let reader read MVEL rules from String

easy-rules-mvel/src/main/java/org/jeasy/rules/mvel/MVELRuleDefinitionReader.java

@@ -42,6 +42,12 @@ class MVELRuleDefinitionReader {
         return createRuleDefinitionFrom(map);
     }
 
+    MVELRuleDefinition read(String descriptor) throws NullPointerException {
+        Object object = yaml.load(descriptor);
+        Map<String, Object> map = (Map<String, Object>) object;
+        return createRuleDefinitionFrom(map);
+    }
+
     private static MVELRuleDefinition createRuleDefinitionFrom(Map<String, Object> map) {
         MVELRuleDefinition ruleDefinition = new MVELRuleDefinition();
         ruleDefinition.setName((String) map.get("name"));

easy-rules-mvel/src/test/java/org/jeasy/rules/mvel/MVELRuleDefinitionReaderTest.java

@@ -26,6 +26,8 @@ package org.jeasy.rules.mvel;
 import org.junit.Test;
 
 import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.Collections;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -51,4 +53,22 @@ public class MVELRuleDefinitionReaderTest {
         assertThat(adultRuleDefinition.getActions()).isEqualTo(Collections.singletonList("person.setAdult(true);"));
     }
 
+    @Test
+    public void testRuleDefinitionReadingFromString() throws Exception {
+        // given
+        String adultRuleDescriptor = new String(Files.readAllBytes(Paths.get("src/test/resources/adult-rule.yml")));
+
+        // when
+        MVELRuleDefinition adultRuleDefinition = ruleDefinitionReader.read(adultRuleDescriptor);
+
+        // then
+        assertThat(adultRuleDefinition).isNotNull();
+        assertThat(adultRuleDefinition.getName()).isEqualTo("adult rule");
+        assertThat(adultRuleDefinition.getDescription()).isEqualTo("when age is greater then 18, then mark as adult");
+        assertThat(adultRuleDefinition.getPriority()).isEqualTo(1);
+        assertThat(adultRuleDefinition.getCondition()).isEqualTo("person.age > 18");
+        assertThat(adultRuleDefinition.getActions()).isEqualTo(Collections.singletonList("person.setAdult(true);"));
+    }
+
+
 }