feat: Read-only access mode rpc (#1081)

Author: Vinzent03

infra/postgrest/db/00-schema.sql

@@ -68,6 +68,13 @@ CREATE FUNCTION public.get_integer()
     End;
 $$ LANGUAGE plpgsql;
 
+CREATE FUNCTION public.get_array_element(arr integer[], index integer)
+    RETURNS integer AS $$
+    BEGIN
+        RETURN arr[index];
+    END;
+$$ LANGUAGE plpgsql;
+
 -- SECOND SCHEMA USERS
 CREATE TYPE personal.user_status AS ENUM ('ONLINE', 'OFFLINE');
 CREATE TABLE personal.users(
@@ -103,4 +110,4 @@ CREATE TABLE public.addresses (
   id bigint GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
   username text REFERENCES users NOT NULL,
   location geometry(POINT,4326)
-);
+);

packages/postgrest/lib/src/postgrest.dart

@@ -81,14 +81,25 @@ class PostgrestClient {
     );
   }
 
-  /// Perform a stored procedure call.
+  /// {@template postgrest_rpc}
+  /// Performs a stored procedure call.
+  ///
+  /// [fn] is the name of the function to call.
+  ///
+  /// [params] is an optinal object to pass as arguments to the function call.
+  ///
+  /// When [get] is set to `true`, the function will be called with read-only
+  /// access mode.
+  ///
+  /// {@endtemplate}
   ///
   /// ```dart
   /// supabase.rpc('get_status', params: {'name_param': 'supabot'})
   /// ```
   PostgrestFilterBuilder<T> rpc<T>(
     String fn, {
     Map? params,
+    bool get = false,
   }) {
     final url = '${this.url}/rpc/$fn';
     return PostgrestRpcBuilder(
@@ -97,7 +108,7 @@ class PostgrestClient {
       schema: _schema,
       httpClient: httpClient,
       isolate: _isolate,
-    ).rpc(params);
+    ).rpc(params, get);
   }
 
   Future<void> dispose() async {

packages/postgrest/lib/src/postgrest_builder.dart

@@ -348,6 +348,15 @@ class PostgrestBuilder<T, S, R> implements Future<T> {
     return _url.replace(queryParameters: searchParams);
   }
 
+  /// Convert list filter to query params string
+  String _cleanFilterArray(List filter) {
+    if (filter.every((element) => element is num)) {
+      return filter.map((s) => '$s').join(',');
+    } else {
+      return filter.map((s) => '"$s"').join(',');
+    }
+  }
+
   @override
   Stream<T> asStream() {
     final controller = StreamController<T>.broadcast();

packages/postgrest/lib/src/postgrest_filter_builder.dart

@@ -7,15 +7,6 @@ class PostgrestFilterBuilder<T> extends PostgrestTransformBuilder<T> {
   PostgrestFilterBuilder<T> copyWithUrl(Uri url) =>
       PostgrestFilterBuilder(_copyWith(url: url));
 
-  /// Convert list filter to query params string
-  String _cleanFilterArray(List filter) {
-    if (filter.every((element) => element is num)) {
-      return filter.map((s) => '$s').join(',');
-    } else {
-      return filter.map((s) => '"$s"').join(',');
-    }
-  }
-
   /// Finds all rows which doesn't satisfy the filter.
   ///
   /// ```dart

packages/postgrest/lib/src/postgrest_rpc_builder.dart

@@ -17,12 +17,36 @@ class PostgrestRpcBuilder extends RawPostgrestBuilder {
           ),
         );
 
-  /// Performs stored procedures on the database.
+  /// {@macro postgrest_rpc}
   PostgrestFilterBuilder<T> rpc<T>([
     Object? params,
+    bool get = false,
   ]) {
+    var newUrl = _url;
+    final String method;
+    if (get) {
+      method = METHOD_GET;
+      if (params is Map) {
+        for (final entry in params.entries) {
+          assert(entry.key is String,
+              "RPC params map keys must be of type String");
+
+          final MapEntry(:key, :value) = entry;
+          final formattedValue =
+              value is List ? '{${_cleanFilterArray(value)}}' : value;
+          newUrl =
+              appendSearchParams(key.toString(), '$formattedValue', newUrl);
+        }
+      } else {
+        throw ArgumentError.value(params, 'params', 'argument must be a Map');
+      }
+    } else {
+      method = METHOD_POST;
+    }
+
     return PostgrestFilterBuilder(_copyWithType(
-      method: METHOD_POST,
+      method: method,
+      url: newUrl,
       body: params,
     ));
   }

packages/postgrest/test/basic_test.dart

@@ -63,6 +63,29 @@ void main() {
       expect(res, isA<int>());
     });
 
+    test('stored procedure with array parameter', () async {
+      final res = await postgrest.rpc<int>(
+        'get_array_element',
+        params: {
+          'arr': [37, 420, 64],
+          'index': 2
+        },
+      );
+      expect(res, 420);
+    });
+
+    test('stored procedure with read-only access mode', () async {
+      final res = await postgrest.rpc<int>(
+        'get_array_element',
+        params: {
+          'arr': [37, 420, 64],
+          'index': 2
+        },
+        get: true,
+      );
+      expect(res, 420);
+    });
+
     test('custom headers', () async {
       final postgrest = PostgrestClient(rootUrl, headers: {'apikey': 'foo'});
       expect(postgrest.headers['apikey'], 'foo');
@@ -448,10 +471,12 @@ void main() {
     });
   });
   group("Custom http client", () {
+    CustomHttpClient customHttpClient = CustomHttpClient();
     setUp(() {
+      customHttpClient = CustomHttpClient();
       postgrestCustomHttpClient = PostgrestClient(
         rootUrl,
-        httpClient: CustomHttpClient(),
+        httpClient: customHttpClient,
       );
     });
 
@@ -486,6 +511,23 @@ void main() {
             'Stored procedure was able to be called, even tho it does not exist');
       } on PostgrestException catch (error) {
         expect(error.code, '420');
+        expect(customHttpClient.lastRequest?.method, "POST");
+      }
+    });
+
+    test('stored procedure call in read-only access mode', () async {
+      try {
+        await postgrestCustomHttpClient.rpc<String>(
+          'get_status',
+          params: {'name_param': 'supabot'},
+          get: true,
+        );
+        fail(
+            'Stored procedure was able to be called, even tho it does not exist');
+      } on PostgrestException catch (error) {
+        expect(error.code, '420');
+        expect(customHttpClient.lastRequest?.method, "GET");
+        expect(customHttpClient.lastBody, isEmpty);
       }
     });
   });

packages/postgrest/test/custom_http_client.dart

@@ -1,10 +1,15 @@
+import 'dart:typed_data';
+
 import 'package:http/http.dart';
 
 class CustomHttpClient extends BaseClient {
   BaseRequest? lastRequest;
+  Uint8List? lastBody;
   @override
   Future<StreamedResponse> send(BaseRequest request) async {
     lastRequest = request;
+    final bodyStream = request.finalize();
+    lastBody = await bodyStream.toBytes();
 
     if (request.url.path.endsWith("empty-succ")) {
       return StreamedResponse(
@@ -15,7 +20,7 @@ class CustomHttpClient extends BaseClient {
     }
     //Return custom status code to check for usage of this client.
     return StreamedResponse(
-      request.finalize(),
+      Stream.value(lastBody!),
       420,
       request: request,
     );

packages/postgrest/test/reset_helper.dart

@@ -15,7 +15,6 @@ class ResetHelper {
     _users = (await _postgrest.from('users').select());
     _channels = await _postgrest.from('channels').select();
     _messages = await _postgrest.from('messages').select();
-    print('messages has ${_messages.length} items');
     _reactions = await _postgrest.from('reactions').select();
     _addresses = await _postgrest.from('addresses').select();
   }

packages/supabase/lib/src/supabase_client.dart

@@ -200,13 +200,14 @@ class SupabaseClient {
     );
   }
 
-  /// Perform a stored procedure call.
+  /// {@macro postgrest_rpc}
   PostgrestFilterBuilder<T> rpc<T>(
     String fn, {
     Map<String, dynamic>? params,
+    get = false,
   }) {
     rest.headers.addAll({...rest.headers, ...headers});
-    return rest.rpc(fn, params: params);
+    return rest.rpc(fn, params: params, get: get);
   }
 
   /// Creates a Realtime channel with Broadcast, Presence, and Postgres Changes.

packages/supabase/lib/src/supabase_query_schema.dart

@@ -48,13 +48,18 @@ class SupabaseQuerySchema {
     );
   }
 
-  /// Perform a stored procedure call.
+  /// {@macro postgrest_rpc}
   PostgrestFilterBuilder<T> rpc<T>(
     String fn, {
     Map<String, dynamic>? params,
+    bool get = false,
   }) {
     _rest.headers.addAll({..._rest.headers, ..._headers});
-    return _rest.rpc(fn, params: params);
+    return _rest.rpc(
+      fn,
+      params: params,
+      get: get,
+    );
   }
 
   SupabaseQuerySchema schema(String schema) {