From aaf7596bc6ca5034b1541be94cdad91f9a61f00e Mon Sep 17 00:00:00 2001
From: Daniel Firth <daniel.firth@iohk.io>
Date: Mon, 30 Sep 2024 08:09:41 +0000
Subject: [PATCH] Add weeder

---
 cabal.project       | 3 +++
 flake.nix           | 1 +
 nix/hydra/shell.nix | 1 +
 weeder.toml         | 2 ++
 4 files changed, 7 insertions(+)
 create mode 100644 weeder.toml

diff --git a/cabal.project b/cabal.project
index f1ec8b642e7..8db45489881 100644
--- a/cabal.project
+++ b/cabal.project
@@ -41,3 +41,6 @@ benchmarks: True
 
 -- Always show detailed output for tests
 test-show-details: direct
+
+program-options
+  ghc-options: -fwrite-ide-info
diff --git a/flake.nix b/flake.nix
index f1ffb59e8db..d032401d7b0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -80,6 +80,7 @@
                   cabalProject = builtins.readFile (src + "/cabal.project");
                 };
                 hlint = pkgs.haskell-nix.tool compiler "hlint" "3.8";
+                weeder = pkgs.haskell-nix.tool compiler "weeder" "2.9.0";
                 cardano-cli = inputs.cardano-node.packages.${system}.cardano-cli;
                 cardano-node = inputs.cardano-node.packages.${system}.cardano-node;
                 mithril-client-cli = inputs.mithril.packages.${system}.mithril-client-cli;
diff --git a/nix/hydra/shell.nix b/nix/hydra/shell.nix
index 5b71876a0fc..2468d894a6d 100644
--- a/nix/hydra/shell.nix
+++ b/nix/hydra/shell.nix
@@ -45,6 +45,7 @@ let
     pkgs.treefmt
     # Handy to interact with the hydra-node via websockets
     pkgs.websocat
+    pkgs.weeder
     pkgs.yarn
     pkgs.yq
     # Use latest jq in all shells, to avoid 1.6 bug with large integers.
diff --git a/weeder.toml b/weeder.toml
new file mode 100644
index 00000000000..4215e181265
--- /dev/null
+++ b/weeder.toml
@@ -0,0 +1,2 @@
+roots = [ "^Main.main$" ]
+type-class-roots = true