1 files changed, 69 insertions, 5 deletions
diff --git a/internal/rosa/azalea/evaluate_test.go b/internal/rosa/azalea/evaluate_test.go
index 4a6c2f56..049fcb52 100644
--- a/internal/rosa/azalea/evaluate_test.go
+++ b/internal/rosa/azalea/evaluate_test.go
@@ -100,15 +100,79 @@ func TestEvaluate(t *testing.T) {
 			Err:  UndefinedError("f"),
 		}},
 
-		{"error wrap deep", `f { v = nil; }`, makeStackCheck(func(
+		{"error wrap deep", `f { v = nonexistent; }`, makeStackCheck(func(
 			FArgs,
 		) (any, error) {
 			panic("unreachable")
 		}), "", EvaluationError{
-			Expr: Ident("nil"),
-			Err:  UndefinedError("nil"),
+			Expr: Ident("nonexistent"),
+			Err:  UndefinedError("nonexistent"),
 		}},
 
+		{"nil", `f { v = nil; }`, checkArgs(FArgs{
+			{K: unique.Make(Ident("v")), V: Nil{}},
+		}), "\xfd", nil},
+
+		{"apply nil string", `f { v = nil; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			var s string
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &s,
+			})
+			v = s
+			return
+		}), "", EvaluationError{
+			Expr: Func{
+				Ident: Ident("f"),
+				Args: []Arg{
+					{K: []Ident{"v"}, V: Val{Ident("nil")}},
+				},
+			},
+			Err: NilError{Type: reflect.TypeFor[string]()},
+		}},
+
+		{"apply nil AString", `f { v = nil; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			s := AString{}
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &s,
+			})
+			v = s.V
+			if !s.Nil {
+				err = fmt.Errorf("got non-nil string %q", s.V)
+			}
+			return
+		}), "", nil},
+
+		{"apply AString", `f { v = "\xfd"; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			s := AString{}
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &s,
+			})
+			v = s.V
+			if s.Nil {
+				err = fmt.Errorf("unexpected nil %q", s.V)
+			}
+			return
+		}), "\xfd", nil},
+
+		{"apply nil", `f { v = nil; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			s := make([]struct{}, 9)
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &s,
+			})
+			if s != nil {
+				err = fmt.Errorf("got non-nil value %#v", s)
+			}
+			return
+		}), "", nil},
+
 		{"common inputs", `package name { inputs, v = []; }`, nil, "", EvaluationError{
 			Expr: Func{
 				Ident:   Ident("name"),
@@ -214,8 +278,8 @@ func TestEvaluate(t *testing.T) {
 			}
 
 			var errEquals bool
-			if _, ok := errors.AsType[TypeError](err); ok {
-				errEquals = errors.Is(err, tc.err)
+			if e, ok := errors.AsType[TypeError](err); ok {
+				errEquals = e.Is(tc.err)
 			} else {
 				errEquals = reflect.DeepEqual(err, tc.err)
 			}