Flesh out the repository with example and tests

tests/json_test.c

@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <string.h>
+
+#include <unity.h>
+
+#include <json.h>
+
+static FILE* tmp = nullptr;
+static char buffer[256];
+
+static Json json;
+
+void setUp()
+{
+    tmp = tmpfile();
+    TEST_ASSERT_NOT_NULL(tmp);
+
+    json = json_init(tmp, MINIFIED);
+}
+
+void tearDown()
+{
+    json_free(&json);
+
+    if (tmp) {
+        fclose(tmp);
+        tmp = nullptr;
+    }
+}
+
+void test_json_add_string()
+{
+    json_add_string(&json, "string");
+    fflush(tmp);
+    rewind(tmp);
+
+    char buffer[256];
+    auto n = fread(buffer, 1, sizeof(buffer) - 1, tmp);
+    buffer[n] = '\0';
+
+    TEST_ASSERT_EQUAL_STRING("\"string\"", buffer);
+}
+
+int main()
+{
+    UNITY_BEGIN();
+    {
+        RUN_TEST(test_json_add_string);
+    }
+    return UNITY_END();
+}
+