engine: Add optional parameter to trigger configuration

Perhaps a better name would be `ignore_missing`, since this
will essentially ignore the trigger if the event or action
cannot be created.

Author: cassava

engine/src/coordinator.cpp

@@ -261,8 +261,20 @@ ActionPtr Coordinator::make_action(const Conf& c) const { return make_some<Actio
 EventPtr Coordinator::make_event(const Conf& c) const { return make_some<Event>(c, events_); }
 
 TriggerPtr Coordinator::make_trigger(Source s, const Conf& c) const {
-  auto ep = make_event(c.at("event"));
-  auto ap = make_action(c.at("action"));
+  EventPtr ep;
+  ActionPtr ap;
+  bool opt = c.get_or("optional", false);
+  try {
+    ep = make_event(c.at("event"));
+    ap = make_action(c.at("action"));
+  } catch (TriggerError& e) {
+    if (opt) {
+      logger()->warn("Ignoring optional trigger ({}): {}", e.what(), c->dump());
+      return nullptr;
+    } else {
+      throw;
+    }
+  }
   auto label = c.get_or<std::string>("label", "");
   auto t = std::make_unique<Trigger>(label, s, std::move(ep), std::move(ap));
   t->set_sticky(c.get_or("sticky", false));
@@ -271,6 +283,10 @@ TriggerPtr Coordinator::make_trigger(Source s, const Conf& c) const {
 }
 
 void Coordinator::queue_trigger(TriggerPtr&& t) {
+  if (t == nullptr) {
+    // This only really happens if a trigger is an optional trigger.
+    return;
+  }
   std::unique_lock<std::mutex> guard(input_mutex_);
   input_queue_.emplace_back(std::move(t));
 }

engine/src/stack.hpp

@@ -786,6 +786,7 @@ struct TriggerConf : public PersistentConfable {
   Conf action{};
   Conf event{};
   bool sticky{false};
+  bool optional{false};
 
  public:  // Confable Overrides
   CONFABLE_SCHEMA(TriggerConf) {
@@ -803,6 +804,7 @@ struct TriggerConf : public PersistentConfable {
         {"event", make_schema(&event, EANDA_SCHEMA, "event").require()},
         {"action", make_schema(&action, EANDA_SCHEMA, "action").require()},
         {"sticky", make_schema(&sticky, "whether trigger should be sticky")},
+        {"optional", make_schema(&optional, "whether errors creating event or action should be ignored")},
         {"at", Ignore("time at which trigger was executed", JsonType::string)},
         {"since", Ignore("time since which trigger was in queue", JsonType::string)},
     };

engine/tests/test_engine.bats

@@ -51,6 +51,21 @@ check_engine_with_server() {
     test $status -eq $CLOE_EXIT_UNKNOWN
 }
 
+@test "$(testname "Expect run failure" "test_engine_invalid_trigger.json" "0cf8c9e0-5538-4969-a00e-4891d7d8e647")" {
+    # Currently, cloe-engine cannot tell before starting a simulation
+    # whether the triggers exist or not.
+    cloe-engine check test_engine_invalid_trigger.json
+
+    run cloe-engine run test_engine_invalid_trigger.json
+    assert_check_failure $status $output
+    test $status -eq $CLOE_EXIT_ABORTED
+}
+
+@test "$(testname 'Expect run success' 'test_engine_optional_trigger.json' 'c630a68c-8b1e-436a-8acf-b282b1e1830c')" {
+    cloe-engine check test_engine_optional_trigger.json
+    cloe-engine run test_engine_optional_trigger.json
+}
+
 @test "$(testname "Expect check success" "test_engine_curl_succeed.json" "5eff0c85-77f1-4792-9987-e46a36617d99")" {
     cloe-engine check test_engine_curl_succeed.json
 }

engine/tests/test_engine_invalid_trigger.json

@@ -0,0 +1,10 @@
+{
+  "version": "4",
+  "include": [
+    "config_nop_smoketest.json"
+  ],
+  "triggers": [
+    { "event": "nonexistent", "action": "log=info: Hello nonexistent event." },
+    { "event": "start", "action": "nonexistent" }
+  ]
+}

engine/tests/test_engine_json_schema.json

@@ -1155,6 +1155,10 @@
               }
             ]
           },
+          "optional": {
+            "description": "whether errors creating event or action should be ignored",
+            "type": "boolean"
+          },
           "since": {
             "description": "time since which trigger was in queue"
           },

engine/tests/test_engine_nop_smoketest_dump.json

@@ -93,24 +93,28 @@
         "name": "bundle"
       },
       "event": "start",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "basic/hmi=enable",
       "event": "next=1",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "basic/hmi=resume",
       "event": "time=5",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "basic/hmi=!resume",
       "event": "time=5.5",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
@@ -130,37 +134,43 @@
       },
       "event": "time=6",
       "label": "Push and release basic/hmi=plus",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "fail",
       "event": "virtue/failure",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "fail",
       "event": "default_speed/kmph=>0.0",
       "label": "Vehicle default should never move with the nop binding.",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "log=info: Running nop/basic smoketest.",
       "event": "start",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "realtime_factor=-1",
       "event": "start",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     },
     {
       "action": "succeed",
       "event": "time=60",
+      "optional": false,
       "source": "filesystem",
       "sticky": false
     }

engine/tests/test_engine_nop_smoketest_dump_with_vtd.json

@@ -0,0 +1,10 @@
+{
+  "version": "4",
+  "include": [
+    "config_nop_smoketest.json"
+  ],
+  "triggers": [
+    { "event": "nonexistent", "action": "log=info: Hello nonexistent event.", "optional": true },
+    { "event": "start", "action": "nonexistent", "optional": true }
+  ]
+}