Add ExpectedCount#never()

Issue: SPR-15168

spring-test/src/main/java/org/springframework/test/web/client/DefaultRequestExpectation.java

@@ -139,6 +139,7 @@ public class DefaultRequestExpectation implements RequestExpectation {
 		}
 
 		public boolean isSatisfied() {
+			// Only validate min count since max count is checked on every request...
 			return (getMatchedRequestCount() >= getExpectedCount().getMinCount());
 		}
 	}

spring-test/src/main/java/org/springframework/test/web/client/ExpectedCount.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -31,6 +31,7 @@ import org.springframework.util.Assert;
  * min(2)
  * max(4)
  * between(2, 4)
+ * never()
  * </pre>
  *
  * @author Rossen Stoyanchev
@@ -48,7 +49,7 @@ public class ExpectedCount {
 	 * See static factory methods in this class.
 	 */
 	private ExpectedCount(int minCount, int maxCount) {
-		Assert.isTrue(minCount >= 1, "minCount >= 0 is required");
+		Assert.isTrue(minCount >= 0, "minCount >= 0 is required");
 		Assert.isTrue(maxCount >= minCount, "maxCount >= minCount is required");
 		this.minCount = minCount;
 		this.maxCount = maxCount;
@@ -108,6 +109,14 @@ public class ExpectedCount {
 		return new ExpectedCount(1, max);
 	}
 
+	/**
+	 * No calls expected at all, i.e. min=0 and max=0.
+	 * @since 4.3.6
+	 */
+	public static ExpectedCount never() {
+		return new ExpectedCount(0, 0);
+	}
+
 	/**
 	 * Between {@code min} and {@code max} number of times.
 	 */

spring-test/src/test/java/org/springframework/test/web/client/samples/SampleTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -28,6 +28,8 @@ import org.springframework.web.client.RestTemplate;
 
 import static org.junit.Assert.assertTrue;
 import static org.springframework.test.web.client.ExpectedCount.manyTimes;
+import static org.springframework.test.web.client.ExpectedCount.never;
+import static org.springframework.test.web.client.ExpectedCount.once;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.method;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
 import static org.springframework.test.web.client.response.MockRestResponseCreators.withSuccess;
@@ -92,6 +94,35 @@ public class SampleTests {
 		this.mockServer.verify();
 	}
 
+	@Test
+	public void expectNever() throws Exception {
+
+		String responseBody = "{\"name\" : \"Ludwig van Beethoven\", \"someDouble\" : \"1.6035\"}";
+
+		this.mockServer.expect(once(), requestTo("/composers/42")).andExpect(method(HttpMethod.GET))
+				.andRespond(withSuccess(responseBody, MediaType.APPLICATION_JSON));
+		this.mockServer.expect(never(), requestTo("/composers/43")).andExpect(method(HttpMethod.GET))
+				.andRespond(withSuccess(responseBody, MediaType.APPLICATION_JSON));
+
+		this.restTemplate.getForObject("/composers/{id}", Person.class, 42);
+
+		this.mockServer.verify();
+	}
+
+	@Test(expected = AssertionError.class)
+	public void expectNeverViolated() throws Exception {
+
+		String responseBody = "{\"name\" : \"Ludwig van Beethoven\", \"someDouble\" : \"1.6035\"}";
+
+		this.mockServer.expect(once(), requestTo("/composers/42")).andExpect(method(HttpMethod.GET))
+				.andRespond(withSuccess(responseBody, MediaType.APPLICATION_JSON));
+		this.mockServer.expect(never(), requestTo("/composers/43")).andExpect(method(HttpMethod.GET))
+				.andRespond(withSuccess(responseBody, MediaType.APPLICATION_JSON));
+
+		this.restTemplate.getForObject("/composers/{id}", Person.class, 42);
+		this.restTemplate.getForObject("/composers/{id}", Person.class, 43);
+	}
+
 	@Test
 	public void performGetWithResponseBodyFromFile() throws Exception {