cc @uniqueiniquity - it looks like maybe we haven't handled watch mode well enough?

Yeah... this makes sense to me. Currently, once we determine the source files of a tsconfig, we won't add to it - that is, we're not watching for new files in case we need to update.

how does vscode's typescript integration do it?
I'm guessing there's support we need to specifically build in for watch mode?

In VS Code, we use TSServer, which handles of the file watching, project creation, and everything else. What we do in typescript-estree is at a lower level in the TS architecture, where we interact directly with the Node API for the TS compiler itself. By stepping up to a higher level of the TS architecture, we'd get more pieces handled for us (including this file watching piece), but may incur more performance overhead.

interesting. We should probably look into the mechanisms that the eslint vscode plugin uses to setup its watch mode - maybe there's something we can listen to to help inform how we watch.

I should note that this is actually also happening during the Webpack build, i.e. eslint-loader reports the same error as the VSCode extension for new files. I didn't notice that until now.

If it's happening during webpack watch mode, then it's the same issue.

If it's happening on a single build - then your tsconfig isn't including the files.

I'm seeing this behaviour in IntelliJ as well, so I suspect they share a root cause.

I'd image WebStorms handling of TS is similar enough to vscodes that the same fix should work for both, but someone like @prigara would be able to tell you for sure (+ I figure they'd interested in knowing about this issue).

Since there isn't way to restart the eslint service (WEB-38066 wink wink nudge nudge), I have to open & close the project everytime I add a new file in some places.

No pressure or nothing, but this is actually super annoying 😂

Let me know if there's anything I can do to help - happy to do testing & what-have-you w/ IntelliJ/WebStorm on my end, and can report an issue on YouTrack if needed 🙂

On a side note: would it be possible/worth having an option to revert back to the pre-2.0.0 behaviour in the meantime?

@G-Rath see the information in #890
Please make sure that first you can do a CLI run without any parsing errors.

If that's working for you, then feel free to add createDefaultProgram to your config. (See parser docs for more info on this option and why you shouldn't use it unless you really have to).

We're going to look into a proper fix.

@bradzacher thanks for the link - I didn't see that issue, but I did see the includes thing in the release notes.

I've confirmed that in this project, running npm run lint gives:

js-bugs@0.0.0 lint C:\Users\G-Rath\workspace\projects-personal\js-bugs
eslint "**/*.{t,j}s{x,}"

C:\Users\G-Rath\workspace\projects-personal\js-bugs\src\index.ts
0:0 error Parsing error: If "parserOptions.project" has been set for @typescript-eslint/parser, C:\Users\G-Rath\workspace\projects-personal\js-bugs\src\index.ts must be included in at least one of the projects provided

✖ 1 problem (1 error, 0 warnings)

As expected since src isn't included, but WebStorm gives that if I make a new .ts file in configs/, which is included via tsconfig.eslint.json.

createDefaultProgram: true fixes this as expected.

Let me know if you'd like me to make a new webstorm-specific issue 🙂

I only raised #890 this morning, to try and consolidate the discussion going forward because people were commenting on closed issues.

Yup, it doesn't matter if it's via eslint --watch, or via an IDE plugin - the mechanism is essentially the same. ESLint runs continually, and sends files to our parser.

Because eslint never "dies", our parser maintains its state - you launch the IDE, it starts eslint, which triggers our parser, which triggers typescript and detects all of the valid files matched by your tsconfig.

This is great for existing files, as we only need to do a small bit of work when you update the file.

However with new files, it means that our project state doesn't contain the brand new file. Unfortunately, we don't currently have a mechanism for telling typescript to "rescan" the workspace to detect new files. Which means ofc your file just throws an error.

createDefaultProgram essentially allows the parser to use old code path. This means that when the parser detects a file that hasn't been parsed, it treats it as the root of a new program, and parses the file and its dependencies. Less performant by a long shot, but covers all the bases.
The reason that it's bad turning this function on, is because you could get caught with a slow lint outside of the IDE because you added a file that's not included in your tsconfig. So yeah, use it with caution! It'll unblock you fine though.

We will figure out how to build the "rescan" functionality above, so that you can turn off createDefaultProgram.

Yup, it doesn't matter if it's via eslint --watch, or via an IDE plugin - the mechanism is essentially the same. ESLint runs continually, and sends files to our parser.

That's interesting, b/c it's fine if I do eslint config/index3.ts or run npm run lint, which is what I'd expect IDE plugins & tools to be doing if not eslint --watch.

We will figure out how to build the "rescan" functionality above, so that you can turn off createDefaultProgram.

Looking forward to it - as always, let me know if I can do anything to help (but I suspect in this case I'll be less able to help than w/ rewriting indent & co) 🙂

btw thanks for the quick & detailed responses!

In a nutshell, you'll probably find that the IDEs use eslint's internal APIs to trigger a parse of the file based on the file contents the IDE loaded. This is how they do parses whilst you're still typing without saving!

In the interest of saving time and memory however, the IDE will essentially maintain its NodeJS instance, so as far as our parser is concerned - it's one big, long, continuous, never ending lint session.

https://eslint.org/docs/developer-guide/nodejs-api#cliengineexecuteontext

const cli = new CLIEngine(require('.eslintrc.js'));

ide.onFileContentChange((contents, filename) => {
  const report = cli.executeOnText(contents, filename);
});

Hey all – just checking in if there's an ETA or a workaround patch... finding that this error is leading developers to disable linting in their IDEs completely. Should we step down to 1.13 in the meantime or is a fix close? Thanks for all the work on this!

not sure if it's a workaround, exactly, but I use cmd+shift+p and then Developer: Reload Window to get it to pick up new files I've created. It's definitely not ideal, but seems way easier than either downgrading or disabling linting.

The workaround is createDefaultProgram: true added to parserOptions in your eslint config, mentioned in comments about halfway down this page.

Now that the file watching has been added, it should no longer be necessary to use createDefaultProgram: true as a way to avoid errors for new files.

createDefaultProgram: true should be avoided whenever possible as it can mask incorrect file glob configurations by users and leads to potentially huge performance hits on lint runs.

When do you plan to release it? :)

https://github.com/typescript-eslint/typescript-eslint/blob/master/README.md#package-versions

Automated release schedule is listed in the readme.

Thanks!

@bradzacher this is still occurring in Intellij on the latest 2.4.0 (https://github.com/typescript-eslint/typescript-eslint/releases/tag/v2.4.0) which includes your PR #973

Versions

please raise a new issue with some repro steps.
"this is still occurring" doesn't provide any information for us to debug or investigate.