Add pursVersions CLI script (#630)

* Add pursVersions CLI script

* Add test

* Test interpreter

app/src/App/CLI/PursVersions.purs

@@ -0,0 +1,26 @@
+module Registry.App.CLI.PursVersions where
+
+import Registry.App.Prelude
+
+import Data.Array as Array
+import Data.Array.NonEmpty as NEA
+import Data.String as String
+import Node.Library.Execa as Execa
+import Registry.Version as Version
+import Run (AFF, Run)
+import Run as Run
+import Run.Except (EXCEPT)
+import Run.Except as Except
+
+pursVersions :: forall r. Run (EXCEPT String + AFF + r) (NonEmptyArray Version)
+pursVersions = do
+  result <- Run.liftAff $ _.result =<< Execa.execa "purs-versions" [] identity
+  { stdout } <- Except.rethrow $ lmap (\{ stdout, stderr } -> stdout <> stderr) result
+  let { fail, success } = partitionEithers $ map Version.parse (String.split (String.Pattern " ") stdout)
+
+  when (Array.length fail > 0) do
+    Except.throw (String.joinWith ", " fail)
+
+  case NEA.fromArray success of
+    Nothing -> Except.throw "No purs versions"
+    Just arr -> pure arr

app/test/App/CLI/PursVersions.purs

@@ -0,0 +1,51 @@
+module Test.Registry.App.CLI.PursVersions (spec) where
+
+import Registry.App.Prelude
+
+import Data.Array as Array
+import Data.Array.NonEmpty as NEA
+import Registry.App.CLI.PursVersions (pursVersions)
+import Registry.Test.Assert as Assert
+import Registry.Test.Assert.Run as Test.Run
+import Registry.Version as Version
+import Test.Spec as Spec
+
+-- NOTE: This should be kept up to date as new versions of the compiler are released.
+-- Upon release of a new compiler version and update of `purescript-overlay`, the tests below will fail until the version is added here.
+knownCompilers :: Array Version
+knownCompilers = map (unsafeFromRight <<< Version.parse)
+  [ "0.13.0"
+  , "0.13.2"
+  , "0.13.3"
+  , "0.13.4"
+  , "0.13.5"
+  , "0.13.6"
+  , "0.13.8"
+  , "0.14.0"
+  , "0.14.1"
+  , "0.14.2"
+  , "0.14.3"
+  , "0.14.4"
+  , "0.14.5"
+  , "0.14.6"
+  , "0.14.7"
+  , "0.14.8"
+  , "0.14.9"
+  , "0.15.0"
+  , "0.15.2"
+  , "0.15.3"
+  , "0.15.4"
+  , "0.15.5"
+  , "0.15.6"
+  , "0.15.7"
+  , "0.15.8"
+  , "0.15.9"
+  , "0.15.10"
+  ]
+
+spec :: Spec.Spec Unit
+spec = do
+  Spec.it "All expected versions are present in purs-version" do
+    versionsNonEmpty <- Test.Run.runBaseEffects pursVersions
+    let versions = NEA.toArray versionsNonEmpty
+    Array.sort versions `Assert.shouldEqual` Array.sort knownCompilers

app/test/Main.purs

@@ -7,6 +7,7 @@ import Test.Registry.App.API as Test.API
 import Test.Registry.App.Auth as Test.Auth
 import Test.Registry.App.CLI.Licensee as Test.CLI.Licensee
 import Test.Registry.App.CLI.Purs as Test.CLI.Purs
+import Test.Registry.App.CLI.PursVersions as Test.CLI.PursVersions
 import Test.Registry.App.CLI.Tar as Test.CLI.Tar
 import Test.Registry.App.Effect.PackageSets as Test.Effect.PackageSets
 import Test.Registry.App.GitHubIssue as Test.GitHubIssue
@@ -24,6 +25,7 @@ main = launchAff_ $ runSpec' (defaultConfig { timeout = Just $ Milliseconds 10_0
     Spec.describe "Licensee" Test.CLI.Licensee.spec
     Spec.describe "Tar" Test.CLI.Tar.spec
     Spec.describe "Purs" Test.CLI.Purs.spec
+    Spec.describe "PursVersions" Test.CLI.PursVersions.spec
 
   Spec.describe "Registry.App.Effect" do
     Test.Effect.PackageSets.spec