Adding client-side and server-side interactions. Also adds purpur/paper support

sdk/context_test.go

@@ -0,0 +1,31 @@
+package sdk
+
+import "testing"
+
+func TestSystemCallUsesBuiltInType(t *testing.T) {
+	context := &Context{}
+	runtimeID := 42
+	id := context.SystemCall(SystemCallGetEntity, GetEntityRequest{RuntimeID: &runtimeID})
+
+	if id == "" {
+		t.Fatal("SystemCall returned an empty id")
+	}
+	if len(context.systemCalls) != 1 {
+		t.Fatalf("got %d queued calls, want 1", len(context.systemCalls))
+	}
+	if got := context.systemCalls[0].Name; got != "minecraft:get_entity" {
+		t.Fatalf("queued call name = %q, want %q", got, "minecraft:get_entity")
+	}
+}
+
+func TestCustomSystemCallKeepsExtensionPoint(t *testing.T) {
+	context := &Context{}
+	context.CustomSystemCall("example:claim.owner", nil)
+
+	if len(context.systemCalls) != 1 {
+		t.Fatalf("got %d queued calls, want 1", len(context.systemCalls))
+	}
+	if got := context.systemCalls[0].Name; got != "example:claim.owner" {
+		t.Fatalf("queued call name = %q, want %q", got, "example:claim.owner")
+	}
+}