📄 `config-helper`¶

📊 Analysis Summary¶

Metric	Count
🔧 Functions	3
📦 Imports	1
📐 Interfaces	1
📑 Type Aliases	2

📚 Table of Contents¶

Imports
Functions
Interfaces
Type Aliases

🛠️ File Location:¶

📂 packages/typescript-eslint/src/config-helper.ts

📦 Imports¶

Name	Source
`TSESLint`	`@typescript-eslint/utils`

Functions¶

`config(configs: InfiniteDepthConfigWithExtends[]): ConfigArray`¶

Utility function to make it easy to strictly type your "Flat" config file

⚠️ DEPRECATED: ESLint core now provides this functionality via defineConfig(), which we now recommend instead. See https.

Examples:

```js
//

Tags: @ts-check import js from '@eslint/js'; import tseslint from 'typescript-eslint';

export default tseslint.config( js.configs.recommended, tseslint.configs.recommended, { rules: { '@typescript-eslint/array-type': 'error', }, }, );

<details><summary>Raw JSDoc</summary>

```typescript
/**
 * Utility function to make it easy to strictly type your "Flat" config file
 * @example
 * ```js
 * // @ts-check
 *
 * import js from '@eslint/js';
 * import tseslint from 'typescript-eslint';
 *
 * export default tseslint.config(
 *   js.configs.recommended,
 *   tseslint.configs.recommended,
 *   {
 *     rules: {
 *       '@typescript-eslint/array-type': 'error',
 *     },
 *   },
 * );
 * ```
 *
 * @deprecated ESLint core now provides this functionality via `defineConfig()`,
 * which we now recommend instead. See {@link https://typescript-eslint.io/packages/typescript-eslint/#config-deprecated}.
 */

Calls:

configImpl

Code

export function config(
  ...configs: InfiniteDepthConfigWithExtends[]
): ConfigArray {
  return configImpl(...configs);
}

`configImpl(configs: unknown[]): ConfigArray`¶

Parameters:

configs unknown[]

Returns: ConfigArray

Calls:

configs.flat
flattened.flatMap
complex_call_4025
Array.isArray
(extendsArr as unknown[]).flat
extendsArrFlattened.entries
JSON.stringify
nonObjectExtensions.push
nonObjectExtensions.join
[name, extension.name] .filter(Boolean) .join
isPossiblyGlobalIgnores
configArray.push

Internal Comments:

// Unless the object is a config object with extends key, just forward it
// along to eslint.
// If the extends value is nullish, just forward along the rest of the
// config object to eslint.
// special error message to be clear we don't support eslint's stringly typed extends.
// https://eslint.org/docs/latest/use/configure/configuration-files#extending-configurations
// https://github.com/eslint/rewrite/blob/82d07fd0e8e06780b552a41f8bcbe2a4f8741d42/packages/config-helpers/src/define-config.js#L448-L450
// If it's a global ignores, then just pass it along (x4)
// If the base config could form a global ignores object, then we mustn't include
// it in the output. Otherwise, we must add it in order for it to have effect.

Code

function configImpl(...configs: unknown[]): ConfigArray {
  const flattened = configs.flat(Infinity);
  return flattened.flatMap(
    (
      configWithExtends,
      configIndex,
    ): TSESLint.FlatConfig.Config | TSESLint.FlatConfig.Config[] => {
      if (
        configWithExtends == null ||
        typeof configWithExtends !== 'object' ||
        !('extends' in configWithExtends)
      ) {
        // Unless the object is a config object with extends key, just forward it
        // along to eslint.
        return configWithExtends as TSESLint.FlatConfig.Config;
      }

      const { extends: extendsArr, ..._config } = configWithExtends;
      const config = _config as {
        name?: unknown;
        extends?: unknown;
        files?: unknown;
        ignores?: unknown;
        basePath?: unknown;
      };

      if (extendsArr == null) {
        // If the extends value is nullish, just forward along the rest of the
        // config object to eslint.
        return config as TSESLint.FlatConfig.Config;
      }

      const name = ((): string | undefined => {
        if ('name' in configWithExtends && configWithExtends.name != null) {
          if (typeof configWithExtends.name !== 'string') {
            throw new Error(
              `tseslint.config(): Config at index ${configIndex} has a 'name' property that is not a string.`,
            );
          }
          return configWithExtends.name;
        }
        return undefined;
      })();
      const nameErrorPhrase =
        name != null ? `, named "${name}",` : ' (anonymous)';

      if (!Array.isArray(extendsArr)) {
        throw new TypeError(
          `tseslint.config(): Config at index ${configIndex}${nameErrorPhrase} has an 'extends' property that is not an array.`,
        );
      }

      const extendsArrFlattened = (extendsArr as unknown[]).flat(Infinity);

      const nonObjectExtensions = [];
      for (const [extensionIndex, extension] of extendsArrFlattened.entries()) {
        // special error message to be clear we don't support eslint's stringly typed extends.
        // https://eslint.org/docs/latest/use/configure/configuration-files#extending-configurations
        if (typeof extension === 'string') {
          throw new Error(
            `tseslint.config(): Config at index ${configIndex}${nameErrorPhrase} has an 'extends' array that contains a string (${JSON.stringify(extension)}) at index ${extensionIndex}.` +
              " This is a feature of eslint's `defineConfig()` helper and is not supported by typescript-eslint." +
              ' Please provide a config object instead.',
          );
        }
        if (extension == null || typeof extension !== 'object') {
          nonObjectExtensions.push(extensionIndex);
          continue;
        }

        // https://github.com/eslint/rewrite/blob/82d07fd0e8e06780b552a41f8bcbe2a4f8741d42/packages/config-helpers/src/define-config.js#L448-L450
        if ('basePath' in extension) {
          throw new TypeError(
            `tseslint.config(): Config at index ${configIndex}${nameErrorPhrase} has an 'extends' array that contains a config with a 'basePath' property at index ${extensionIndex}.` +
              ` 'basePath' in 'extends' is not allowed.`,
          );
        }

        if ('extends' in extension) {
          throw new TypeError(
            `tseslint.config(): Config at index ${configIndex}${nameErrorPhrase} has an 'extends' array that contains a config with an 'extends' property at index ${extensionIndex}.` +
              ` Nested 'extends' is not allowed.`,
          );
        }
      }
      if (nonObjectExtensions.length > 0) {
        const extensionIndices = nonObjectExtensions.join(', ');
        throw new TypeError(
          `tseslint.config(): Config at index ${configIndex}${nameErrorPhrase} contains non-object` +
            ` extensions at the following indices: ${extensionIndices}.`,
        );
      }

      const configArray = [];

      for (const _extension of extendsArrFlattened) {
        const extension = _extension as {
          name?: unknown;
          files?: unknown;
          ignores?: unknown;
        };

        const resolvedConfigName = [name, extension.name]
          .filter(Boolean)
          .join('__');
        if (isPossiblyGlobalIgnores(extension)) {
          // If it's a global ignores, then just pass it along
          configArray.push({
            ...extension,
            ...(resolvedConfigName !== '' ? { name: resolvedConfigName } : {}),
          });
        } else {
          configArray.push({
            ...extension,
            ...(config.files ? { files: config.files } : {}),
            ...(config.ignores ? { ignores: config.ignores } : {}),
            ...(config.basePath ? { basePath: config.basePath } : {}),
            ...(resolvedConfigName !== '' ? { name: resolvedConfigName } : {}),
          });
        }
      }

      // If the base config could form a global ignores object, then we mustn't include
      // it in the output. Otherwise, we must add it in order for it to have effect.
      if (!isPossiblyGlobalIgnores(config)) {
        configArray.push(config);
      }

      return configArray as ConfigArray;
    },
  );
}

`isPossiblyGlobalIgnores(config: object): boolean`¶

This utility function returns false if the config objects contains any field that would prevent it from being considered a global ignores object and true otherwise. Note in particular that the ignores field may not be present and the return value can still be true.

Raw JSDoc

/**
 * This utility function returns false if the config objects contains any field
 * that would prevent it from being considered a global ignores object and true
 * otherwise. Note in particular that the `ignores` field may not be present and
 * the return value can still be true.
 */

Calls:

Object.keys(config).every
['name', 'ignores', 'basePath'].includes

Code

function isPossiblyGlobalIgnores(config: object): boolean {
  return Object.keys(config).every(key =>
    ['name', 'ignores', 'basePath'].includes(key),
  );
}

Interfaces¶

`ConfigWithExtends`¶

Interface Code

export interface ConfigWithExtends extends TSESLint.FlatConfig.Config {
  /**
   * Allows you to "extend" a set of configs similar to `extends` from the
   * classic configs.
   *
   * This is just a convenience short-hand to help reduce duplication.
   *
   * ```js
   * export default tseslint.config({
   *   files: ['** /*.ts'],
   *   extends: [
   *     js.configs.recommended,
   *     tseslint.configs.recommended,
   *   ],
   *   rules: {
   *     '@typescript-eslint/array-type': 'error',
   *     '@typescript-eslint/consistent-type-imports': 'error',
   *   },
   * })
   *
   * // expands to
   *
   * export default [
   *   {
   *     ...js.configs.recommended,
   *     files: ['** /*.ts'],
   *   },
   *   ...tseslint.configs.recommended.map(conf => ({
   *     ...conf,
   *     files: ['** /*.ts'],
   *   })),
   *   {
   *     files: ['** /*.ts'],
   *     rules: {
   *       '@typescript-eslint/array-type': 'error',
   *       '@typescript-eslint/consistent-type-imports': 'error',
   *     },
   *   },
   * ]
   * ```
   */
  extends?: InfiniteDepthConfigWithExtends[];
}

Properties¶

Name	Type	Optional	Description
`extends`	`InfiniteDepthConfigWithExtends[]`	✓	not shown

Type Aliases¶

`InfiniteDepthConfigWithExtends`¶

type InfiniteDepthConfigWithExtends = ConfigWithExtends | InfiniteDepthConfigWithExtends[];

`ConfigArray`¶

type ConfigArray = TSESLint.FlatConfig.ConfigArray;

Generated by Syntax Scribe

📄 config-helper¶

📊 Analysis Summary¶

📚 Table of Contents¶

🛠️ File Location:¶

📦 Imports¶

Functions¶

config(configs: InfiniteDepthConfigWithExtends[]): ConfigArray¶

configImpl(configs: unknown[]): ConfigArray¶

isPossiblyGlobalIgnores(config: object): boolean¶

Interfaces¶

ConfigWithExtends¶

Properties¶

Type Aliases¶

InfiniteDepthConfigWithExtends¶

ConfigArray¶

📄 `config-helper`¶

`config(configs: InfiniteDepthConfigWithExtends[]): ConfigArray`¶

`configImpl(configs: unknown[]): ConfigArray`¶

`isPossiblyGlobalIgnores(config: object): boolean`¶

`ConfigWithExtends`¶

`InfiniteDepthConfigWithExtends`¶

`ConfigArray`¶