Error if process.env.WATCH is not defined

[pamls]

Error

\node_modules\fork-ts-checker-webpack-plugin\lib\service.js:49
    : new IncrementalChecker_1.IncrementalChecker(typescript, exports.createNormalizedMessageFromDiagnostic, exports.createNormalizedMessageFromRuleFailure, process.env.TSCONFIG, JSON.parse(process.env.COMPILER_OPTIONS), process.env.CONTEXT, process.env.TSLINT === 'true' ? true : process.env.TSLINT || false, process.env.TSLINTAUTOFIX === 'true', process.env.WATCH === '' ? [] : process.env.WATCH.split('|'), parseInt(process.env.WORK_NUMBER, 10) || 0, parseInt(process.env.WORK_DIVISION, 10) || 1, process.env.CHECK_SYNTACTIC_ERRORS === 'true', process.env.VUE === 'true', resolveModuleName, resolveTypeReferenceDirective);

TypeError: Cannot read property 'split' of undefined
    at Object.<anonymous> (\node_modules\fork-ts-checker-webpack-plugin\lib\service.js:49:399)
    at Module._compile (module.js:635:30)

Expected behavior

It could be good to check if process.env.WATCH is defined

Steps to reproduce the issue

I used an hello world example of Nuxt.js with nuxt-i18n

Environment

• fork-ts-checker-webpack-plugin: 1.3.7
• typescript: 3.5.3
• tslint: 5.18.0
• webpack: 4.34.0
• os: Windows 10

[johnnyreilly]

Would you like to submit a PR? I'm afraid your reproduction isn't plug and play enough for me to look at; we'd need a reproduction repo

[phryneas]

We are setting WATCH in

fork-ts-checker-webpack-plugin/src/index.ts

Line 599 in 0c93455

WATCH: this.isWatching ? this.watchPaths.join('|') : '',

before calling the service.ts.

The only way this behaviour makes sense to me would be if Windows 10 would delete environment variables with an empty string instead of keeping them. And that would have many more implications.
@johnnyreilly, if I remember correctly you're using Windows for development, right? Could you test that?

[johnnyreilly]

I am a Windows user yes - will try and check that when I get some time. (Lots going on right now 😁)

[piotr-oles]

@pamls
Please try fork-ts-checker-webpack-plugin@alpha - I've published a new version which should resolve this issue 🚀
I will close this issue to clean-up the backlog. If this release didn't solve the issue, we can re-open this :)