Is dead code elimination really working?

Bắt đầu với cấu hình build trong profile.cljs và namespace cùng điểm vào dev-setup trong core.cljs, sử dụng template reagent-figwheel và các thiết lập advanced-optimization được liệt kê. Tái hiện năm build và so sánh kích thước đầu ra của chúng; hoàn thành có nghĩa là giải thích liệu dependency devtools không được sử dụng có bị loại bỏ hay không, đồng thời ghi lại hoặc sửa kết quả quan sát được.

I can't seem to bring the code size down with a barely empty project through dead-code elimination alone, even when following the installation instructions to the letter.

The template used was reagent-figwheel with only devtools and reagent as dependencies. I've fiddled with the goog.DEBUG flag, and then removed devtools from the :require and :dependencies vectors.

The first two rows followed the instructions from the release notes. There's a single mention of (devtools/install!) within a (when ^boolean js/goog.DEBUG ...) block. The other three had this line removed manually.

Google Closure's shaved 400kb of the build, but that's still a 800kb increase for a :require without a single mention of devtools! Is this the best I can expect from dead code elimination?

Here's the code used for the builds (e.g. lein new reagent-figwheel +devtools):

;##################
;### profile.cljs

(defproject devtools-dce "0.1.0-SNAPSHOT"
 :dependencies [[org.clojure/clojure "1.8.0"]
                [org.clojure/clojurescript "1.9.229"]
                [reagent "0.6.0"]
                [binaryage/devtools "0.8.2"]]

  [...]

 :cljsbuild
 {:builds
  [{:id           "min"
    :source-paths ["src/cljs"]
    :compiler     {:main            devtools-dce.core
                   :optimizations   :advanced
                   :output-to       "resources/public/js/compiled/app.js"
                   :output-dir      "resources/public/js/compiled/min"
                   :closure-defines {goog.DEBUG false}
                   :pseudo-names    true   ;; added to exacerbate size difference
                   :pretty-print    false}}

   ]})

;##############
;## core.cljs

(ns devtools-dce.core
 (:require
  [reagent.core :as reagent]
  [devtools.core :as devtools]
  ))

[...]

(defn dev-setup []        ;; inlining into `main` made no difference
 (when ^boolean js/goog.DEBUG
   (enable-console-print!)
   (println "dev mode")
   (devtools/install!)
   ))

(defn ^:export main []
 (dev-setup)
 (reload))