Extracted class StringBuilderTests

JsonGeneratorTests/StringBuilderTests.cpp

@@ -0,0 +1,80 @@
+#include "CppUnitTest.h"
+#include "StringBuilder.h"
+
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+
+namespace JsonGeneratorTests
+{
+	TEST_CLASS(StringBuilderTests)
+	{
+        char buffer[20];
+        Print* sb;
+        size_t returnValue;
+
+	public:
+		
+        TEST_METHOD_INITIALIZE(Initialize)
+        {
+            sb = new StringBuilder(buffer, sizeof(buffer));
+        }
+
+        TEST_METHOD(InitialState)
+        {
+            assertResultIs("");
+        }
+
+        TEST_METHOD(OverCapacity)
+        {
+            write("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+            assertReturns(19);
+            assertResultIs("ABCDEFGHIJKLMNOPQRS");
+
+            write("ABC");
+            assertReturns(0);
+            assertResultIs("ABCDEFGHIJKLMNOPQRS");
+        }
+
+        TEST_METHOD(EmptyString)
+        {
+            write("");
+
+            assertReturns(0);
+            assertResultIs("");
+        }
+
+        TEST_METHOD(OneString)
+        {
+            write("ABCD");
+            assertReturns(4);
+            assertResultIs("ABCD");
+        }
+
+        TEST_METHOD(TwoStrings)
+        {
+            write("ABCD");
+            assertReturns(4);
+
+            write("EFGH");
+            assertReturns(4);
+
+            assertResultIs("ABCDEFGH");
+        }
+
+    private:
+
+        void write(const char* value)
+        {
+            returnValue = sb->write(value);
+        }
+
+        void assertResultIs(const char* expected)
+        {
+            Assert::AreEqual(expected, buffer);
+        }
+
+        void assertReturns(size_t expected)
+        {
+            Assert::AreEqual(expected, returnValue);
+        }
+	};
+}