refactor(commands) swap argument order to match Http(w, r) idiom

commands/command.go

@@ -12,7 +12,7 @@ var log = u.Logger("command")
 
 // Function is the type of function that Commands use.
 // It reads from the Request, and writes results to the Response.
-type Function func(Request, Response)
+type Function func(Response, Request)
 
 // Formatter is a function that takes in a Response, and returns a human-readable string
 // (or an error on failure)
@@ -63,7 +63,7 @@ func (c *Command) Call(req Request) Response {
 		return res
 	}
 
-	cmd.Run(req, res)
+	cmd.Run(res, req)
 
 	return res
 }

commands/command_test.go

@@ -8,7 +8,7 @@ func TestOptionValidation(t *testing.T) {
 			Option{[]string{"b", "beep"}, Int},
 			Option{[]string{"B", "boop"}, String},
 		},
-		Run: func(req Request, res Response) {},
+		Run: func(res Response, req Request) {},
 	}
 
 	req := NewEmptyRequest()
@@ -79,7 +79,7 @@ func TestOptionValidation(t *testing.T) {
 }
 
 func TestRegistration(t *testing.T) {
-	noop := func(req Request, res Response) {}
+	noop := func(res Response, req Request) {}
 
 	cmdA := &Command{
 		Options: []Option{