Angular 5: ng build - -prod fails due to clean-css: Cannot read property 'line' of undefined

Question

My app is under Angular 5.2.6.

Things are normal with ng serve, but when running ng build --prod, it takes a while, before failing. The errors seem to have to do with the clean-css actions.

Error trace:

92% chunk asset optimization/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/input-source-map-tracker.js:37
if (originalPosition.line === null && line > 1 && selectorFallbacks > 0) {
                    ^

TypeError: Cannot read property 'line' of undefined
    at originalPositionFor (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/input-source-map-tracker.js:37:23)
    at originalMetadata (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/tokenizer/tokenize.js:486:43)
    at intoTokens (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/tokenizer/tokenize.js:240:75)
    at tokenize (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/tokenizer/tokenize.js:74:10)
    at fromStyles (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/read-sources.js:147:12)
    at fromString (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/read-sources.js:48:10)
    at doReadSources (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/read-sources.js:33:12)
    at readSources (/home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/reader/read-sources.js:24:10)
    at /home/khalidvm/Desktop/Workspace/Front/frontend_v2/node_modules/clean-css/lib/clean.js:99:12
    at _combinedTickCallback (internal/process/next_tick.js:95:7)
    at process._tickCallback (internal/process/next_tick.js:161:9)

It seems that it fails when cleaning css.

Here is my package.json:

{
  "name": "test",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "karma": "ng test",
    "test": "jest",
    "test:watch": "jest --watch",
    "test:ci": "jest --runInBand",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^5.2.6",
    "@angular/common": "^5.2.6",
    "@angular/compiler": "^5.2.6",
    "@angular/core": "^5.2.6",
    "@angular/forms": "^5.2.6",
    "@angular/http": "^5.2.6",
    "@angular/platform-browser": "^5.2.6",
    "@angular/platform-browser-dynamic": "^5.2.6",
    "@angular/platform-server": "^5.2.6",
    "@angular/router": "^5.2.6",
    "angular-2-local-storage": "^1.0.1",
    "angular2-drag-scroll": "1.2.6",
    "angular2-jwt": "^0.2.3",
    "angular2-multiselect-dropdown": "1.3.6",
    "bootstrap": "^3.3.7",
    "core-js": "^2.4.1",
    "file-saver": "^1.3.3",
    "font-awesome": "^4.7.0",
    "hammerjs": "^2.0.8",
    "jest-preset-angular": "^2.0.5",
    "json2typescript": "1.0.5",
    "lodash": "^4.12.0",
    "moment": "^2.18.1",
    "ng-http-interceptor": "^3.1.2",
    "ng2-smart-table": "^1.1.0",
    "ngx-bootstrap": "2.0.2",
    "ngx-filesaver": "0.0.2",
    "ngx-modialog": "^5.0.0",
    "ngx-pagination": "^3.0.1",
    "ngx-tooltip": "0.0.9",
    "npm": "^5.2.0",
    "proxy-polyfill": "^0.1.7",
    "rxjs": "^5.5.6",
    "sha1": "^1.1.1",
    "smoothscroll-polyfill": "^0.3.5",
    "web-animations-js": "^2.2.5",
    "zone.js": "^0.8.8"
  },
  "devDependencies": {
    "@angular/cli": "1.7.1",
    "@angular/compiler-cli": "^5.2.6",
    "@types/jasmine": "2.5.38",
    "@types/jest": "^20.0.5",
    "@types/node": "~6.0.60",
    "codelyzer": "~2.0.0",
    "jasmine-core": "~2.5.2",
    "jasmine-spec-reporter": "~3.2.0",
    "jest": "^20.0.4",
    "karma": "~1.4.1",
    "karma-chrome-launcher": "~2.0.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^0.2.0",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.0",
    "ts-jest": "^20.0.7",
    "ts-node": "~2.0.0",
    "tslint": "~4.5.0",
    "typescript": "2.4.2"
  },
  "jest": {
    "preset": "jest-preset-angular",
    "setupTestFrameworkScriptFile": "<rootDir>/src/setupJest.ts",
    "transformIgnorePatterns": [
      "node_modules/(?!json2typescript|angular2-multiselect-dropdown|ngx-filesaver|ngx-bootstrap|angular2-drag-scroll)"
    ]
  }
}

I've cleaned npm cache, deleted the package-lock.json, re-installed node_modules, I have also downgraded to angular-cli 1.6.8 and 1.6.8 but, with 1.6.x there is another issue which appears, therefore I was told to upgrade to 1.7.x.

But unfortenately this comes worse.

Also it's difficult to beautify manually all my css data, because I have a huge css data.

Suggestions ?

Answer 1

Run your sass/css files to show all space characters. I am pretty sure there is a non-breaking space somewhere between your properties which is causing it to break. something like

{
  color:[non-breaking-space]#123456;
}

You can spot these bad characters by installing a VS code plugin called Highlight Bad Chars https://marketplace.visualstudio.com/items?itemName=wengerk.highlight-bad-chars

Answer 2

TL;DR: Use an editor to find non-breaking spaces and eliminate them.

While it seems clean-css is failing fantastically after @angular/cli 1.6.7, this issue can be resolved for later versions of @angular/cli, regardless.

I got a lead on this issue being caused by non-breaking spaces: https://github.com/jakubpawlowicz/clean-css/issues/1006

I was then able to resolve the issue by opening the src/ folder as a workspace in Notepad++, filtering on *.scss and *.css, and doing a search with Regex on using \xA0 to find non-breaking spaces in the scss/css files; I found one. Once removed, my error went away.

For those that want to know how to accomplish this in Notepad++ in detail:

1. File > Open Folder as Workspace... ; choose your folder containing your code
2. In the Folder as Workspace window, right-click the folder and choose "Find in Files"
3. in the "Find what" window, put \xA0
4. In the "Filters" window, put *.scss *.css
5. Under the "Search Mode" field set at the bottom, select "Regular expression"
6. Click "Find All" and your offending non-breaking space locations should show up in the find window. Double-click on them to go to them and then delete and save.
7. Profit.