From b8a27d3d99bbf1eaf711ce816e1d4148fc135197 Mon Sep 17 00:00:00 2001
From: Jamie Tanna <jamie.tanna@rootly.com>
Date: Mon, 4 May 2026 14:15:29 +0100
Subject: [PATCH] test: don't allow `interface{}` types

As noted in PRF-1956, we had some types that are defined as aliases of
`interface{}`, which reduce the type safety for our users.

To avoid this happening again, we can introduce a test to validate these
do not return again.

Co-authored-by: Claude Sonnet 4.6 <jamie.tanna+claude-code@rootly.com>
---
 generated_test.go | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 generated_test.go

diff --git a/generated_test.go b/generated_test.go
new file mode 100644
index 0000000..c722a3f
--- /dev/null
+++ b/generated_test.go
@@ -0,0 +1,37 @@
+package rootly
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"testing"
+)
+
+func TestNoInterfaceTypeAliases(t *testing.T) {
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, "schema.gen.go", nil, 0)
+	if err != nil {
+		t.Fatalf("failed to parse schema.gen.go: %v", err)
+	}
+
+	for _, decl := range f.Decls {
+		genDecl, ok := decl.(*ast.GenDecl)
+		if !ok || genDecl.Tok != token.TYPE {
+			continue
+		}
+		for _, spec := range genDecl.Specs {
+			typeSpec, ok := spec.(*ast.TypeSpec)
+			if !ok || !typeSpec.Assign.IsValid() {
+				continue
+			}
+
+			t.Run(typeSpec.Name.Name+" should not be an interface{}", func(t *testing.T) {
+				iface, ok := typeSpec.Type.(*ast.InterfaceType)
+
+				if ok && iface.Methods.NumFields() == 0 {
+					t.Fail()
+				}
+			})
+		}
+	}
+}