Add new integration-tests for server

This `integration-tests` directory makes it possible to write
Rust code that you can run directly against the generated servers
from the protocol test models. This makes it easier to test things
like event streams behavior and other specifics that are hard to
test with protocol tests alone.

Author: rcoh

codegen-server-test/build.gradle.kts

@@ -110,6 +110,12 @@ tasks["assemble"].finalizedBy("generateCargoWorkspace", "generateCargoConfigToml
 project.registerModifyMtimeTask()
 project.registerCargoCommandsTasks(layout.buildDirectory.dir(workingDirUnderBuildDir).get().asFile)
 
-tasks["test"].finalizedBy(cargoCommands(properties).map { it.toString })
+tasks.register<Exec>("cargoTestIntegration") {
+    dependsOn("assemble")
+    workingDir(projectDir.resolve("integration-tests"))
+    commandLine("cargo", "test")
+}
+
+tasks["test"].finalizedBy(cargoCommands(properties).map { it.toString }, "cargoTestIntegration")
 
 tasks["clean"].doFirst { delete("smithy-build.json") }

codegen-server-test/integration-tests/.gitignore

@@ -0,0 +1 @@
+Cargo.lock