[DEVOPS-936] hydra for hlint

Author: disassembler

default.nix

@@ -156,6 +156,7 @@ let
     demoCluster = pkgs.callPackage ./scripts/launch/demo-cluster { inherit gitrev; };
     tests = {
       shellcheck = pkgs.callPackage ./scripts/test/shellcheck.nix { src = ./.; };
+      hlint = pkgs.callPackage ./scripts/test/hlint.nix { src = ./.; };
       stylishHaskell = pkgs.callPackage ./scripts/test/stylish.nix { src = ./.; stylish-haskell = cardanoPkgs.stylish-haskell; };
       buildWalletIntegration = pkgs.callPackage ./scripts/test/wallet/integration/build-test.nix { inherit walletIntegrationTests pkgs; };
       swaggerSchemaValidation = pkgs.callPackage ./scripts/test/wallet/swaggerSchemaValidation.nix { inherit gitrev; };

scripts/test/hlint.nix

@@ -0,0 +1,36 @@
+{ runCommand, hlint, src, lib }:
+
+let
+  cleanSourceFilter = with lib;
+    name: type: let baseName = baseNameOf (toString name); in (
+      (type == "regular" && hasSuffix ".hs" baseName) ||
+      (type == "regular" && hasSuffix ".yaml" baseName) ||
+      (type == "directory")
+    );
+  src' = builtins.filterSource cleanSourceFilter src;
+in
+runCommand "cardano-hlint-check" { buildInputs = [ hlint ]; } ''
+  set +e
+  # Networking is not in here, because it has a very different codestyle (doesn't use universum).
+  # This is bad and should probably be fixed.
+  projects=("util" "binary" "crypto" "core" "db" "lrc" "infra" "ssc" "txp" "update" "delegation" "node" "tools" "client" "generator" "auxx" "explorer" "wallet" "wallet-new")
+  cd ${src'}
+  hlint lib/src lib/test lib/bench "''${projects[@]}"
+  EXIT_CODE=$?
+  if [[ $EXIT_CODE != 0 ]]
+  then
+    echo '====================================================================='
+    echo 'Note: to ignore a particular hint (e.g. "Reduce duplication"), write'
+    echo 'this in the source file:'
+    tput bold
+    echo '{-# ANN module ("HLint: ignore Reduce duplication" :: Text) #-}'
+    tput sgr0
+    echo 'You can also apply it just to a particular function, which is better:'
+    tput bold
+    echo '{-# ANN funcName ("HLint: ignore Reduce duplication" :: Text) #-}'
+    tput sgr0
+    exit $EXIT_CODE
+  else
+    echo $EXIT_CODE > $out
+  fi
+''