fix(provider): detect source code drift and validate package/function references

terraform/provider/internal/resources/function_resource_test.go

@@ -1,6 +1,7 @@
 package resources
 
 import (
+	"encoding/base64"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-framework/types"
@@ -36,3 +37,40 @@ func TestFunctionToUnstructuredAndBack(t *testing.T) {
 		t.Fatalf("InvokeStrategy not set correctly")
 	}
 }
+
+func TestValidateEntrypointAgainstPackageSourcePythonOK(t *testing.T) {
+	source := "def main():\n    return 'ok'\n"
+	pkg := &unstructured.Unstructured{Object: map[string]interface{}{
+		"spec": map[string]interface{}{
+			"deployment": map[string]interface{}{
+				"literal": base64.StdEncoding.EncodeToString([]byte(source)),
+			},
+		},
+	}}
+
+	if err := validateEntrypointAgainstPackageSource("main.main", pkg); err != nil {
+		t.Fatalf("expected valid entrypoint, got error: %v", err)
+	}
+}
+
+func TestValidateEntrypointAgainstPackageSourcePythonMissing(t *testing.T) {
+	source := "def another():\n    return 'ok'\n"
+	pkg := &unstructured.Unstructured{Object: map[string]interface{}{
+		"spec": map[string]interface{}{
+			"deployment": map[string]interface{}{
+				"literal": base64.StdEncoding.EncodeToString([]byte(source)),
+			},
+		},
+	}}
+
+	if err := validateEntrypointAgainstPackageSource("main.main", pkg); err == nil {
+		t.Fatalf("expected validation error for missing python function")
+	}
+}
+
+func TestValidateEntrypointAgainstPackageSourceBadFormat(t *testing.T) {
+	pkg := &unstructured.Unstructured{}
+	if err := validateEntrypointAgainstPackageSource("main", pkg); err == nil {
+		t.Fatalf("expected validation error for bad entrypoint format")
+	}
+}