Add problem-details: global exception handling with RFC 9457

Companion code for "Global Exception Handling with ProblemDetail (RFC 9457) in Spring Boot 4". Thirteen failures under five handling setups (Boot defaults, the Boot flag, a ResponseEntityExceptionHandler advice, advice plus an ErrorController, a catch-all ordered first), validation errors, i18n, content negotiation, Security's 401/403, silent 500s and decoding on the client. 16 tests pin the behaviour. Co-Authored-By: Claude Opus 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01C3TETMrqVUWeFkNtz3Jbo3
2026-09-11 17:12:22 +00:00
parent a065696478
commit 926250e1a9
63 changed files with 2414 additions and 0 deletions
@@ -0,0 +1,100 @@
+package com.ankurm.problems;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.test.context.ActiveProfiles;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * The contract of the recommended setup (profiles advice + errors): every failure, including the
+ * ones produced outside Spring MVC, is application/problem+json with the right status.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+@ActiveProfiles({"advice", "errors"})
+class AdviceContractTest {
+
+    private static final String PROBLEM = "application/problem+json";
+
+    @LocalServerPort
+    int port;
+
+    @Test
+    void domainExceptionIs404WithStableType() throws Exception {
+        Http.Response r = Http.get(port, "/orders/999");
+        assertThat(r.status()).isEqualTo(404);
+        assertThat(r.contentType()).isEqualTo(PROBLEM);
+        assertThat(r.body()).contains("\"type\":\"https://ankurm.com/problems/order-not-found\"")
+                .contains("\"orderId\":999")
+                .contains("\"instance\":\"/orders/999\"");
+    }
+
+    @Test
+    void validationListsEveryViolationWithAPointer() throws Exception {
+        Http.Response r = Http.send(port, "POST", "/orders", "{\"sku\":\"\",\"quantity\":0,\"customerEmail\":\"nope\"}");
+        assertThat(r.status()).isEqualTo(400);
+        assertThat(r.contentType()).isEqualTo(PROBLEM);
+        // Order of the three is not stable between runs - assert membership, not position.
+        assertThat(r.body()).contains("\"pointer\":\"#/sku\"", "\"pointer\":\"#/quantity\"",
+                "\"pointer\":\"#/customerEmail\"");
+    }
+
+    @Test
+    void unexpectedExceptionDoesNotLeakItsMessage() throws Exception {
+        Http.Response r = Http.get(port, "/orders/boom");
+        assertThat(r.status()).isEqualTo(500);
+        assertThat(r.contentType()).isEqualTo(PROBLEM);
+        assertThat(r.body()).contains("\"errorId\":").doesNotContain("jdbc:").doesNotContain("orders_rw");
+    }
+
+    @Test
+    void filterExceptionReachesTheErrorControllerNotTheAdvice() throws Exception {
+        Http.Response r = Http.get(port, "/orders/1", "X-Tenant", "BAD!");
+        assertThat(r.status()).isEqualTo(500);
+        assertThat(r.contentType()).isEqualTo(PROBLEM);
+        assertThat(r.body()).doesNotContain("X-Tenant").doesNotContain("errorId");
+    }
+
+    @Test
+    void securityResponsesAreProblemsToo() throws Exception {
+        Http.Response anonymous = Http.get(port, "/admin/orders");
+        assertThat(anonymous.status()).isEqualTo(401);
+        assertThat(anonymous.contentType()).isEqualTo(PROBLEM);
+        assertThat(anonymous.headers().firstValue("WWW-Authenticate")).hasValue("Basic realm=\"orders\"");
+
+        Http.Response user = Http.get(port, "/admin/orders", "Authorization", Http.basic("user", "user"));
+        assertThat(user.status()).isEqualTo(403);
+        assertThat(user.contentType()).isEqualTo(PROBLEM);
+    }
+
+    @Test
+    void anAcceptOfApplicationXmlStillGetsJson() throws Exception {
+        // application/xml is not compatible with application/problem+xml, so the error falls back
+        // to problem+json - while a successful response to the same Accept header is XML.
+        assertThat(Http.get(port, "/orders/1", "Accept", "application/xml").contentType())
+                .startsWith("application/xml");
+        assertThat(Http.get(port, "/orders/999", "Accept", "application/xml").contentType())
+                .isEqualTo(PROBLEM);
+        assertThat(Http.get(port, "/orders/999", "Accept", "application/problem+xml").contentType())
+                .isEqualTo("application/problem+xml");
+    }
+
+    @Test
+    void anUnsatisfiableAcceptDoesNotTurnTheErrorInto406() throws Exception {
+        Http.Response r = Http.get(port, "/orders/999", "Accept", "image/png");
+        assertThat(r.status()).isEqualTo(404);
+        assertThat(r.contentType()).isEqualTo(PROBLEM);
+    }
+
+    @Test
+    void messageSourceOverridesTitleAndDetailPerLocale() throws Exception {
+        String body = "{\"sku\":\"SKU-2\",\"quantity\":3,\"customerEmail\":\"[email protected]\"}";
+        assertThat(Http.send(port, "POST", "/orders", body).body())
+                .contains("\"title\":\"Out of stock\"")
+                .contains("\"detail\":\"Only 0 unit(s) of SKU-2 are available.\"");
+        assertThat(Http.send(port, "POST", "/orders", body, "Accept-Language", "de").body())
+                .contains("\"title\":\"Nicht vorrätig\"");
+    }
+}