add Rules tests

easy-rules-core/src/test/java/org/jeasy/rules/api/RulesTest.java

@@ -0,0 +1,68 @@
+package org.jeasy.rules.api;
+
+import org.jeasy.rules.annotation.Action;
+import org.jeasy.rules.annotation.Condition;
+import org.jeasy.rules.core.BasicRule;
+import org.junit.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RulesTest {
+
+    private Rules rules = new Rules();
+
+    @Test
+    public void register() throws Exception {
+        rules.register(new DummyRule());
+
+        assertThat(rules).hasSize(1);
+    }
+
+    @Test
+    public void rulesMustHaveUniqueName() throws Exception {
+        Rule r1 = new BasicRule("rule");
+        Rule r2 = new BasicRule("rule");
+        Set<Rule> ruleSet = new HashSet<>();
+        ruleSet.add(r1);
+        ruleSet.add(r2);
+
+        rules = new Rules(ruleSet);
+
+        assertThat(rules).hasSize(1);
+    }
+
+    @Test
+    public void unregister() throws Exception {
+        DummyRule rule = new DummyRule();
+        rules.register(rule);
+        rules.unregister(rule);
+
+        assertThat(rules).isEmpty();
+    }
+
+    @Test
+    public void isEmpty() throws Exception {
+        assertThat(rules.isEmpty()).isTrue();
+    }
+
+    @Test
+    public void clear() throws Exception {
+        rules.register(new DummyRule());
+        rules.clear();
+
+        assertThat(rules).isEmpty();
+    }
+
+    @org.jeasy.rules.annotation.Rule
+    class DummyRule {
+        @Condition
+        public boolean when() { return true; }
+
+        @Action
+        public void then() { }
+    }
+
+}