Provide a public API for determining a request's outcome

Closes gh-18150

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/http/OutcomeTests.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.actuate.metrics.http;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link Outcome}.
+ *
+ * @author Andy Wilkinson
+ */
+public class OutcomeTests {
+
+	@Test
+	void outcomeForInformationalStatusIsInformational() {
+		for (int status = 100; status < 200; status++) {
+			assertThat(Outcome.forStatus(status)).isEqualTo(Outcome.INFORMATIONAL);
+		}
+	}
+
+	@Test
+	void outcomeForSuccessStatusIsSuccess() {
+		for (int status = 200; status < 300; status++) {
+			assertThat(Outcome.forStatus(status)).isEqualTo(Outcome.SUCCESS);
+		}
+	}
+
+	@Test
+	void outcomeForRedirectionStatusIsRedirection() {
+		for (int status = 300; status < 400; status++) {
+			assertThat(Outcome.forStatus(status)).isEqualTo(Outcome.REDIRECTION);
+		}
+	}
+
+	@Test
+	void outcomeForClientErrorStatusIsClientError() {
+		for (int status = 400; status < 500; status++) {
+			assertThat(Outcome.forStatus(status)).isEqualTo(Outcome.CLIENT_ERROR);
+		}
+	}
+
+	@Test
+	void outcomeForServerErrorStatusIsServerError() {
+		for (int status = 500; status < 600; status++) {
+			assertThat(Outcome.forStatus(status)).isEqualTo(Outcome.SERVER_ERROR);
+		}
+	}
+
+	@Test
+	void outcomeForStatusBelowLowestKnownSeriesIsUnknown() {
+		assertThat(Outcome.forStatus(99)).isEqualTo(Outcome.UNKNOWN);
+	}
+
+	@Test
+	void outcomeForStatusAboveHighestKnownSeriesIsUnknown() {
+		assertThat(Outcome.forStatus(600)).isEqualTo(Outcome.UNKNOWN);
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/client/RestTemplateExchangeTagsTests.java

@@ -86,14 +86,6 @@ class RestTemplateExchangeTagsTests {
 		assertThat(tag.getValue()).isEqualTo("UNKNOWN");
 	}
 
-	@Test
-	void outcomeTagIsUnknownForCustomResponseStatus() throws Exception {
-		ClientHttpResponse response = mock(ClientHttpResponse.class);
-		given(response.getRawStatusCode()).willThrow(IllegalArgumentException.class);
-		Tag tag = RestTemplateExchangeTags.outcome(response);
-		assertThat(tag.getValue()).isEqualTo("UNKNOWN");
-	}
-
 	@Test
 	void outcomeTagIsClientErrorWhenResponseIsNonStandardInClientSeries() throws IOException {
 		ClientHttpResponse response = mock(ClientHttpResponse.class);