Add RefreshScopeHealthIndicator

Repots DOWN if there are errors in RefreshScope or
ConfigurationProperties rebinding, N.B. RefreshScope instantiates
its beans lazily after a refresh by default, so you won't see an
error until the bean is used.

Fixes gh-85

spring-cloud-context/src/test/java/org/springframework/cloud/health/RefreshScopeHealthIndicatorTests.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2013-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.health;
+
+import java.util.Collections;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mockito;
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder;
+import org.springframework.cloud.context.scope.refresh.RefreshScope;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+
+/**
+ * @author Dave Syer
+ */
+public class RefreshScopeHealthIndicatorTests {
+
+	private ConfigurationPropertiesRebinder rebinder = Mockito
+			.mock(ConfigurationPropertiesRebinder.class);
+	private RefreshScope scope = Mockito.mock(RefreshScope.class);
+	private RefreshScopeHealthIndicator indicator = new RefreshScopeHealthIndicator(
+			this.scope, this.rebinder);
+
+	@Before
+	public void init() {
+		when(this.rebinder.getErrors())
+				.thenReturn(Collections.<String, Exception> emptyMap());
+		when(this.scope.getErrors())
+				.thenReturn(Collections.<String, Exception> emptyMap());
+	}
+
+	@Test
+	public void sunnyDay() {
+		assertEquals(Status.UP, this.indicator.health().getStatus());
+	}
+
+	@Test
+	public void binderError() {
+		when(this.rebinder.getErrors()).thenReturn(Collections
+				.<String, Exception> singletonMap("foo", new RuntimeException("FOO")));
+		assertEquals(Status.DOWN, this.indicator.health().getStatus());
+	}
+
+	@Test
+	public void scopeError() {
+		when(this.scope.getErrors()).thenReturn(Collections
+				.<String, Exception> singletonMap("foo", new RuntimeException("FOO")));
+		assertEquals(Status.DOWN, this.indicator.health().getStatus());
+	}
+
+	@Test
+	public void bothError() {
+		when(this.rebinder.getErrors()).thenReturn(Collections
+				.<String, Exception> singletonMap("foo", new RuntimeException("FOO")));
+		when(this.scope.getErrors()).thenReturn(Collections
+				.<String, Exception> singletonMap("bar", new RuntimeException("BAR")));
+		assertEquals(Status.DOWN, this.indicator.health().getStatus());
+	}
+
+}