util.events: Add tests

1 files changed, 191 insertions, 0 deletions

diff --git a/spec/util_events_spec.lua b/spec/util_events_spec.lua
new file mode 100644
index 00000000..82b30311
--- /dev/null
+++ b/spec/util_events_spec.lua
@@ -0,0 +1,191 @@
+local events = require "util.events";
+
+describe("util.events", function ()
+	it("should export a new() function", function ()
+		assert.is_function(events.new);
+	end);
+	describe("new()", function ()
+		it("should return return a new events object", function ()
+			local e = events.new();
+			assert.is_function(e.add_handler);
+			assert.is_function(e.remove_handler);
+		end);
+	end);
+
+	local e, h;
+
+
+	describe("API", function ()
+		before_each(function ()
+			e = events.new();
+			h = spy.new(function () end);
+		end);
+
+		it("should call handlers when an event is fired", function ()
+			e.add_handler("myevent", h);
+			e.fire_event("myevent");
+			assert.spy(h).was_called();
+		end);
+
+		it("should not call handlers when a different event is fired", function ()
+			e.add_handler("myevent", h);
+			e.fire_event("notmyevent");
+			assert.spy(h).was_not_called();
+		end);
+
+		it("should pass the data argument to handlers", function ()
+			e.add_handler("myevent", h);
+			e.fire_event("myevent", "mydata");
+			assert.spy(h).was_called_with("mydata");
+		end);
+
+		it("should support non-string events", function ()
+			local myevent = {};
+			e.add_handler(myevent, h);
+			e.fire_event(myevent, "mydata");
+			assert.spy(h).was_called_with("mydata");
+		end);
+
+		it("should call handlers in priority order", function ()
+			local data = {};
+			e.add_handler("myevent", function () table.insert(data, "h1"); end, 5);
+			e.add_handler("myevent", function () table.insert(data, "h2"); end, 3);
+			e.add_handler("myevent", function () table.insert(data, "h3"); end);
+			e.fire_event("myevent", "mydata");
+			assert.same(data, { "h1", "h2", "h3" });
+		end);
+
+		it("should support non-integer priority values", function ()
+			local data = {};
+			e.add_handler("myevent", function () table.insert(data, "h1"); end, 1);
+			e.add_handler("myevent", function () table.insert(data, "h2"); end, 0.5);
+			e.add_handler("myevent", function () table.insert(data, "h3"); end, 0.25);
+			e.fire_event("myevent", "mydata");
+			assert.same(data, { "h1", "h2", "h3" });
+		end);
+
+		it("should support negative priority values", function ()
+			local data = {};
+			e.add_handler("myevent", function () table.insert(data, "h1"); end, 1);
+			e.add_handler("myevent", function () table.insert(data, "h2"); end, 0);
+			e.add_handler("myevent", function () table.insert(data, "h3"); end, -1);
+			e.fire_event("myevent", "mydata");
+			assert.same(data, { "h1", "h2", "h3" });
+		end);
+
+		it("should support removing handlers", function ()
+			e.add_handler("myevent", h);
+			e.fire_event("myevent");
+			e.remove_handler("myevent", h);
+			e.fire_event("myevent");
+			assert.spy(h).was_called(1);
+		end);
+
+		it("should support adding multiple handlers at the same time", function ()
+			local ht = {
+				myevent1 = spy.new(function () end);
+				myevent2 = spy.new(function () end);
+				myevent3 = spy.new(function () end);
+			};
+			e.add_handlers(ht);
+			e.fire_event("myevent1");
+			e.fire_event("myevent2");
+			assert.spy(ht.myevent1).was_called();
+			assert.spy(ht.myevent2).was_called();
+			assert.spy(ht.myevent3).was_not_called();
+		end);
+
+		it("should support removing multiple handlers at the same time", function ()
+			local ht = {
+				myevent1 = spy.new(function () end);
+				myevent2 = spy.new(function () end);
+				myevent3 = spy.new(function () end);
+			};
+			e.add_handlers(ht);
+			e.remove_handlers(ht);
+			e.fire_event("myevent1");
+			e.fire_event("myevent2");
+			assert.spy(ht.myevent1).was_not_called();
+			assert.spy(ht.myevent2).was_not_called();
+			assert.spy(ht.myevent3).was_not_called();
+		end);
+
+		pending("should support adding handlers within an event handler")
+		pending("should support removing handlers within an event handler")
+
+		describe("wrappers", function ()
+			local w
+			before_each(function ()
+				w = spy.new(function (handlers, event_name, event_data)
+					assert.is_function(handlers);
+					assert.equal("myevent", event_name)
+					assert.equal("abc", event_data);
+					return handlers(event_name, event_data);
+				end);
+			end);
+
+			it("should get called", function ()
+				e.add_wrapper("myevent", w);
+				e.add_handler("myevent", h);
+				e.fire_event("myevent", "abc");
+				assert.spy(w).was_called(1);
+				assert.spy(h).was_called(1);
+			end);
+
+			it("should be removable", function ()
+				e.add_wrapper("myevent", w);
+				e.add_handler("myevent", h);
+				e.fire_event("myevent", "abc");
+				e.remove_wrapper("myevent", w);
+				e.fire_event("myevent", "abc");
+				assert.spy(w).was_called(1);
+				assert.spy(h).was_called(2);
+			end);
+
+			it("should allow multiple wrappers", function ()
+				local w2 = spy.new(function (handlers, event_name, event_data)
+					return handlers(event_name, event_data);
+				end);
+				e.add_wrapper("myevent", w);
+				e.add_handler("myevent", h);
+				e.add_wrapper("myevent", w2);
+				e.fire_event("myevent", "abc");
+				e.remove_wrapper("myevent", w);
+				e.fire_event("myevent", "abc");
+				assert.spy(w).was_called(1);
+				assert.spy(w2).was_called(2);
+				assert.spy(h).was_called(2);
+			end);
+		end);
+
+		describe("global wrappers", function ()
+			local w
+			before_each(function ()
+				w = spy.new(function (handlers, event_name, event_data)
+					assert.is_function(handlers);
+					assert.equal("myevent", event_name)
+					assert.equal("abc", event_data);
+					return handlers(event_name, event_data);
+				end);
+			end);
+
+			it("should get called", function ()
+				e.add_wrapper(false, w);
+				e.add_handler("myevent", h);
+				e.fire_event("myevent", "abc");
+				assert.spy(w).was_called(1);
+				assert.spy(h).was_called(1);
+			end);
+
+			it("should be removable", function ()
+				e.add_wrapper(false, w);
+				e.add_handler("myevent", h);
+				e.fire_event("myevent", "abc");
+				e.remove_wrapper(false, w);
+				e.fire_event("myevent", "abc");
+				assert.spy(w).was_called(1);
+				assert.spy(h).was_called(2);
+			end);
+		end);
+	end);
+end);