Put FIRST and MERGE strategies into new test class

owner/src/test/java/org/aeonbits/owner/loaders/SystemLoaderTest.java

@@ -0,0 +1,149 @@
+package org.aeonbits.owner.loaders;
+
+import static org.aeonbits.owner.Config.LoadType.FIRST;
+import static org.aeonbits.owner.Config.LoadType.MERGE;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.aeonbits.owner.Config;
+import org.aeonbits.owner.ConfigFactory;
+import org.junit.After;
+import org.junit.Test;
+
+/**
+ * Date: Mar 31, 2015 Copyright 2015 Motif Investing, Inc.
+ *
+ * @author ting-kuanwu
+ */
+public class SystemLoaderTest {
+
+    private SystemPropertiesHelper systemPropertiesHelper = new SystemPropertiesHelper();
+
+    @Config.Sources({"system:properties",
+            "system:env"})
+    @Config.LoadPolicy(FIRST)
+    public static interface FirstConfig extends Config {
+        @DefaultValue("this should be ignored")
+        String foo();
+
+        @DefaultValue("this should be ignored")
+        String bar();
+
+        @DefaultValue("user.home")
+        String userHome();
+
+        @Key("PATH")
+        String path();
+
+        String nullProp();
+
+        @DefaultValue("theDefaultValue")
+        String useDefault();
+    }
+
+    @Test
+    public void first_loadSystemProperties() {
+        systemPropertiesHelper.setProperty("foo", "FOO");
+        systemPropertiesHelper.setProperty("bar", "BAR");
+
+        FirstConfig config = ConfigFactory.create(FirstConfig.class);
+
+        assertEquals("FOO", config.foo());
+        assertEquals("BAR", config.bar());
+    }
+
+    @Test
+    public void first_nullProp() {
+        FirstConfig config = ConfigFactory.create(FirstConfig.class);
+        assertNull(config.nullProp());
+    }
+
+    @Test
+    public void first_loadSysPropFirst_ignoreEnvVars() {
+        FirstConfig config = ConfigFactory.create(FirstConfig.class);
+        assertNull(config.path());
+    }
+
+    @Config.Sources({"system:properties",
+            "system:env"})
+    @Config.LoadPolicy(MERGE)
+    public static interface MergeConfig extends Config {
+        @DefaultValue("this should be ignored")
+        String foo();
+
+        @DefaultValue("this should be ignored")
+        String bar();
+
+        @DefaultValue("user.home")
+        String userHome();
+
+        @Key("PATH")
+        String path();
+
+        String nullProp();
+
+        @DefaultValue("theDefaultValue")
+        String useDefault();
+    }
+
+    @Test
+    public void merge_loadSystemProperties() {
+        systemPropertiesHelper.setProperty("foo", "FOO");
+        systemPropertiesHelper.setProperty("bar", "BAR");
+
+        MergeConfig config = ConfigFactory.create(MergeConfig.class);
+
+        assertEquals("FOO", config.foo());
+        assertEquals("BAR", config.bar());
+    }
+
+    @Test
+    public void merge_includeDefaultSystemProperties() {
+        MergeConfig config = ConfigFactory.create(MergeConfig.class);
+        assertNotNull(config.userHome());
+    }
+
+    @Test
+    public void merge_defaultValueFromConfig() {
+        MergeConfig config = ConfigFactory.create(MergeConfig.class);
+        assertEquals("theDefaultValue", config.useDefault());
+    }
+
+    @Test
+    public void merge_nullProp() {
+        MergeConfig config = ConfigFactory.create(MergeConfig.class);
+        assertNull(config.nullProp());
+    }
+
+    @Test
+    public void merge_pathEnvVariable() {
+        MergeConfig config = ConfigFactory.create(MergeConfig.class);
+        assertNotNull(config.path());
+    }
+
+    @After
+    public void cleanSystemProperties() {
+        systemPropertiesHelper.cleanNonDefaultSysProps();
+    }
+
+    private class SystemPropertiesHelper {
+
+        private List<String> sysProps = new ArrayList<String>();
+
+        public void setProperty(String key, String val) {
+            System.setProperty(key, val);
+            sysProps.add(key);
+        }
+
+        public void cleanNonDefaultSysProps() {
+            for (String prop : sysProps) {
+                System.clearProperty(prop);
+            }
+            sysProps.clear();
+        }
+    }
+}