ESLint: TypeError: This.cliEngine is not a constructor
The cause of the error is: prior to this issue we were using a part of the ESLint API that was removed in v6.
This has already been resolved in 2019.1.3 and in all 2019.2 builds.
If you're encountering this error, please upgrade your IDE to the latest version.
The issue is with ESLint version 6.x. If upgrading Webstorm is not an option for you, you have to downgrade to ESLint version 5:
npm install --save-dev eslint@5
There's a dirty but valid hack for anyone using a fallback license and not wanting to upgrade to resolve the issue (or those who don't want to go to 5.x version of ESLint):
Wait for the this.CliEngine is not a constructor balloon to appear and click "Details"
Follow the first link in the stack-trace to eslint-plugin.js file
Find the following line at the top:
this.CliEngine = require(this.basicPath + "lib/cli-engine");
And replace it with the following one:
this.CliEngine = require(this.basicPath).CLIEngine;
Referencing and thanks to ESLint Issue and the comment: https://github.com/eslint/eslint/issues/11957#issuecomment-509261793