feat: Add gRPC exmaple using provider state injected values with meta…

…data

examples/gRPC/provider-states/consumer-jvm/src/test/java/io/pact/example/grpc/consumer/PactConsumerTest.java

@@ -16,14 +16,18 @@
 import com.google.protobuf.InvalidProtocolBufferException;
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
+import io.grpc.Metadata;
+import io.grpc.stub.MetadataUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
 
 import static area_calculator.CalculatorGrpc.newBlockingStub;
 import static au.com.dius.pact.consumer.dsl.PactBuilder.filePath;
+import static io.grpc.Metadata.ASCII_STRING_MARSHALLER;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 
@@ -48,6 +52,10 @@ V4Pact calculateRectangleArea(PactBuilder builder) {
               "width", "matching(number, fromProviderState('${rectangleWidth}', 3))"
           )),
 
+          "requestMetadata", Map.of(
+            "Auth", "matching(equalTo, fromProviderState('${Auth}', 'AST00004'))"
+          ),
+
         "response", List.of(
             Map.of(
               "value", "matching(number, 12)"
@@ -61,8 +69,15 @@ V4Pact calculateRectangleArea(PactBuilder builder) {
   @PactTestFor(pactMethod = "calculateRectangleArea")
   @MockServerConfig(implementation = MockServerImplementation.Plugin, registryEntry = "protobuf/transport/grpc")
   void calculateRectangleArea(MockServer mockServer, V4Interaction.SynchronousMessages interaction) throws InvalidProtocolBufferException {
+    io.grpc.Metadata.Key<String> authKey = io.grpc.Metadata.Key.of("Auth", ASCII_STRING_MARSHALLER);
+    io.grpc.Metadata metadata = new io.grpc.Metadata();
+    metadata.put(authKey, "AST00004");
+    AtomicReference<Metadata> headers = new AtomicReference<>(null);
+    AtomicReference<io.grpc.Metadata> trailers = new AtomicReference<>(null);
     ManagedChannel channel = ManagedChannelBuilder.forTarget("127.0.0.1:" + mockServer.getPort())
       .usePlaintext()
+      .intercept(MetadataUtils.newAttachHeadersInterceptor(metadata))
+      .intercept(MetadataUtils.newCaptureMetadataInterceptor(headers, trailers))
       .build();
     CalculatorGrpc.CalculatorBlockingStub stub = newBlockingStub(channel);
 

examples/gRPC/provider-states/provider-jvm/server/src/main/kotlin/io/pact/example/grpc/provider/Server.kt

@@ -2,14 +2,22 @@ package io.pact.example.grpc.provider
 
 import area_calculator.AreaCalculator
 import area_calculator.CalculatorGrpcKt
+import io.grpc.Metadata
 import io.grpc.ServerBuilder
+import io.grpc.ServerCall
+import io.grpc.ServerCallHandler
+import io.grpc.ServerInterceptor
+import io.grpc.Status
 import mu.KLogging
+import java.util.regex.Pattern
 import kotlin.math.PI
 import kotlin.math.pow
 import kotlin.math.sqrt
 
 class Server {
-    private val server = ServerBuilder.forPort(0).addService(CalculatorService()).build()
+    private val server = ServerBuilder.forPort(0)
+        .intercept(CalculatorInterceptor())
+        .addService(CalculatorService()).build()
 
     fun start() {
         server.start()
@@ -34,6 +42,36 @@ class Server {
     fun serverPort() = server.port
 }
 
+class CalculatorInterceptor : ServerInterceptor {
+    val authKey: Metadata.Key<String> = Metadata.Key.of("Auth", Metadata.ASCII_STRING_MARSHALLER)
+    val authCheckPatten: Pattern = Pattern.compile("[A-Z]{3}\\d{3}")
+
+    override fun <ReqT : Any?, RespT : Any?> interceptCall(
+        call: ServerCall<ReqT, RespT>,
+        headers: Metadata?,
+        next: ServerCallHandler<ReqT, RespT>?
+    ): ServerCall.Listener<ReqT> {
+        val auth = headers?.get(authKey)
+        return if (auth.isNullOrEmpty()) {
+            call.close(Status.UNAUTHENTICATED, Metadata())
+            NoOpListener()
+        } else {
+            if (authCheckPatten.matcher(auth).matches()) {
+                if (next != null) {
+                    next.startCall(call, headers)
+                } else {
+                    NoOpListener()
+                }
+            } else {
+                call.close(Status.UNAUTHENTICATED, Metadata())
+                NoOpListener()
+            }
+        }
+    }
+}
+
+class NoOpListener<ReqT> : ServerCall.Listener<ReqT>()
+
 class CalculatorService : CalculatorGrpcKt.CalculatorCoroutineImplBase() {
     override suspend fun calculateOne(request: AreaCalculator.ShapeMessage): AreaCalculator.AreaResponse {
         val area = when (request.shapeCase) {

examples/gRPC/provider-states/provider-jvm/server/src/test/java/io/pact/example/grpc/provider/PactVerificationTest.java

@@ -53,6 +53,10 @@ void pactVerificationTestTemplate(PactVerificationContext context) {
   @State("a rectangle")
   Map<String, Object> rectangleState() {
     LOGGER.debug("!!! rectangleState state called !!!");
-    return Map.of("rectangleWidth", 5, "rectangleLength", 10);
+    return Map.of(
+      "rectangleWidth", 5,
+      "rectangleLength", 10,
+      "Auth", "CCV001"
+    );
   }
 }