feat: Support MultipartRequest in functions invoke (#977)

* feat: support MultipartRequest in functions invoke

* fix: export MultipartFile

* test: add tests for body encoding

* fix: set correct headers

packages/functions_client/lib/functions_client.dart

@@ -1,6 +1,6 @@
 library functions_client;
 
-export 'package:http/http.dart' show ByteStream;
+export 'package:http/http.dart' show ByteStream, MultipartFile;
 
 export 'src/functions_client.dart';
 export 'src/types.dart';

packages/functions_client/lib/src/constants.dart

@@ -2,7 +2,6 @@ import 'package:functions_client/src/version.dart';
 
 class Constants {
   static const defaultHeaders = {
-    'Content-Type': 'application/json',
     'X-Client-Info': 'functions-dart/$version',
   };
 }

packages/functions_client/lib/src/functions_client.dart

@@ -1,8 +1,10 @@
 import 'dart:convert';
+import 'dart:typed_data';
 
 import 'package:functions_client/src/constants.dart';
 import 'package:functions_client/src/types.dart';
 import 'package:http/http.dart' as http;
+import 'package:http/http.dart' show MultipartRequest;
 import 'package:yet_another_json_isolate/yet_another_json_isolate.dart';
 
 class FunctionsClient {
@@ -38,11 +40,17 @@ class FunctionsClient {
 
   /// Invokes a function
   ///
-  /// [functionName] - the name of the function to invoke
+  /// [functionName] is the name of the function to invoke
   ///
-  /// [headers]: object representing the headers to send with the request
+  /// [headers] to send with the request
+  ///
+  /// [body] of the request when [files] is null and can be of type String
+  /// or an Object that is encodable to JSON with `jsonEncode`.
+  /// If [files] is not null, [body] represents the fields of the
+  /// [MultipartRequest] and must be be of type `Map<String, String>`.
+  ///
+  /// [files] to send in a `MultipartRequest`. [body] is used for the fields.
   ///
-  /// [body]: the body of the request
   ///
   /// ```dart
   /// // Call a standard function
@@ -70,12 +78,11 @@ class FunctionsClient {
   Future<FunctionResponse> invoke(
     String functionName, {
     Map<String, String>? headers,
-    Map<String, dynamic>? body,
+    Object? body,
+    Iterable<http.MultipartFile>? files,
     Map<String, dynamic>? queryParameters,
     HttpMethod method = HttpMethod.post,
   }) async {
-    final bodyStr = body == null ? null : await _isolate.encode(body);
-
     final uri = Uri.parse('$_url/$functionName')
         .replace(queryParameters: queryParameters);
 
@@ -84,12 +91,44 @@ class FunctionsClient {
       if (headers != null) ...headers
     };
 
-    final request = http.Request(method.name, uri);
+    if (body != null &&
+        (headers == null || headers.containsKey("Content-Type") == false)) {
+      finalHeaders['Content-Type'] = switch (body) {
+        Uint8List() => 'application/octet-stream',
+        String() => 'text/plain',
+        _ => 'application/json',
+      };
+    }
+    final http.BaseRequest request;
+    if (files != null) {
+      assert(
+        body == null || body is Map<String, String>,
+        'body must be of type Map',
+      );
+      final fields = body as Map<String, String>?;
+
+      request = http.MultipartRequest(method.name, uri)
+        ..fields.addAll(fields ?? {})
+        ..files.addAll(files);
+    } else {
+      final bodyRequest = http.Request(method.name, uri);
+
+      final String? bodyStr;
+      if (body == null) {
+        bodyStr = null;
+      } else if (body is String) {
+        bodyStr = body;
+      } else {
+        bodyStr = await _isolate.encode(body);
+      }
+      if (bodyStr != null) bodyRequest.body = bodyStr;
+      request = bodyRequest;
+    }
 
     finalHeaders.forEach((key, value) {
       request.headers[key] = value;
     });
-    if (bodyStr != null) request.body = bodyStr;
+
     final response = await (_httpClient?.send(request) ?? request.send());
     final responseType = (response.headers['Content-Type'] ??
             response.headers['content-type'] ??

packages/functions_client/test/custom_http_client.dart

@@ -13,8 +13,9 @@ class CustomHttpClient extends BaseClient {
   Future<StreamedResponse> send(BaseRequest request) async {
     // Add request to receivedRequests list.
     receivedRequests = receivedRequests..add(request);
+    request.finalize();
 
-    if (request.url.path.endsWith("function")) {
+    if (request.url.path.endsWith("error-function")) {
       //Return custom status code to check for usage of this client.
       return StreamedResponse(
         Stream.value(utf8.encode(jsonEncode({"key": "Hello World"}))),
@@ -32,8 +33,22 @@ class CustomHttpClient extends BaseClient {
             "Content-Type": "text/event-stream",
           });
     } else {
+      final Stream<List<int>> stream;
+      if (request is MultipartRequest) {
+        stream = Stream.value(
+          utf8.encode(jsonEncode([
+            for (final file in request.files)
+              {
+                "name": file.field,
+                "content": await file.finalize().bytesToString()
+              }
+          ])),
+        );
+      } else {
+        stream = Stream.value(utf8.encode(jsonEncode({"key": "Hello World"})));
+      }
       return StreamedResponse(
-        Stream.value(utf8.encode(jsonEncode({"key": "Hello World"}))),
+        stream,
         200,
         request: request,
         headers: {

packages/functions_client/test/functions_dart_test.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 
 import 'package:functions_client/src/functions_client.dart';
 import 'package:functions_client/src/types.dart';
+import 'package:http/http.dart';
 import 'package:test/test.dart';
 import 'package:yet_another_json_isolate/yet_another_json_isolate.dart';
 
@@ -19,22 +20,24 @@ void main() {
     });
     test('function throws', () async {
       try {
-        await functionsCustomHttpClient.invoke('function');
+        await functionsCustomHttpClient.invoke('error-function');
         fail('should throw');
       } on FunctionException catch (e) {
         expect(e.status, 420);
       }
     });
 
     test('function call', () async {
-      final res = await functionsCustomHttpClient.invoke('function1');
+      final res = await functionsCustomHttpClient.invoke('function');
+      expect(
+          customHttpClient.receivedRequests.last.headers["Content-Type"], null);
       expect(res.data, {'key': 'Hello World'});
       expect(res.status, 200);
     });
 
     test('function call with query parameters', () async {
       final res = await functionsCustomHttpClient
-          .invoke('function1', queryParameters: {'key': 'value'});
+          .invoke('function', queryParameters: {'key': 'value'});
 
       final request = customHttpClient.receivedRequests.last;
 
@@ -43,6 +46,27 @@ void main() {
       expect(res.status, 200);
     });
 
+    test('function call with files', () async {
+      final fileName = "file.txt";
+      final fileContent = "Hello World";
+      final res = await functionsCustomHttpClient.invoke(
+        'function',
+        queryParameters: {'key': 'value'},
+        files: [
+          MultipartFile.fromString(fileName, fileContent),
+        ],
+      );
+
+      final request = customHttpClient.receivedRequests.last;
+
+      expect(request.url.queryParameters, {'key': 'value'});
+      expect(request.headers['Content-Type'], contains('multipart/form-data'));
+      expect(res.data, [
+        {'name': fileName, 'content': fileContent}
+      ]);
+      expect(res.status, 200);
+    });
+
     test('dispose isolate', () async {
       await functionsCustomHttpClient.dispose();
       expect(functionsCustomHttpClient.invoke('function'), throwsStateError);
@@ -57,7 +81,7 @@ void main() {
       );
 
       await client.dispose();
-      final res = await client.invoke('function1');
+      final res = await client.invoke('function');
       expect(res.data, {'key': 'Hello World'});
     });
 
@@ -69,5 +93,65 @@ void main() {
             ['a', 'b', 'c'],
           ));
     });
+
+    group('body encoding', () {
+      test('integer properly encoded', () async {
+        await functionsCustomHttpClient.invoke('function', body: 42);
+
+        final req = customHttpClient.receivedRequests.last;
+        expect(req, isA<Request>());
+
+        req as Request;
+        expect(req.body, '42');
+        expect(req.headers["Content-Type"], contains("application/json"));
+      });
+
+      test('double is properly encoded', () async {
+        await functionsCustomHttpClient.invoke('function', body: 42.9);
+
+        final req = customHttpClient.receivedRequests.last;
+        expect(req, isA<Request>());
+
+        req as Request;
+        expect(req.body, '42.9');
+        expect(req.headers["Content-Type"], contains("application/json"));
+      });
+
+      test('string is properly encoded', () async {
+        await functionsCustomHttpClient.invoke('function', body: 'ExampleText');
+
+        final req = customHttpClient.receivedRequests.last;
+        expect(req, isA<Request>());
+
+        req as Request;
+        expect(req.body, 'ExampleText');
+        expect(req.headers["Content-Type"], contains("text/plain"));
+      });
+
+      test('list is properly encoded', () async {
+        await functionsCustomHttpClient.invoke('function', body: [1, 2, 3]);
+
+        final req = customHttpClient.receivedRequests.last;
+        expect(req, isA<Request>());
+
+        req as Request;
+        expect(req.body, '[1,2,3]');
+        expect(req.headers["Content-Type"], contains("application/json"));
+      });
+
+      test('map is properly encoded', () async {
+        await functionsCustomHttpClient.invoke(
+          'function',
+          body: {'thekey': 'thevalue'},
+        );
+
+        final req = customHttpClient.receivedRequests.last;
+        expect(req, isA<Request>());
+
+        req as Request;
+        expect(req.body, '{"thekey":"thevalue"}');
+        expect(req.headers["Content-Type"], contains("application/json"));
+      });
+    });
   });
 }