feat: export is of type ESLint.Config

package.json

@@ -74,6 +74,7 @@
   "devDependencies": {
     "@commitlint/cli": "8.3.5",
     "@commitlint/travis-cli": "8.3.5",
+    "@types/eslint": "6.8.1",
     "@types/node": "14.0.5",
     "@typescript-eslint/eslint-plugin": "2.33.0",
     "ava": "3.8.2",

src/eslint-config-standard.ts

@@ -0,0 +1,6 @@
+import config from 'eslint-config-standard/eslintrc.json'
+import { Linter } from 'eslint'
+
+const casted = config as unknown as Linter.Config
+
+export default casted

src/index.test.ts

@@ -1,8 +1,9 @@
 import test from 'ava'
 import exported from '.'
-import { rules as standardRules } from 'eslint-config-standard/eslintrc.json'
+import configStandard from './eslint-config-standard'
 import standardPkg from 'eslint-config-standard/package.json'
 import readPkgUp, { NormalizedPackageJson } from 'read-pkg-up'
+import { Linter } from 'eslint'
 
 interface OurDeps {
   ourDeps: NonNullable<NormalizedPackageJson['dependencies']>
@@ -24,7 +25,7 @@ const getOurDeps = async (): Promise<OurDeps> => {
 }
 
 test('export', (t): void => {
-  const expected = {
+  const expected: Linter.Config = {
     extends: 'eslint-config-standard',
     plugins: ['@typescript-eslint'],
     overrides: [
@@ -194,19 +195,15 @@ test('Deps parser and plugin are same version', async (t) => {
   t.is(parserRange.split('^')[1], pluginRange.split('>=')[1])
 })
 
-interface RulesConfig {
-  [name: string]: object | string | number | boolean | null
-}
-
-test('No references to standard rules config', (t) => {
-  for (const override of exported.overrides) {
-    const standardRulesConfig: RulesConfig = standardRules
-    const overrideRulesConfig: RulesConfig = override.rules
+test('Exported rule values do not reference eslint-config-standard ones', (t) => {
+  if (exported.overrides === undefined) throw new Error()
+  t.is(exported.overrides.length, 1)
+  const override = exported.overrides[0]
+  if (override.rules === undefined) throw new Error()
 
-    for (const ruleName in standardRulesConfig) {
-      if (typeof standardRulesConfig[ruleName] !== 'object') continue // Non-objects use copy-by-value
+  for (const ruleName in configStandard.rules) {
+    if (typeof configStandard.rules[ruleName] !== 'object') continue // Non-objects use copy-by-value
 
-      t.not(overrideRulesConfig[`@typescript-eslint/${ruleName}`], standardRulesConfig[ruleName])
-    }
+    t.false(override.rules[`@typescript-eslint/${ruleName}`] === configStandard.rules[ruleName])
   }
 })

src/index.ts

@@ -1,4 +1,5 @@
-import { rules as standardRules } from 'eslint-config-standard/eslintrc.json'
+import configStandard from './eslint-config-standard'
+import { Linter } from 'eslint'
 
 const equivalents = [
   'comma-spacing',
@@ -19,8 +20,12 @@ const equivalents = [
   'space-before-function-paren'
 ] as const
 
-function clone<T extends object | string | number | boolean | null> (value: T): T {
-  return JSON.parse(JSON.stringify(value))
+const ruleFromStandard = (name: string): Linter.RuleEntry => {
+  if (configStandard.rules === undefined) throw new Error()
+  const rule = configStandard.rules[name]
+  if (rule === undefined) throw new Error()
+  if (typeof rule !== 'object') return rule
+  return JSON.parse(JSON.stringify(rule))
 }
 
 function fromEntries<T> (iterable: Array<[string, T]>): { [key: string]: T } {
@@ -30,7 +35,7 @@ function fromEntries<T> (iterable: Array<[string, T]>): { [key: string]: T } {
   }, {})
 }
 
-export = {
+const config: Linter.Config = {
   extends: 'eslint-config-standard',
   plugins: ['@typescript-eslint'],
   overrides: [
@@ -48,7 +53,7 @@ export = {
         'no-use-before-define': 'off',
 
         // @typescript-eslint versions of Standard.js rules:
-        ...fromEntries(equivalents.map((name) => [`@typescript-eslint/${name}`, clone(standardRules[name])])),
+        ...fromEntries(equivalents.map((name) => [`@typescript-eslint/${name}`, ruleFromStandard(name)])),
         '@typescript-eslint/no-use-before-define': ['error', {
           functions: false,
           classes: false,
@@ -121,3 +126,5 @@ export = {
     }
   ]
 }
+
+export = config