Angular 4.4.6生产构建失败（TS1128错误）：Bug还是配置问题？

Let's dig into the two weird behaviors you're seeing with Angular 4.4.6, CLI, and @ngtools/webpack—I've dealt with similar quirks in older Angular versions, so here's what's likely going on:

1. Random successful builds despite invalid TypeScript syntax #

First off, those inconsistent builds with extra braces or commas aren't your imagination. Older Angular CLI versions (paired with Angular 4, that's CLI ~1.4.x) and @ngtools/webpack had some real quirks in dev mode compilation:

• Dev mode takes shortcuts: ng serve prioritizes speed over strict checking to keep reloads fast. Sometimes minor syntax slip-ups (like trailing commas, which TypeScript 2.4—used in Angular 4—actually supports in many cases, or misplaced braces that don't break the parser completely) get overlooked. The inconsistency comes down to whether the incremental compiler decides to re-check the full file or relies on cached data from a previous valid build.
• Cache glitches: If you had a valid build before adding the bad syntax, the CLI's cache might hang onto that valid version instead of re-compiling the broken file properly. That's why you can't pin down a trigger—it depends on what's in the cache when you make the mistake.
• Old tooling bugs: Angular 4.4.6 and its matching CLI are pretty outdated, and there were known issues with @ngtools/webpack not enforcing strict syntax checks consistently in dev mode. Some errors that should fail a build just slipped through the cracks in these versions.

To test this theory:

• Run a full production build with ng build --prod—this enables strict, full compilation, so any invalid syntax should fail every time here.
• Wipe the CLI cache: Delete the .angular-cli folder and node_modules/.cache, then try building with the bad syntax again. If it fails now, the cache was definitely the culprit.

2. Live reload works fine after code changes #

This makes total sense. When you modify a file and trigger a live reload, the CLI does an incremental recompile of that specific file from a fresh state—no cached valid version to fall back on. So even if a previous build let bad syntax slip through, the reload catches the current file's state correctly and updates as expected. The live reload mechanism itself is working; your problem is isolated to the initial build/cache behavior.

How to tell if it's a bug or your config #

• Check your tsconfig.json: Look for flags like strict, noImplicitAny, or skipLibCheck. If strict is disabled, TypeScript is way more lenient and might let certain invalid syntax slide. Tweaking these to be stricter could make the builds fail consistently when there's bad code.
• Upgrade to Angular 4.4.10: That's the final patch for Angular 4, and it includes fixes for some compilation bugs in older 4.x versions. Upgrading might resolve the inconsistent build behavior.
• Test with a fresh project: Spin up a new Angular 4.4.6 project using the same CLI version, add the same bad syntax, and see if you can reproduce the issue. If you can, it's definitely a tooling bug in that version combo. If not, your project's custom config (like modified webpack settings, third-party libraries, or tweaked CLI options) is causing the problem.

内容的提问来源于stack exchange，提问作者BSchnitzel