test: add tests for Content class

test/core/content_test.dart

@@ -0,0 +1,61 @@
+// Copyright 2023 Contributors to the Eclipse Foundation. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import 'dart:convert';
+
+import 'package:dart_wot/dart_wot.dart';
+import 'package:dart_wot/src/core/content.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('Content should', () {
+    group('be able to be instantiated using fromInteractionInput() with', () {
+      test('null', () async {
+        final contentSerdes = ContentSerdes();
+        final content = Content.fromInteractionInput(
+          null,
+          'application/json',
+          contentSerdes,
+          null,
+        );
+
+        expect(await content.body.isEmpty, isTrue);
+      });
+
+      test('a DataSchemaValueInput', () async {
+        final contentSerdes = ContentSerdes();
+        const inputValue = 'foo';
+        final input =
+            DataSchemaValueInput(DataSchemaValue.fromString(inputValue));
+
+        final content = Content.fromInteractionInput(
+          input,
+          'application/json',
+          contentSerdes,
+          null,
+        );
+
+        expect(await content.toByteList(), [34, 102, 111, 111, 34]);
+      });
+
+      test('a StreamInput', () async {
+        final contentSerdes = ContentSerdes();
+        const inputValue = '"foo"';
+        final byteList = [utf8.encode(inputValue)];
+        final input = StreamInput(Stream.fromIterable(byteList));
+
+        final content = Content.fromInteractionInput(
+          input,
+          'application/json',
+          contentSerdes,
+          null,
+        );
+
+        expect(await content.toByteList(), [34, 102, 111, 111, 34]);
+      });
+    });
+  });
+}