add removeAllListeners API (#16)

* add removeAllListeners and eventNames API
TakeScoop · Sep 10, 2018 · 3d1c42a · 3d1c42a
1 parent 68ef2cb
commit 3d1c42a
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Showing 3 changed files with 88 additions and 0 deletions.
diff --git a/eventemitter_impl.hpp b/eventemitter_impl.hpp
@@ -67,6 +67,35 @@ class EventEmitter {
         it->second->emplace_back(cb);
     }
 
+    /// Remove all listeners for a given event
+    ///
+    /// @param[in] ev - event name
+    virtual void removeAllListenersForEvent(const std::string& ev) {
+        std::unique_lock<uv_rwlock> master_lock{receivers_lock_};
+        auto it = receivers_.find(ev);
+
+        if (it != receivers_.end()) {
+            receivers_.erase(it);
+        }
+    }
+
+    /// Remove all listeners for all events
+    virtual void removeAllListeners() {
+        std::unique_lock<uv_rwlock> master_lock{receivers_lock_};
+        receivers_.clear();
+    }
+
+    // Return a list of all eventNames
+    virtual std::vector<std::string> eventNames() {
+        std::unique_lock<uv_rwlock> master_lock{receivers_lock_};
+        std::vector<std::string> keys;
+
+        for (auto it : receivers_) {
+            keys.emplace_back(it.first);
+        }
+        return keys;
+    }
+
     /// Emit a value to any registered callbacks for the event
     ///
     /// @param[in] ev - event name

diff --git a/test/cpp/eventemitter.cpp b/test/cpp/eventemitter.cpp
@@ -72,6 +72,8 @@ class EmittingThing : public Nan::ObjectWrap {
         Nan::SetPrototypeMethod(constructor, "on", On);
         Nan::SetPrototypeMethod(constructor, "run", Run);
         Nan::SetPrototypeMethod(constructor, "runReentrant", RunReentrant);
+        Nan::SetPrototypeMethod(constructor, "removeAllListeners", RemoveAllListeners);
+        Nan::SetPrototypeMethod(constructor, "eventNames", EventNames);
 
         Nan::Set(target, clsName, Nan::GetFunction(constructor).ToLocalChecked());
     };
@@ -125,6 +127,42 @@ class EmittingThing : public Nan::ObjectWrap {
         Nan::AsyncQueueWorker(worker);
     }
 
+    static NAN_METHOD(RemoveAllListeners) {
+        if (info.Length() > 1) {
+            info.GetIsolate()->ThrowException(Nan::TypeError("Wrong number of arguments"));
+            return;
+        }
+        auto thing = Nan::ObjectWrap::Unwrap<EmittingThing>(info.Holder());
+
+        if (info.Length() == 1) {
+            if (!info[0]->IsString()) {
+                info.GetIsolate()->ThrowException(Nan::TypeError("First argument must be string name of an event"));
+                return;
+            }
+            auto ev = std::string(*v8::String::Utf8Value(info[0]->ToString()));
+            thing->emitter_->removeAllListenersForEvent(ev);
+        } else {
+            thing->emitter_->removeAllListeners();
+        }
+    }
+
+    static NAN_METHOD(EventNames) {
+        if (info.Length() > 0) {
+            info.GetIsolate()->ThrowException(Nan::TypeError("Wrong number of arguments"));
+            return;
+        }
+        auto thing = Nan::ObjectWrap::Unwrap<EmittingThing>(info.Holder());
+        v8::Local<v8::Array> v = v8::Array::New(info.GetIsolate());
+
+        size_t i = 0; 
+        for (auto s : thing->emitter_->eventNames()) {
+            v->Set(i++, v8::String::NewFromUtf8(info.GetIsolate(), s.c_str()));
+        }
+
+        info.GetReturnValue().Set(v);
+    }
+
+
     static NAN_METHOD(RunReentrant) {
         Nan::Callback* fn(nullptr);
         if (info.Length() < 1 || info.Length() > 2) {

diff --git a/test/js/eventemitter.js b/test/js/eventemitter.js
@@ -21,6 +21,27 @@ describe('Verify EventEmitter', function() {
 
             thing.run(n)
         })
+
+        it('should remove listeners for a specific test event', function(done) {
+            let thing = new bindings.EmitterThing()
+            thing.on('test1', function(ev) { })
+            thing.on('test2', function(ev) { })
+
+            expect(thing.eventNames()).to.be.equal(['test2', 'test1'])
+            thing.removeAllListeners('test1')
+            expect(thing.eventNames()).to.be.equal(['test2'])
+            done()
+        })
+
+        it('should remove all listeners for all events', function(done) {
+            let thing = new bindings.EmitterThing()
+            thing.on('test1', function(ev) { })
+            thing.on('test2', function(ev) { })
+
+            thing.removeAllListeners()
+            expect(thing.eventNames()).to.be.equal([])
+            done()
+        })
     })
 
     describe('Verify EventEmitter Multi', function() {