angular-cli: ng build --prod results in that the running app report "TypeError: Assignment to constant variable" with target:es2015

Versions

Angular CLI: 1.6.7
Node: 8.9.4
OS: win32 x64
Angular: 5.2.2
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

@angular/cli: 1.6.7
@angular-devkit/build-optimizer: 0.0.42
@angular-devkit/core: 0.0.29
@angular-devkit/schematics: 0.0.52
@ngtools/json-schema: 1.1.0
@ngtools/webpack: 1.9.7
@schematics/angular: 0.1.17
typescript: 2.6.2
webpack: 3.10.0

The tsconfig.json defined target:es2015

package.json:

  "dependencies": {
    "@angular/animations": "^5.2.2",
    "@angular/common": "^5.2.2",
    "@angular/compiler": "^5.2.2",
    "@angular/core": "^5.2.2",
    "@angular/forms": "^5.2.2",
    "@angular/platform-browser": "^5.2.2",
    "@angular/platform-browser-dynamic": "^5.2.2",
    "@angular/router": "^5.2.2",
    "concurrently": "^3.5.1",
    "core-js": "^2.5.3",
    "rxjs": "^5.5.6",
    "zone.js": "^0.8.19"
  },
  "devDependencies": {
    "@angular/cli": "1.6.7",
    "@angular/compiler-cli": "^5.2.2",
    "@angular/language-service": "^5.2.2",
    "@types/jasmine": "~2.8.3",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "^6.0.85",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.8.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~2.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~4.1.0",
    "tslint": "~5.9.1",
    "uglifyjs-webpack-plugin": "^1.1.8",
    "typescript": "^2.6.2"
  }

Repro steps

• Step 1

Find the simple heros demo app at https://github.com/zijianhuang/webapiclientgen, and locate DemoNGCli

or the demo app downloadable in https://angular.io/tutorial/toh-pt6

• Step 2

Go to respective source folder and run ng build --prod

• Step 3

Run the app with IIS, or you may try Apache or other Web server. And use Chrom or alike browse the app.

Observed behavior

The app will misbehave, with the following console traces when making the first HttpClient call. ERROR TypeError: Assignment to constant variable. at r (main.14d23ee13c3a14c67d46.bundle.js:1) at XMLHttpRequest.a (main.14d23ee13c3a14c67d46.bundle.js:1) at e.invokeTask (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1) at Object.onInvokeTask (main.14d23ee13c3a14c67d46.bundle.js:1) at e.invokeTask (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1) at t.runTask (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1) at t.invokeTask [as invoke] (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1) at _ (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1) at XMLHttpRequest.k (polyfills.8e8e9e6cb9f95b7ba9ab.bundle.js:1)

The HttpClient call is actually successful with status 200 returned.

Desired behavior

Heros display.

Mention any other details that might be useful (optional)

ng build --prod --no-aot will result in similar errors:

Uncaught TypeError: Assignment to constant variable. at ih._compileModule (vendor.defd7bfff770299239f9.bundle.js:1) at j.then (vendor.defd7bfff770299239f9.bundle.js:1) at Object.then (vendor.defd7bfff770299239f9.bundle.js:1) at ih._compileModuleAndComponents (vendor.defd7bfff770299239f9.bundle.js:1) at ih.compileModuleAsync (vendor.defd7bfff770299239f9.bundle.js:1) at useClass.compileModuleAsync (vendor.defd7bfff770299239f9.bundle.js:1) at ls.bootstrapModule (vendor.defd7bfff770299239f9.bundle.js:1) at Object.cDNt (main.98d929d5770520d2cd22.bundle.js:1) at o (inline.66056c9a0e270b3547d6.bundle.js:1) at Object.0 (main.98d929d5770520d2cd22.bundle.js:1)

ng build --aot is fine.

ng build is fine.

When the tsconfig.json defined target:es5, ng build --prod results in correct behavior in runtime.