1 files changed, 12 insertions, 0 deletions
diff --git a/third_party/nix/tests/filter-source.nix b/third_party/nix/tests/filter-source.nix
new file mode 100644
index 0000000000..9071636394
--- /dev/null
+++ b/third_party/nix/tests/filter-source.nix
@@ -0,0 +1,12 @@
+with import ./config.nix;
+
+mkDerivation {
+  name = "filter";
+  builder = builtins.toFile "builder" "ln -s $input $out";
+  input =
+    let filter = path: type:
+      type != "symlink"
+      && baseNameOf path != "foo"
+      && !((import ./lang/lib.nix).hasSuffix ".bak" (baseNameOf path));
+    in builtins.filterSource filter ((builtins.getEnv "TEST_ROOT") + "/filterin");
+}