add spago completions, fix spago bundle name (#129)

Author: thomashoneyman

manifests/build-support/mkDerivation.nix

@@ -13,6 +13,8 @@
   darwin,
   nodePackages,
   buildNpmPackage,
+  installShellFiles,
+  makeWrapper,
 }:
 version: source:
 let
@@ -29,6 +31,7 @@ let
   # build issues with Node 22+. Spago 0.93.45+ works with the standard nodejs.
   # See: https://github.com/purescript/registry-dev/blob/87c5900ff6fb7090cf2b085b7eb3f75371560522/nix/overlay.nix#L152
   isLegacySpago = isSpago && builtins.compareVersions version "0.93.45" < 0;
+
 in
 # Simple tarball without dependencies - just extract and link
 if isSimpleTarball then
@@ -74,6 +77,8 @@ else
     spagoNativeBuildInputs = [
       nodePackages.node-gyp
       python3
+      makeWrapper
+      installShellFiles
     ]
     ++ lib.optionals stdenv.isDarwin [ darwin.cctools ];
   in
@@ -101,5 +106,21 @@ else
       "--omit=optional"
     ];
 
+    # For spago: Replace the symlink with a wrapper that invokes node directly
+    # with the script renamed via a symlink. This fixes spago displaying
+    # "Usage: bundle.js" instead of "Usage: spago" (Node.js uses the script
+    # path for the program name). Also generate shell completions.
+    postInstall = lib.optionalString isSpago ''
+      rm $out/bin/${name}
+      ln -s $out/lib/node_modules/${name}/${js} $out/lib/node_modules/${name}/bin/${name}
+      makeWrapper ${selectedNodejs}/bin/node $out/bin/${name} \
+        --add-flags $out/lib/node_modules/${name}/bin/${name}
+
+      installShellCompletion --cmd ${name} \
+        --bash <($out/bin/${name} --bash-completion-script $out/bin/${name}) \
+        --zsh <($out/bin/${name} --zsh-completion-script $out/bin/${name}) \
+        --fish <($out/bin/${name} --fish-completion-script $out/bin/${name})
+    '';
+
     meta = commonMeta;
   }