Allow rejection with error objects

lib/init.lua

@@ -131,11 +131,20 @@ end
 
 
 local function makeErrorHandler(traceback)
+	assert(traceback ~= nil)
+
 	return function(err)
+		-- If the error object is already a table, forward it directly.
+		-- Should we extend the error here and add our own trace?
+
+		if type(err) == "table" then
+			return err
+		end
+
 		return Error.new({
 			error = err,
 			kind = Error.Kind.ExecutionError,
-			trace = debug.traceback(err, 2),
+			trace = debug.traceback(tostring(err), 2),
 			context = "Promise created at:\n\n" .. traceback
 		})
 	end

lib/init.spec.lua

@@ -925,6 +925,16 @@ return function()
 			expect(errorText:find("errortext")).to.be.ok()
 		end)
 
+		it("should reject with error objects", function()
+			local object = {}
+			local success, value = Promise.try(function()
+				error(object)
+			end):_unwrap()
+
+			expect(success).to.equal(false)
+			expect(value).to.equal(object)
+		end)
+
 		it("should catch asynchronous errors", function()
 			local bindable = Instance.new("BindableEvent")
 			local promise = Promise.try(function()