configFileDiag response not generated until after config file is saved

[mjbvz]

From microsoft/vscode#69880

TypeScript Version: 3.4.0-rc

Search Terms:

• configFileDiag

Repo

1. Create a simple jsconfig project with a jsconfig.json:

{
    "compilerOptions": {
        "module": "commonjs",
        "target": "es2016",
        "jsx": "preserve"
    },
    "exclude": [
        "node_modules",
    ],
    "files": []
}

And a single js file

1. Open the workspace in vscode

Expected behavior:
A config file configFileDiag result is generated when the project is first loaded

Actual behavior:
No such request is generated until the file is saved

Playground Link:

Related Issues:

[sheetalkamat]

That's because for config file change we are watching disk for changes and there is currently no notion of open config file. Probably that's what we would need to be able to detects such changes.

[mjbvz]

@sheetalkamat As a first step, could TS Server send us a configFileDiag error when it initially reads the tsconfig file from the disk?

I've opened #30674 to track synchronizing unsaved config files (mainly for error reporting)

[sheetalkamat]

@mjbvz we send the configFileDiag whenever file is opened from configured project (where it reads first) is that not what you see?

[mjbvz]

In this specific case, since files is empty, we never get configFileDiag until the jsconfig is saved. From the TS server logs, I do see that TS detects the config file:

Opened configuration file /Users/matb/projects/san/jsconfig.json

But all the js files in the workspace go into an inferred project

[sheetalkamat]

Should we send this event only when the file list we find for configured project is empty ?

[mjbvz]

That would be a good starting point. There are other config errors that can cause this too, such as using an invalid file in files (such as trying to use a glob pattern there)