[Bug]: Twice as slow when used as ESLint plugin

[screendriver]

Kind of Issue

Runtime - command-line tools

Tool or Library

cspell/eslint-plugin

Version

8.17.5

Supporting Library

Not sure / None

OS

All of them

OS Version

No response

Description

When running cspell as an ESLint plugin it is approximately twice as slow as running it directly from the CLI. Is there any particular reason why and anything we can improve here?

$ time npx cspell "source/**"
$ 4.70s user 0.91s system 70% cpu 7.996 total

compared to

eslint .
Rule                                    | Time (ms) | Relative
:---------------------------------------|----------:|--------:
@cspell/spellchecker                    | 10409.575 |    15.6%

Steps to Reproduce

Expected Behavior

No response

Additional Information

ESLint configuration:

'@cspell/spellchecker': [
    'warn',
    {
        autoFix: false,
        numSuggestions: 3,
        generateSuggestions: true,
        ignoreImports: true,
        ignoreImportProperties: true,
        checkIdentifiers: true,
        checkStrings: true,
        checkStringTemplates: true,
        checkJSXText: true,
        checkComments: true,
        cspell: {
            words: [],
            ignoreWords: [],
            flagWords: [],
            ignoreRegExpList: [],
            includeRegExpList: [],
            allowCompoundWords: true,
            import: [],
            dictionaries: []
        },
        customWordListFile: undefined,
        debugMode: false
   }
]

cspell.json

{
    "words": []
}

cspell.config.yaml

Example Repository

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[Jason3S]

@screendriver,

This is expected. ESLint takes time to parse each file before sending the text to the spell checker.

ESLint expects all plugins to be single threaded. Meaning all file reads and checks happen serially, slowing everything down.

[screendriver]

I'm not quite sure if this is really expected. ESLint is parsing the source files just one single time and then executes all plugins and rules on the generated AST. All other rules that I use are super fast and it is only cspell that is super slow. If you look at the flamegraph that I created you can see that cspell's walkTree() and walkNodes() is taking the most time over everything else. It is taking so much time that you barely can see all other ESLint plugins:

Also the ESLint builtin profile rule performance check shows this:

Rule                                    | Time (ms) | Relative
:---------------------------------------|----------:|--------:
@cspell/spellchecker                    | 10412.607 |    15.7%
@typescript-eslint/no-unsafe-assignment |  7781.353 |    11.7%
@typescript-eslint/no-misused-promises  |  7059.576 |    10.6%
import/no-cycle                         |  6323.470 |     9.5%
prettier/prettier                       |  4912.290 |     7.4%
@typescript-eslint/no-floating-promises |  4550.338 |     6.9%
import/no-deprecated                    |  4532.762 |     6.8%
@typescript-eslint/no-unsafe-return     |  1984.953 |     3.0%
node/no-restricted-import               |  1482.559 |     2.2%
import/extensions                       |  1313.177 |     2.0%