1 files changed, 23 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/build-support/trivial-builders/test/writeClosure-union.nix b/nixpkgs/pkgs/build-support/trivial-builders/test/writeClosure-union.nix
new file mode 100644
index 000000000000..92a2bf9f0988
--- /dev/null
+++ b/nixpkgs/pkgs/build-support/trivial-builders/test/writeClosure-union.nix
@@ -0,0 +1,23 @@
+{ lib
+, runCommandLocal
+  # Test targets
+, writeClosure
+, samples
+}:
+runCommandLocal "test-trivial-builders-writeClosure-union" {
+  __structuredAttrs = true;
+  closures = lib.mapAttrs (n: v: writeClosure [ v ]) samples;
+  collectiveClosure = writeClosure (lib.attrValues samples);
+  inherit samples;
+  meta.maintainers = with lib.maintainers; [
+    ShamrockLee
+  ];
+} ''
+  set -eu -o pipefail
+  echo >&2 Testing mixed closures...
+  echo >&2 Checking all samples "(''${samples[*]})" "$collectiveClosure"
+  diff -U3 \
+    <(sort <"$collectiveClosure") \
+    <(cat "''${closures[@]}" | sort | uniq)
+  touch "$out"
+''