Types: plugin and parser types incompatible with ESLint types #9110
Description
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- I have tried restarting my IDE and the issue persists.
- I have updated to the latest version of the packages.
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Issue Description
I am trying to create a type-safe ESLint config using @typescript-eslint. But it appears the types are not formatted correctly.
Here is a simplified version of what I have:
import tsESLint from 'typescript-eslint';
import type { Linter } from 'eslint';
export function config(): Linter.FlatConfig[] {
return [
{
plugins: {
// Throws type error
// The type of 'TSESLint.FlatConfig.Plugin' is not compatible with 'ESLint.Plugin'
'@typescript-eslint': tsESLint.plugin,
},
languageOptions: {
// Throws type error
// The type of 'TSESLint.Parser.LooseParserModule' is not compatible with 'Linter.FlatConfigParserModule'
parser: tsESLint.parser,
},
// ...
},
];
}Here's the error message for the plugin:
Type 'import(".../@typescript-eslint/utils/dist/ts-eslint/Config").FlatConfig.Plugin' is not assignable to type 'import("c:/Users/jstnm/OneDrive/Programming/eslint-config/node_modules/@types/eslint/index").ESLint.Plugin'.
Types of property 'configs' are incompatible.
Type 'SharedConfigs | undefined' is not assignable to type 'Record<string, FlatConfig<RulesRecord> | FlatConfig<RulesRecord>[] | ConfigData<RulesRecord>> | undefined'.
Type 'SharedConfigs' is not assignable to type 'Record<string, FlatConfig<RulesRecord> | FlatConfig<RulesRecord>[] | ConfigData<RulesRecord>>'.
'string' index signatures are incompatible.
Type 'Config' is not assignable to type 'FlatConfig<RulesRecord> | FlatConfig<RulesRecord>[] | ConfigData<RulesRecord>'.
Type 'Config' is not assignable to type 'FlatConfig<RulesRecord>'.
Types of property 'files' are incompatible.
Type '(FileSpec | FileSpec[])[] | undefined' is not assignable to type '(string | string[])[] | undefined'.
Type '(FileSpec | FileSpec[])[]' is not assignable to type '(string | string[])[]'.
Type 'FileSpec | FileSpec[]' is not assignable to type 'string | string[]'.
Type '(filePath: string) => boolean' is not assignable to type 'string | string[]'.
Here's the error message for the parser (slightly different between v7 and v8):
// typescript-eslint@7.9.0
Type 'LooseParserModule' is not assignable to type 'FlatConfigParserModule | undefined'.
Type '{ meta?: { name?: string | undefined; version?: string | undefined; } | undefined; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type 'FlatConfigParserModule | undefined'.
Type '{ meta?: { name?: string | undefined; version?: string | undefined; } | undefined; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type 'Omit<ParserModule, "parseForESLint"> & { parseForESLint(text: string, options?: any): Omit<ESLintParseResult, "ast" | "scopeManager"> & { ...; }; }'.
Type '{ meta?: { name?: string | undefined; version?: string | undefined; } | undefined; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type '{ parseForESLint(text: string, options?: any): Omit<ESLintParseResult, "ast" | "scopeManager"> & { ast: unknown; scopeManager?: unknown; }; }'.
The types returned by 'parseForESLint(...)' are incompatible between these types.
Type '{ ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }' is not assignable to type 'Omit<ESLintParseResult, "ast" | "scopeManager"> & { ast: unknown; scopeManager?: unknown; }'.
Type '{ ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }' is not assignable to type 'Omit<ESLintParseResult, "ast" | "scopeManager">'.
Types of property 'visitorKeys' are incompatible.
Type 'unknown' is not assignable to type 'VisitorKeys | undefined'.
// typescript-eslint@8.0.0-alpha.13
Type '{ meta?: { name?: string; version?: string; }; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type 'FlatConfigParserModule'.
Type '{ meta?: { name?: string; version?: string; }; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type 'Omit<ParserModule, "parseForESLint"> & { parseForESLint(text: string, options?: any): Omit<ESLintParseResult, "ast" | "scopeManager"> & { ...; }; }'.
Type '{ meta?: { name?: string; version?: string; }; parseForESLint(text: string, options?: unknown): { ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }; }' is not assignable to type '{ parseForESLint(text: string, options?: any): Omit<ESLintParseResult, "ast" | "scopeManager"> & { ast: unknown; scopeManager?: unknown; }; }'.
The types returned by 'parseForESLint(...)' are incompatible between these types.
Type '{ ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }' is not assignable to type 'Omit<ESLintParseResult, "ast" | "scopeManager"> & { ast: unknown; scopeManager?: unknown; }'.
Type '{ ast: unknown; services?: unknown; scopeManager?: unknown; visitorKeys?: unknown; }' is not assignable to type 'Omit<ESLintParseResult, "ast" | "scopeManager">'.
Types of property 'visitorKeys' are incompatible.
Type 'unknown' is not assignable to type 'VisitorKeys'.
Index signature for type 'string' is missing in type '{}'.
Cause
typescript-eslint is probably not used this way very often. The types are being held to a much higher standard of accuracy by requiring that they match ESLint's types. It appears there some are mistakes.
Workarounds
The plugin and parser can be force-typecasted to the correct type, but it is unsafe and not ideal.
Reproduction Repository Link
https://github.com/JstnMcBrd/typescript-eslint-repro
Repro Steps
- clone the repo
npm install
optionally, change versions withnpm install typescript-eslint@8.0.0-alpha.13npm run build
Versions
| package | versions |
|---|---|
typescript-eslint |
7.9.0 (latest), 8.0.0-alpha.13 (next) |
TypeScript |
5.4.5 (latest) |
node |
20.13.1 (LTS) |