lib.packagesFromDirectoryRecursive: add tests for nested scopes

lib/tests/misc.nix

@@ -2520,4 +2520,38 @@ runTests {
     };
     expected = "c";
   };
+
+  # Check that `packagesFromDirectoryRecursive` can be used to create scopes
+  # for sub-directories
+  testPackagesFromDirectoryNestedScopes = let
+    inherit (lib) makeScope recurseIntoAttrs;
+    emptyScope = makeScope lib.callPackageWith (_: {});
+  in {
+    expr = lib.filterAttrsRecursive (name: value: !lib.elem name [ "callPackage" "newScope" "overrideScope" "packages" ]) (packagesFromDirectoryRecursive {
+      inherit (emptyScope) callPackage newScope;
+      recurseIntoDirectory = f: { newScope, ... }@args:
+        recurseIntoAttrs (makeScope newScope (self:
+          f (args // {
+            inherit (self) callPackage newScope;
+          })
+        ));
+      directory = ./packages-from-directory/scope;
+    });
+    expected = lib.recurseIntoAttrs {
+      a = "a";
+      b = "b";
+      # Note: Other files/directories in `./test-data/c/` are ignored and can be
+      # used by `package.nix`.
+      c = "c";
+      my-namespace = lib.recurseIntoAttrs {
+        d = "d";
+        e = "e";
+        f = "f";
+        my-sub-namespace = lib.recurseIntoAttrs {
+          g = "g";
+          h = "h";
+        };
+      };
+    };
+  };
 }

lib/tests/packages-from-directory/scope/a.nix

@@ -0,0 +1 @@
+{ }: "a"

lib/tests/packages-from-directory/scope/b.nix

@@ -0,0 +1,3 @@
+{ a }:
+assert a == "a";
+"b"

lib/tests/packages-from-directory/scope/c/not-a-namespace/not-a-package.nix

@@ -0,0 +1 @@
+{ }

lib/tests/packages-from-directory/scope/c/package.nix

@@ -0,0 +1 @@
+{ }: "c"

lib/tests/packages-from-directory/scope/c/support-definitions.nix

@@ -0,0 +1 @@
+{ }

lib/tests/packages-from-directory/scope/my-namespace/d.nix

@@ -0,0 +1,5 @@
+{ a, e }:
+# Check we can get parameter from the parent scope(s) as well as the current one
+assert a == "a";
+assert e == "e";
+"d"

lib/tests/packages-from-directory/scope/my-namespace/e.nix

@@ -0,0 +1,3 @@
+{ d }:
+# Check that mutual recursion is possible
+"e"

lib/tests/packages-from-directory/scope/my-namespace/f/package.nix

@@ -0,0 +1 @@
+{ }: "f"

lib/tests/packages-from-directory/scope/my-namespace/my-sub-namespace/g.nix

@@ -0,0 +1,7 @@
+{
+  a,
+  d,
+  h,
+}:
+# Check we can get parameters from ancestral scopes (e.g. the scope's grandparent)
+"g"

lib/tests/packages-from-directory/scope/my-namespace/my-sub-namespace/h.nix

@@ -0,0 +1 @@
+{ }: "h"