Added tests for Easy::Tag.

README.adoc

@@ -412,7 +412,7 @@ strings and you can use unsupported fields in an `Entity` by converting it to
 * [x] Results
 * [x] Status
 * [ ] ScheduledStatus
-* [ ] Tag
+* [x] Tag
 * [ ] Token
 
 === glitch-soc API

tests/entities/test_tag.cpp

@@ -0,0 +1,85 @@
+/*  This file is part of mastodon-cpp.
+ *  Copyright © 2019 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <exception>
+#include <string>
+#include <chrono>
+#include <catch.hpp>
+#include "easy/entities/tag.hpp"
+#include "easy/easy.hpp"
+
+using std::string;
+using std::chrono::system_clock;
+
+using namespace Mastodon;
+
+SCENARIO ("Easy::Tag works as intended", "[entity]")
+{
+    GIVEN ("An Easy::Tag object")
+    {
+        Easy::Tag tag;
+        bool exception = false;
+
+        WHEN ("It is initialized with valid tag data")
+        {
+            const string data =
+                "{\"name\":\"testtag\","
+                "\"url\":\"https://example.com/tag/testtag\","
+                "\"history\":"
+                  "[{\"day\":\"1565579400\",\"uses\":4,\"accounts\":2}]}";
+
+            try
+            {
+                tag.from_string(data);
+            }
+            catch (const std::exception &e)
+            {
+                exception = true;
+            }
+
+            THEN ("No exception is thrown")
+                AND_THEN ("Tag are valid")
+                AND_THEN ("The attributes are set to the right values")
+            {
+                REQUIRE_FALSE(exception);
+                REQUIRE(tag.valid());
+                REQUIRE(tag.name() == "testtag");
+                REQUIRE(tag.history()[0].uses() == 4);
+            }
+        }
+
+        WHEN ("It is initialized with an empty string")
+        {
+            try
+            {
+                tag.from_string("");
+            }
+            catch (const std::exception &e)
+            {
+                exception = true;
+            }
+
+            THEN ("No exception is thrown")
+                AND_THEN ("It is not valid")
+                AND_THEN ("history is empty")
+            {
+                REQUIRE_FALSE(exception);
+                REQUIRE_FALSE(tag.valid());
+                REQUIRE(tag.history().size() == 0);
+            }
+        }
+    }
+}