From 3dbf0e24e450cc51282eef3f1ac53dcb3d3f0c60 Mon Sep 17 00:00:00 2001
From: Tyler Rockwood <rockwotj@users.noreply.github.com>
Date: Tue, 4 Sep 2018 09:06:29 -0700
Subject: [PATCH] Implement a nullable annotation for fields and messages (#26)

* Implement a nullable annotation for fields and messages

* Add back deleted tests
---
 firebase_rules_generator/generator.cc | 10 +++++++++-
 proto/firebase_rules_options.proto    |  2 ++
 testdata/testA.proto                  | 17 +++++++++++++++++
 testdata/testA.rules                  | 14 ++++++++++++++
 4 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 testdata/testA.proto
 create mode 100644 testdata/testA.rules

diff --git a/firebase_rules_generator/generator.cc b/firebase_rules_generator/generator.cc
index 4c81bff..50ef1a2 100644
--- a/firebase_rules_generator/generator.cc
+++ b/firebase_rules_generator/generator.cc
@@ -457,7 +457,15 @@ bool RulesGenerator::GenerateField(const protobuf::FieldDescriptor *field,
   if (options.has_validate()) {
     printer.Print(" && ($validate$)", "validate", options.validate());
   }
-  printer.Print("))");
+  printer.Print(")");
+  const auto &msg_options =
+      field->containing_type()->options().GetExtension(firebase_rules_message);
+  bool nullable =
+      (!options.has_nullable() && msg_options.nullable()) || options.nullable();
+  if (nullable) {
+    printer.Print(" || resource.$name$ is null", "name", field->json_name());
+  }
+  printer.Print(")");
   return true;
 }
 
diff --git a/proto/firebase_rules_options.proto b/proto/firebase_rules_options.proto
index fa24389..45297bb 100644
--- a/proto/firebase_rules_options.proto
+++ b/proto/firebase_rules_options.proto
@@ -7,11 +7,13 @@ import "google/protobuf/descriptor.proto";
 message RulesMessageOptions {
   optional string validate = 1;
   optional bool extra_properties = 2 [default = false];
+  optional bool nullable = 3 [default = false];
 }
 
 message RulesFieldOptions {
   optional string validate = 1;
   optional bool reference_type = 2 [default = false];
+  optional bool nullable = 3 [default = false];
 }
 
 message RulesFileOptions {
diff --git a/testdata/testA.proto b/testdata/testA.proto
new file mode 100644
index 0000000..4ee223c
--- /dev/null
+++ b/testdata/testA.proto
@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package example;
+
+import "firebase_rules_options.proto";
+
+message NullableExample {
+  string foo = 1;
+  string bar = 2
+      [(google.firebase.rules.firebase_rules_field).nullable = false];
+  option (google.firebase.rules.firebase_rules_message).nullable = true;
+}
+
+message Example {
+  string foo = 1;
+  string bar = 2 [(google.firebase.rules.firebase_rules_field).nullable = true];
+}
diff --git a/testdata/testA.rules b/testdata/testA.rules
new file mode 100644
index 0000000..16172b4
--- /dev/null
+++ b/testdata/testA.rules
@@ -0,0 +1,14 @@
+// @@START_GENERATED_FUNCTIONS@@
+function isNullableExampleMessage(resource) {
+  return resource.keys().hasAll([]) &&
+          (resource.keys().hasOnly(['bar','foo'])) &&
+          ((!resource.keys().hasAny(['foo'])) || (resource.foo is string) || resource.foo is null) &&
+          ((!resource.keys().hasAny(['bar'])) || (resource.bar is string));
+}
+function isExampleMessage(resource) {
+  return resource.keys().hasAll([]) &&
+          (resource.keys().hasOnly(['bar','foo'])) &&
+          ((!resource.keys().hasAny(['foo'])) || (resource.foo is string)) &&
+          ((!resource.keys().hasAny(['bar'])) || (resource.bar is string) || resource.bar is null);
+}
+// @@END_GENERATED_FUNCTIONS@@