Angular 2 CLI + Webpack ng build - 生成大警告

Question

我的應用程序構建正常。但是當我在我的控制檯中輸入

ng build --prod 建立生產，我得到以下巨頭警告，並怪dist輸出：

WARNING in main.ff67c2edc2d42d6adb60.bundle.js from UglifyJs 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:235,5] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:5310,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:5310,4] 
Side effects in initialization of unused variable TypeModifier [main.ff67c2edc2d42d6adb60.bundle.js:5476,4] 
Side effects in initialization of unused variable BuiltinMethod [main.ff67c2edc2d42d6adb60.bundle.js:5732,4] 
Side effects in initialization of unused variable StmtModifier [main.ff67c2edc2d42d6adb60.bundle.js:5966,4] 
Side effects in initialization of unused variable freeExports [main.ff67c2edc2d42d6adb60.bundle.js:8176,4] 
Side effects in initialization of unused variable freeModule [main.ff67c2edc2d42d6adb60.bundle.js:8177,4] 
Side effects in initialization of unused variable ProviderAstType [main.ff67c2edc2d42d6adb60.bundle.js:9022,4] 
Side effects in initialization of unused variable PropertyBindingType [main.ff67c2edc2d42d6adb60.bundle.js:9063,4] 
Side effects in initialization of unused variable RequestMethod [main.ff67c2edc2d42d6adb60.bundle.js:9394,4] 
Side effects in initialization of unused variable ReadyState [main.ff67c2edc2d42d6adb60.bundle.js:9409,4] 
Side effects in initialization of unused variable ResponseType [main.ff67c2edc2d42d6adb60.bundle.js:9422,4] 
Side effects in initialization of unused variable ContentType [main.ff67c2edc2d42d6adb60.bundle.js:9436,4] 
Side effects in initialization of unused variable ResponseContentType [main.ff67c2edc2d42d6adb60.bundle.js:9447,4] 
Side effects in initialization of unused variable TagContentType [main.ff67c2edc2d42d6adb60.bundle.js:11792,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:12589,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:12589,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:15093,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:15093,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:15143,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:15143,4] 
Side effects in initialization of unused variable ViewType [main.ff67c2edc2d42d6adb60.bundle.js:19907,4] 
Side effects in initialization of unused variable HTMLCollection [main.ff67c2edc2d42d6adb60.bundle.js:21081,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:23278,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:23278,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:23323,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:23323,4] 
Side effects in initialization of unused variable HTMLCollection [main.ff67c2edc2d42d6adb60.bundle.js:25631,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:27538,8] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:27538,8] 
Dropping unused variable SAFE_SRCSET_PATTERN [main.ff67c2edc2d42d6adb60.bundle.js:33759,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:34293,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:34293,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:34392,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:34392,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:34498,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:34498,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:34603,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:34603,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35538,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35616,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35679,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35786,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35851,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:35990,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36101,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36237,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36331,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36454,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36577,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36690,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36836,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:36921,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:36945,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:36954,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:36963,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:36972,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:36981,16] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37097,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37164,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37248,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37315,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37397,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37477,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37580,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37681,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37752,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37819,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37890,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:37960,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38033,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38107,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38192,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38278,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38361,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38431,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38541,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38652,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38716,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38780,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38848,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38916,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:38993,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39073,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39156,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39257,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39385,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39534,4] 
Dropping unused variable suffix [main.ff67c2edc2d42d6adb60.bundle.js:39543,12] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39647,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39747,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39833,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:39965,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40038,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40119,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40205,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40298,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40389,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40455,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40523,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40615,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40755,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40829,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:40951,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41051,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41166,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41260,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41346,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41509,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41595,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41681,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41779,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41845,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:41972,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42049,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42113,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42241,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42350,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42415,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42485,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42565,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42750,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42815,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:42891,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:42915,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:42924,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:42933,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:42942,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:42951,16] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43044,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43212,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43284,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43398,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43512,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43605,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43678,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43741,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43874,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:43967,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44038,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44104,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44229,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44322,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44417,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44479,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44542,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44691,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44753,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44836,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:44909,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:45040,4] 
Side effects in initialization of unused variable matches [main.ff67c2edc2d42d6adb60.bundle.js:47583,12] 
Dropping unused variable __unused [main.ff67c2edc2d42d6adb60.bundle.js:47891,4] 
Non-strict equality against boolean: != true [main.ff67c2edc2d42d6adb60.bundle.js:49247,15] 
Side effects in initialization of unused variable transitiveModuleMeta [main.ff67c2edc2d42d6adb60.bundle.js:50293,16] 
Dropping unused variable EVENT [main.ff67c2edc2d42d6adb60.bundle.js:50654,4] 
Side effects in initialization of unused variable SecurityContext [main.ff67c2edc2d42d6adb60.bundle.js:58783,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:61560,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:61560,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:61730,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:61730,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:61842,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:61842,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62014,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62014,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62075,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62075,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62180,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62180,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62667,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62667,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62726,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62726,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62933,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62933,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:62989,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:62989,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63114,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63114,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63236,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63236,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63351,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63351,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63391,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63391,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63515,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63515,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63805,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63805,4] 
Non-strict equality against boolean: == true [main.ff67c2edc2d42d6adb60.bundle.js:63892,16] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:63936,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:63936,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64000,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64000,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64149,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64149,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64322,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64322,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64362,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64362,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64421,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64421,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64513,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64513,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64558,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64558,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:64839,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:64839,4] 
Non-strict equality against boolean: != false [main.ff67c2edc2d42d6adb60.bundle.js:67116,47] 
Dropping unused function _fetchSylesFromState [main.ff67c2edc2d42d6adb60.bundle.js:71181,9] 
Side effects in initialization of unused variable strCases [main.ff67c2edc2d42d6adb60.bundle.js:72884,12] 
Dropping unused variable renderMethod [main.ff67c2edc2d42d6adb60.bundle.js:75587,12] 
Dropping unused variable __unused [main.ff67c2edc2d42d6adb60.bundle.js:76550,4] 
Dropping unused function normalizeArray [main.ff67c2edc2d42d6adb60.bundle.js:79198,9] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:81819,12] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:81819,12] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:81843,8] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:81843,8] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:82393,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:82393,4] 
Side effects in initialization of unused variable pathLocationStrategy [main.ff67c2edc2d42d6adb60.bundle.js:82878,4] 
Side effects in initialization of unused variable hashLocationStrategy [main.ff67c2edc2d42d6adb60.bundle.js:82882,4] 
Dropping side-effect-free statement [main.ff67c2edc2d42d6adb60.bundle.js:83003,0] 
Side effects in initialization of unused variable __WEBPACK_IMPORTED_MODULE_5__src_dnd_component__ [main.ff67c2edc2d42d6adb60.bundle.js:82991,25] 
Dropping unused variable appRoutingProviders [main.ff67c2edc2d42d6adb60.bundle.js:83328,4] 
Side effects in initialization of unused variable __WEBPACK_IMPORTED_MODULE_0__environments_environment__ [main.ff67c2edc2d42d6adb60.bundle.js:83371,25] 
Side effects in initialization of unused variable __WEBPACK_IMPORTED_MODULE_1__app_component__ [main.ff67c2edc2d42d6adb60.bundle.js:83372,25] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:93857,4] 
Declarations in unreachable code! [main.ff67c2edc2d42d6adb60.bundle.js:93857,4] 
Condition always true [main.ff67c2edc2d42d6adb60.bundle.js:96729,4] 
Dropping unreachable code [main.ff67c2edc2d42d6adb60.bundle.js:96733,7] 

WARNING in polyfills.c27b87b9e504b84ce8dc.bundle.js from UglifyJs 
Condition left of || always false [polyfills.c27b87b9e504b84ce8dc.bundle.js:3722,63] 
Condition left of || always false [polyfills.c27b87b9e504b84ce8dc.bundle.js:3723,62] 
Dropping side-effect-free statement [polyfills.c27b87b9e504b84ce8dc.bundle.js:3751,21] 
Side effects in initialization of unused variable Zone [polyfills.c27b87b9e504b84ce8dc.bundle.js:3274,5] 

有什麼不對？

Answer 1

該警告告訴你到底發生了什麼錯誤，你的代碼中有一個if語句會總是評估爲true，可能導致其他代碼永遠不會執行。

這可能是預期的和期望的行爲，但那麼你的代碼應該寫成不同的。重構if語句並且警告消失。

此警告只是一個警告，您生成的dist文件夾生成正確，所以沒有任何突破。

Answer 2

就像stijn26說：我們有意在angular-cli中配置webpack來發出這些警告。它們代表正在代碼中發生的優化和死代碼清除。

我們沒有辦法壓制警告，但我個人認爲，我喜歡看到這個結果，以確切知道我的代碼在未來可以優化的位置。