test: rework lib stuff to share common files

test/lib/emitter/plugin/main.cpp

@@ -0,0 +1,28 @@
+#define CR_HOST
+
+#include <gtest/gtest.h>
+#include <cr.h>
+#include "types.h"
+
+TEST(Lib, Emitter) {
+    test_emitter emitter;
+    int value{};
+
+    ASSERT_EQ(value, 0);
+
+    emitter.on<message>([&](message msg, test_emitter &owner) {
+        value = msg.payload;
+        owner.erase<message>();
+    });
+
+    cr_plugin ctx;
+    cr_plugin_load(ctx, PLUGIN);
+
+    ctx.userdata = &emitter;
+    cr_plugin_update(ctx);
+
+    ASSERT_EQ(value, 42);
+
+    emitter = {};
+    cr_plugin_close(ctx);
+}

test/lib/emitter/plugin/plugin.cpp

@@ -0,0 +1,19 @@
+#include <cr.h>
+#include "types.h"
+
+CR_EXPORT int cr_main(cr_plugin *ctx, cr_op operation) {
+    switch(operation) {
+    case CR_STEP:
+        static_cast<test_emitter *>(ctx->userdata)->publish(event{});
+        static_cast<test_emitter *>(ctx->userdata)->publish(message{42});
+        static_cast<test_emitter *>(ctx->userdata)->publish(message{3});
+        break;
+    case CR_CLOSE:
+    case CR_LOAD:
+    case CR_UNLOAD:
+        // nothing to do here, this is only a test.
+        break;
+    }
+
+    return 0;
+}

test/lib/emitter/plugin/types.h

@@ -0,0 +1,15 @@
+#ifndef ENTT_LIB_EMITTER_PLUGIN_TYPES_H
+#define ENTT_LIB_EMITTER_PLUGIN_TYPES_H
+
+#include <entt/signal/emitter.hpp>
+
+struct test_emitter
+    : entt::emitter<test_emitter> {};
+
+struct message {
+    int payload;
+};
+
+struct event {};
+
+#endif