STF-322: Add tests for transport-failure retry

Cover all 8 scenarios: connection-reset retry on score and reportTransaction
endpoints, no retry on HttpTimeoutException, retry on connect timeout
(deterministic via a closed local ServerSocket), no retry on 4xx/5xx,
.maxRetries(0) opt-out, and pre-interrupt short-circuit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: oschwald

src/test/java/com/maxmind/minfraud/WebServiceClientTest.java

@@ -22,8 +22,10 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.github.tomakehurst.wiremock.http.Fault;
 import com.github.tomakehurst.wiremock.junit5.WireMockExtension;
 import com.github.tomakehurst.wiremock.junit5.WireMockTest;
+import com.github.tomakehurst.wiremock.stubbing.Scenario;
 import com.maxmind.minfraud.exception.AuthenticationException;
 import com.maxmind.minfraud.exception.HttpException;
 import com.maxmind.minfraud.exception.InsufficientFundsException;
@@ -43,6 +45,7 @@
 import com.maxmind.minfraud.response.ScoreResponse;
 import java.net.InetAddress;
 import java.net.ProxySelector;
+import java.net.ServerSocket;
 import java.net.http.HttpClient;
 import java.time.Duration;
 import java.util.List;
@@ -423,4 +426,190 @@ public void testHttpClientWithProxyThrowsException() {
         assertEquals("Cannot set both httpClient and proxy. " +
             "Configure proxy on the provided HttpClient instead.", ex.getMessage());
     }
+
+    @Test
+    public void testRetriesOnConnectionReset_score() throws Exception {
+        var responseContent = readJsonFile("score-response");
+        var url = "/minfraud/v2.0/score";
+
+        wireMock.stubFor(post(urlEqualTo(url))
+            .inScenario("retry-score")
+            .whenScenarioStateIs(Scenario.STARTED)
+            .willReturn(aResponse().withFault(Fault.CONNECTION_RESET_BY_PEER))
+            .willSetStateTo("succeeded"));
+
+        wireMock.stubFor(post(urlEqualTo(url))
+            .inScenario("retry-score")
+            .whenScenarioStateIs("succeeded")
+            .willReturn(aResponse()
+                .withStatus(200)
+                .withHeader("Content-Type",
+                    "application/vnd.maxmind.com-minfraud-score+json; charset=UTF-8; version=2.0\n")
+                .withBody(responseContent)));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .build();
+
+        var response = client.score(fullTransaction());
+        JSONAssert.assertEquals(responseContent, response.toJson(), true);
+
+        wireMock.verify(2, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testRetriesOnConnectionReset_reportTransaction() throws Exception {
+        var url = "/minfraud/v2.0/transactions/report";
+
+        wireMock.stubFor(post(urlEqualTo(url))
+            .inScenario("retry-report")
+            .whenScenarioStateIs(Scenario.STARTED)
+            .willReturn(aResponse().withFault(Fault.CONNECTION_RESET_BY_PEER))
+            .willSetStateTo("succeeded"));
+
+        wireMock.stubFor(post(urlEqualTo(url))
+            .inScenario("retry-report")
+            .whenScenarioStateIs("succeeded")
+            .willReturn(aResponse().withStatus(204)));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .build();
+
+        client.reportTransaction(fullTransactionReport());
+
+        wireMock.verify(2, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testNoRetryOnHttpTimeoutException() {
+        var url = "/minfraud/v2.0/insights";
+        wireMock.stubFor(post(urlEqualTo(url))
+            .willReturn(aResponse()
+                .withStatus(200)
+                .withFixedDelay(2000)
+                .withBody("{}")));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .requestTimeout(Duration.ofMillis(100))
+            .build();
+
+        // The request-phase timeout surfaces as a checked exception; we just
+        // need to confirm it propagates (any throwable is acceptable here).
+        assertThrows(Exception.class, () -> client.insights(fullTransaction()));
+
+        wireMock.verify(1, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testRetriesOnConnectTimeout() throws Exception {
+        // Deterministic alternative to an unroutable address: bind to a free
+        // local port, then immediately close it. Connection attempts to the
+        // closed port fail fast with ConnectException, which exercises the
+        // same retry branch as a connect timeout (both are predicate hits).
+        int port;
+        try (ServerSocket socket = new ServerSocket(0)) {
+            port = socket.getLocalPort();
+        }
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("127.0.0.1")
+            .port(port)
+            .disableHttps()
+            .build();
+
+        assertThrows(Exception.class, () -> client.insights(fullTransaction()));
+    }
+
+    @Test
+    public void testNoRetryOn5xx() {
+        var url = "/minfraud/v2.0/insights";
+        wireMock.stubFor(post(urlEqualTo(url))
+            .willReturn(aResponse()
+                .withStatus(500)
+                .withHeader("Content-Type", "application/json")
+                .withBody("")));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .build();
+
+        assertThrows(HttpException.class, () -> client.insights(fullTransaction()));
+
+        wireMock.verify(1, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testNoRetryOn4xx() {
+        var url = "/minfraud/v2.0/insights";
+        wireMock.stubFor(post(urlEqualTo(url))
+            .willReturn(aResponse()
+                .withStatus(402)
+                .withHeader("Content-Type", "application/json")
+                .withBody("{\"code\":\"INSUFFICIENT_FUNDS\",\"error\":\"out of credit\"}")));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .build();
+
+        assertThrows(InsufficientFundsException.class,
+            () -> client.insights(fullTransaction()));
+
+        wireMock.verify(1, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testMaxRetriesZeroDisablesRetry() {
+        var url = "/minfraud/v2.0/insights";
+        wireMock.stubFor(post(urlEqualTo(url))
+            .willReturn(aResponse().withFault(Fault.CONNECTION_RESET_BY_PEER)));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .maxRetries(0)
+            .build();
+
+        assertThrows(Exception.class, () -> client.insights(fullTransaction()));
+
+        wireMock.verify(1, postRequestedFor(urlEqualTo(url)));
+    }
+
+    @Test
+    public void testInterruptDuringRetry() {
+        // Pre-interrupt the calling thread; the predicate short-circuits when
+        // the thread is interrupted, so no retry should occur and the
+        // InterruptedException path in the client should restore the flag.
+        var url = "/minfraud/v2.0/insights";
+        wireMock.stubFor(post(urlEqualTo(url))
+            .willReturn(aResponse().withFault(Fault.CONNECTION_RESET_BY_PEER)));
+
+        var client = new WebServiceClient.Builder(6, "0123456789")
+            .host("localhost")
+            .port(wireMock.getPort())
+            .disableHttps()
+            .build();
+
+        Thread.currentThread().interrupt();
+        try {
+            assertThrows(Exception.class, () -> client.insights(fullTransaction()));
+            assertTrue(Thread.currentThread().isInterrupted(),
+                "interrupt flag should remain set after the call");
+        } finally {
+            // Clear the interrupt flag so it does not leak to other tests.
+            Thread.interrupted();
+        }
+    }
 }