Introduce simplified Rest API builder (for replacing Jax-rs ressources)

1 files changed, 133 insertions, 0 deletions

diff --git a/container-core/src/test/java/com/yahoo/restapi/RestApiImplTest.java b/container-core/src/test/java/com/yahoo/restapi/RestApiImplTest.java
new file mode 100644
index 00000000000..628c25b23db
--- /dev/null
+++ b/container-core/src/test/java/com/yahoo/restapi/RestApiImplTest.java
@@ -0,0 +1,133 @@
+package com.yahoo.restapi;// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.yahoo.container.jdisc.HttpRequest;
+import com.yahoo.container.jdisc.HttpResponse;
+import com.yahoo.test.json.JsonTestHelper;
+import com.yahoo.yolean.Exceptions;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static com.yahoo.jdisc.http.HttpRequest.Method;
+import static com.yahoo.restapi.RestApi.route;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * @author bjorncs
+ */
+class RestApiImplTest {
+
+    @Test
+    void routes_requests_to_correct_handler() {
+        RestApi restApi = RestApi.builder()
+                .addRoute(route("/api1/{*}").get(ctx -> new MessageResponse("get-method-response")))
+                .addRoute(route("/api2/{*}").post(ctx -> new MessageResponse("post-method-response")))
+                .setDefaultRoute(route("{*}").defaultHandler(ctx -> ErrorResponse.notFoundError("default-method-response")))
+                .build();
+        verifyJsonResponse(restApi, Method.GET, "/api1/subpath", null, 200, "{\"message\":\"get-method-response\"}");
+        verifyJsonResponse(restApi, Method.POST, "/api1/subpath", "{}", 405, null);
+        verifyJsonResponse(restApi, Method.GET, "/api2/subpath", null, 405, null);
+        verifyJsonResponse(restApi, Method.POST, "/api2/subpath", "{}", 200, "{\"message\":\"post-method-response\"}");
+        verifyJsonResponse(restApi, Method.PUT, "/api2/subpath", "{}", 405, null);
+        verifyJsonResponse(restApi, Method.GET, "/unknown/subpath", null, 404, "{\"error-code\":\"NOT_FOUND\",\"message\":\"default-method-response\"}");
+        verifyJsonResponse(restApi, Method.DELETE, "/unknown/subpath", "{}", 404, "{\"error-code\":\"NOT_FOUND\",\"message\":\"default-method-response\"}");
+    }
+
+    @Test
+    void executes_filters_and_handler_in_correct_order() {
+        List<String> actualEvaluationOrdering = new ArrayList<>();
+        RestApi.MethodHandler<HttpResponse> handler = context -> {
+            actualEvaluationOrdering.add("handler");
+            return new MessageResponse("get-method-response");
+        };
+        class NamedTestFilter implements RestApi.Filter {
+            final String name;
+            NamedTestFilter(String name) { this.name = name; }
+
+            @Override
+            public HttpResponse filterRequest(RestApi.FilterContext context) {
+                actualEvaluationOrdering.add("pre-" + name);
+                HttpResponse response = context.executeNext();
+                actualEvaluationOrdering.add("post-" + name);
+                return response;
+            }
+        }
+        RestApi restApi = RestApi.builder()
+                .setDefaultRoute(route("{*}")
+                        .defaultHandler(handler)
+                        .addFilter(new NamedTestFilter("route-filter-1"))
+                        .addFilter(new NamedTestFilter("route-filter-2")))
+                .addFilter(new NamedTestFilter("global-filter-1"))
+                .addFilter(new NamedTestFilter("global-filter-2"))
+                .build();
+        verifyJsonResponse(restApi, Method.GET, "/", null, 200, "{\"message\":\"get-method-response\"}");
+        List<String> expectedOrdering = List.of(
+                "pre-global-filter-1", "pre-global-filter-2", "pre-route-filter-1", "pre-route-filter-2",
+                "handler",
+                "post-route-filter-2", "post-route-filter-1", "post-global-filter-2", "post-global-filter-1");
+        assertEquals(expectedOrdering, actualEvaluationOrdering);
+    }
+
+    @SuppressWarnings("divzero")
+    @Test
+    void handles_custom_response_and_exception_mapper() {
+        RestApi restApi = RestApi.builder()
+                .disableDefaultExceptionMappers()
+                .disableDefaultResponseMappers()
+                .addRoute(route("/long").get(ctx -> 123456L))
+                .addRoute(route("/exception").get(ctx -> 123L / 0L))
+                .addResponseMapper(Long.class, (entity, ctx) -> new MessageResponse("long value is " + entity))
+                .addExceptionMapper(ArithmeticException.class, (exception, ctx) -> ErrorResponse.internalServerError("oops division by zero"))
+                .build();
+        verifyJsonResponse(restApi, Method.GET, "/long", null, 200, "{\"message\":\"long value is 123456\"}");
+        verifyJsonResponse(restApi, Method.GET, "/exception", null, 500, "{\"message\":\"oops division by zero\", \"error-code\":\"INTERNAL_SERVER_ERROR\"}");
+    }
+
+    @Test
+    void method_handler_can_consume_and_produce_json() {
+        RestApi restApi = RestApi.builder()
+                .addRoute(route("/api").post(
+                        ctx -> {
+                            try {
+                                return ctx.requestContent().get().consumeJacksonEntity(TestEntity.class);
+                            } catch (IOException e) {
+                                throw new UncheckedIOException(e);
+                            }
+                        }))
+                .build();
+        String rawJson = "{\"mystring\":\"my-string-value\", \"myinstant\":\"2000-01-01T00:00:00Z\"}";
+        verifyJsonResponse(restApi, Method.POST, "/api", rawJson, 200, rawJson);
+    }
+
+    private static void verifyJsonResponse(RestApi restApi, Method method, String path, String requestContent, int expectedStatusCode, String expectedJson) {
+        HttpRequest testRequest = requestContent != null ?
+                HttpRequest.createTestRequest(
+                        path, method,
+                        new ByteArrayInputStream(requestContent.getBytes(StandardCharsets.UTF_8)),
+                        Map.of("Content-Type", "application/json")) :
+                HttpRequest.createTestRequest(path, method);
+        HttpResponse response = restApi.handleRequest(testRequest);
+        assertEquals(expectedStatusCode, response.getStatus());
+        if (expectedJson != null) {
+            assertEquals("application/json", response.getContentType());
+            var outputStream = new ByteArrayOutputStream();
+            Exceptions.uncheck(() -> response.render(outputStream));
+            String content = outputStream.toString(StandardCharsets.UTF_8);
+            JsonTestHelper.assertJsonEquals(content, expectedJson);
+        }
+    }
+
+    public static class TestEntity implements RestApi.JacksonRequestEntity, RestApi.JacksonResponseEntity {
+        @JsonProperty("mystring") public String stringValue;
+        @JsonProperty("myinstant") public Instant instantValue;
+    }
+}
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