无法分配给引用或变量中的 Angular 产品构建错误

我无法构建我的角度应用程序的产品版本。

IDE 控制台中只有此消息：

错误无法分配给引用或变量！

所以我只有添加这些选项才能构建：

--aot=false --buildOptimizer=false

但是，即使使用这些选项，应用程序在部署后也会失败，并在浏览器控制台中显示以下消息：

错误类型错误：无法读取未定义的属性“init”

这可以是fixed https://github.com/angular/flex-layout/issues/950添加一个选项：

--optimization=false 

当我尝试构建时

npm run ng build -- --prod

我有一个包含一些信息的日志文件：

0 info it worked if it ends with ok
1 verbose cli [ 'C:\\Backend\\nodejs\\node.exe',
1 verbose cli   'C:\\Users\\USER_NAME\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js',
1 verbose cli   'run',
1 verbose cli   'ng',
1 verbose cli   'build',
1 verbose cli   '--',
1 verbose cli   '--prod' ]
2 info using [email protected] /cdn-cgi/l/email-protection
3 info using [email protected] /cdn-cgi/l/email-protection
4 verbose run-script [ 'preng', 'ng', 'postng' ]
5 info lifecycle [email protected] /cdn-cgi/l/email-protection~preng: [email protected] /cdn-cgi/l/email-protection
6 info lifecycle [email protected] /cdn-cgi/l/email-protection~ng: [email protected] /cdn-cgi/l/email-protection
7 verbose lifecycle [email protected] /cdn-cgi/l/email-protection~ng: unsafe-perm in lifecycle true
8 verbose lifecycle [email protected] /cdn-cgi/l/email-protection~ng: PATH: C:\Users\USER_NAME\AppData\Roaming\npm\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin;C:\DEV\WebStormProjects\dont-play-with-gp-web\node_modules\.bin;C:\DEV\WebStormProjects\dont-play-with-gp-web\node_modules\.bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Backend\IntelliJ IDEA 2018.3.5\jre64;C:\Backend\PostgreSQL\10\bin;C:\Backend\nodejs;C:\Backend\WinSCP\;C:\Android\sdk\platform-tools;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Users\USER_NAME\AppData\Local\Microsoft\WindowsApps;
9 verbose lifecycle [email protected] /cdn-cgi/l/email-protection~ng: CWD: C:\DEV\WebStormProjects\dont-play-with-gp-web
10 silly lifecycle [email protected] /cdn-cgi/l/email-protection~ng: Args: [ '/d /s /c', 'ng "build" "--prod"' ]
11 silly lifecycle [email protected] /cdn-cgi/l/email-protection~ng: Returned: code: 1  signal: null
12 info lifecycle dont-play-[email protected] /cdn-cgi/l/email-protection~ng: Failed to exec ng script
13 verbose stack Error: [email protected] /cdn-cgi/l/email-protection ng: `ng "build" "--prod"`
13 verbose stack Exit status 1
13 verbose stack     at EventEmitter.<anonymous> (C:\Users\USER_NAME\AppData\Roaming\npm\node_modules\npm\node_modules\npm-lifecycle\index.js:326:16)
13 verbose stack     at EventEmitter.emit (events.js:189:13)
13 verbose stack     at ChildProcess.<anonymous> (C:\Users\USER_NAME\AppData\Roaming\npm\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:189:13)
13 verbose stack     at maybeClose (internal/child_process.js:970:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
14 verbose pkgid [email protected] /cdn-cgi/l/email-protection
15 verbose cwd C:\DEV\WebStormProjects\dont-play-with-gp-web
16 verbose Windows_NT 10.0.17134
17 verbose argv "C:\\Backend\\nodejs\\node.exe" "C:\\Users\\USER_NAME\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "run" "ng" "build" "--" "--prod"
18 verbose node v10.15.3
19 verbose npm  v6.10.2
20 error code ELIFECYCLE
21 error errno 1
22 error [email protected] /cdn-cgi/l/email-protection ng: `ng "build" "--prod"`
22 error Exit status 1
23 error Failed at the [email protected] /cdn-cgi/l/email-protection ng script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]

我尝试更新所有内容，但没有帮助。

这是结果ng version:

Angular CLI: 8.3.4
Node: 10.15.3
OS: win32 x64
Angular: 8.2.6
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.803.4
@angular-devkit/build-angular     0.803.4
@angular-devkit/build-optimizer   0.803.4
@angular-devkit/build-webpack     0.803.4
@angular-devkit/core              8.3.4
@angular-devkit/schematics        8.3.4
@angular/cdk                      8.2.0
@angular/cli                      8.3.4
@angular/flex-layout              8.0.0-beta.27
@angular/material                 8.2.0
@ngtools/webpack                  8.3.4
@schematics/angular               8.3.4
@schematics/update                0.803.4
rxjs                              6.5.3
typescript                        3.5.3
webpack                           4.39.2

And my package.json:

{
  "name": "dont-play-with-gp-web",
  "version": "0.0.2",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^8.2.6",
    "@angular/cdk": "^8.2.0",
    "@angular/common": "~8.2.6",
    "@angular/compiler": "~8.2.6",
    "@angular/core": "~8.2.6",
    "@angular/flex-layout": "8.0.0-beta.27",
    "@angular/forms": "~8.2.6",
    "@angular/material": "^8.2.0",
    "@angular/platform-browser": "~8.2.6",
    "@angular/platform-browser-dynamic": "~8.2.6",
    "@angular/router": "~8.2.6",
    "angular-markdown-editor": "^2.0.2",
    "hammerjs": "^2.0.8",
    "jquery": "^3.4.1",
    "ngx-infinite-scroll": "^8.0.0",
    "ngx-markdown": "^8.1.0",
    "ngx-material-file-input": "^2.0.0",
    "rxjs": "~6.5.3",
    "tslib": "^1.9.0",
    "zone.js": "^0.9.1"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.803.4",
    "@angular/cli": "~8.3.4",
    "@angular/compiler-cli": "~8.2.6",
    "@angular/language-service": "~8.2.6",
    "@types/jasmine": "~3.4.0",
    "@types/jasminewd2": "~2.0.3",
    "@types/jquery": "^3.3.31",
    "@types/node": "~12.7.5",
    "codelyzer": "^5.0.0",
    "jasmine-core": "~3.4.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~2.1.0",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.0",
    "protractor": "~5.4.0",
    "ts-node": "~8.4.1",
    "tslint": "~5.20.0",
    "typescript": "^3.5.3"
  }
}

那么，在这种情况下我能做什么呢？如何查找错误原因以及如何修复？

如果它可以帮助 - 这是我的源代码：

https://bitbucket.org/mohaxspb/gp-web/commits/tag/ATTEMPT_TO_FIX_PROD_BUILD_WITH_DEPS_UPDATE https://bitbucket.org/mohaxspb/gp-web/commits/tag/ATTEMPT_TO_FIX_PROD_BUILD_WITH_DEPS_UPDATE

同样的问题ru.stackoverflow: https://ru.stackoverflow.com/questions/1025395 https://ru.stackoverflow.com/questions/1025395

SOVLED:

最后我有错误原因（所以用户https://stackoverflow.com/users/10123947/shadow https://stackoverflow.com/users/10123947/shadow找到了）：有人尝试更改模板中变量的值，在自制指令的帮助下在模板中定义。

这里的问题在于糟糕的错误消息。提到的用户仅通过调试编译器收到详细信息（据我所知）。有一些细节（俄语）：https://ru.stackoverflow.com/a/1025417/17609 https://ru.stackoverflow.com/a/1025417/17609

UPDATE:

我将问题和 PR 添加到 Angular 存储库来修复它。

1. 错误消息中没有详细信息：issue https://github.com/angular/angular/issues/32759, PR https://github.com/angular/angular/pull/32760
2. 为模板变量赋值会导致产品构建崩溃：issue https://github.com/angular/angular/issues/32761, PR https://github.com/angular/angular/pull/32762

碰巧 AST 解析器的大多数异常都是令人头疼的。只是因为它们不携带任何有用的东西，除了一条消息：

错误无法分配给引用或变量！

哦真的吗？

例如，链接器 (ViewBuilder) 总是写在无法构建模板表达式的地方。

谷歌搜索可能是解决方案之一。但整个圈子将被封闭，因为大多数答案都会提供检查ngModel模板中的指令用法。

第二个选项有点硬编码。值得深入了解编译器本身并进行调试。角度用途node_modules/@angular/compiler/bundles/compiler.umd.js编译期间。

让我们打开这个文件并尝试搜索文本Cannot assign to a reference or variable!。我们会找到_AstToIrVisitor类和visitPropertyWrite方法。有这样一行代码

// Otherwise it's an error.
throw new Error('Cannot assign to a reference or variable!');

抛出异常时根本没有任何信息????

让我们添加console.log(ast)在异常之前，其中ast是的参数visitPropertyWrite功能。解析器将记录一个实例PropertyWrite类到控制台：

PropertyWrite {
  span: ParseSpan { start: 0, end: 73 },
  receiver: ImplicitReceiver { span: ParseSpan { start: 0, end: 0 } },
  name: 'translation',
  value: MethodCall {
    span: ParseSpan { start: 14, end: 73 },
    receiver: ImplicitReceiver { span: [ParseSpan] },
    name: 'getTranslationForLanguageFromArticle',
    args: [ [PropertyRead], [PropertyRead] ]
  }
}

我们得出的结论是，我们必须了解两者之间的关系translation财产和getTranslationForLanguageFromArticle方法调用。当我尝试从 Bitbucket 克隆您的示例时，我查找了“getTranslationForLanguageFromArticle”用法，并在feed.component.html:

(change)="translation = getTranslationForLanguageFromArticle($event.value, article)"

这是解析器无法理解的translation不是类属性。这是一个本地人ng-template隐式访问的变量*ngVar指示。

我会创建一些类似的方法changeTranslation在组件内部并进行操作article.translations[indexOfCorrectArticleTranslation(article)] there.

至少你知道该走哪条路:)