lib.types.unique: Check inner type deeply

This doesn't change uniq. Why not?

- In NixOS it seems that uniq is only used with
  simple types that are fully checked by t.check.

- It exists for much longer and is used more widely.

- I believe we should deprecate it, because unique was
  already better.

- unique can be a proving ground.

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/tests/modules.sh b/lib/tests/modules.sh
index a90ff4ad9a2f6..1221ba7143f64 100755
--- a/lib/tests/modules.sh
+++ b/lib/tests/modules.sh
@@ -406,6 +406,16 @@ checkConfigOutput "{}" config.submodule.a ./emptyValues.nix
 checkConfigError 'The option .int.a. is used but not defined' config.int.a ./emptyValues.nix
 checkConfigError 'The option .nonEmptyList.a. is used but not defined' config.nonEmptyList.a ./emptyValues.nix
 
+# types.unique
+#   requires a single definition
+checkConfigError 'The option .examples\.merged. is defined multiple times while it.s expected to be unique' config.examples.merged.a ./types-unique.nix
+#   user message is printed
+checkConfigError 'We require a single definition, because seeing the whole value at once helps us maintain critical invariants of our system.' config.examples.merged.a ./types-unique.nix
+#   let the inner merge function check the values (on demand)
+checkConfigError 'A definition for option .examples\.badLazyType\.a. is not of type .string.' config.examples.badLazyType.a ./types-unique.nix
+#   overriding still works (unlike option uniqueness)
+checkConfigOutput '^"bee"$' config.examples.override.b ./types-unique.nix
+
 ## types.raw
 checkConfigOutput '^true$' config.unprocessedNestingEvaluates.success ./raw.nix
 checkConfigOutput "10" config.processedToplevel ./raw.nix