latest"
   zephyr-version:
     description: "The Zephyr version to install. Examples: latest, 0.3.2"
     default: "latest"