fix: peer dependencies

- Fixes #182
- Fixes #183

package.json

@@ -59,12 +59,12 @@
     "eslint-config-standard": "^14.1.0"
   },
   "peerDependencies": {
-    "eslint": ">=6.0.1",
+    "eslint": ">=6.2.2",
     "eslint-plugin-import": ">=2.18.0",
     "eslint-plugin-node": ">=9.1.0",
     "eslint-plugin-promise": ">=4.2.1",
     "eslint-plugin-standard": ">=4.0.0",
-    "@typescript-eslint/eslint-plugin": ">=2.0.0"
+    "@typescript-eslint/eslint-plugin": ">=2.3.3"
   },
   "devDependencies": {
     "@commitlint/cli": "^8.2.0",
@@ -81,6 +81,7 @@
     "eslint-plugin-standard": "^4.0.1",
     "husky": "^3.1.0",
     "npm-run-all": "^4.1.3",
+    "read-pkg-up": "^7.0.0",
     "standard-version": "^7.0.1",
     "tsconfigs": "^4.0.1",
     "typescript": "3.6.4"

src/index.test.ts

@@ -1,5 +1,23 @@
 import test from 'ava'
 import exported from '.'
+import standardPkg from 'eslint-config-standard/package.json'
+import readPkgUp, { NormalizedPackageJson } from 'read-pkg-up'
+
+interface OurDeps {
+  ourPeerDeps: NonNullable<NormalizedPackageJson['peerDependencies']>
+  ourDevDeps: NonNullable<NormalizedPackageJson['devDependencies']>
+}
+
+const getOurDeps = async (): Promise<OurDeps> => {
+  const readResult = await readPkgUp()
+  if (readResult === undefined) { throw new Error() }
+  const ourPkg = readResult.packageJson
+  if (ourPkg.peerDependencies === undefined) { throw new Error() }
+  const ourPeerDeps = ourPkg.peerDependencies
+  if (ourPkg.devDependencies === undefined) { throw new Error() }
+  const ourDevDeps = ourPkg.devDependencies
+  return { ourPeerDeps, ourDevDeps }
+}
 
 test('export', (t): void => {
   const expected = {
@@ -92,3 +110,27 @@ test('export', (t): void => {
 
   t.deepEqual(exported, expected)
 })
+
+test('Own peerDependencies include those of eslint-config-standard', async (t) => {
+  const { ourPeerDeps } = await getOurDeps()
+  Object
+    .entries(standardPkg.peerDependencies)
+    .forEach(([_name, standardRange]) => {
+      // https://github.com/microsoft/TypeScript/pull/12253
+      const name = _name as keyof typeof standardPkg.peerDependencies
+      const ourRange = ourPeerDeps[name]
+      t.is(ourRange, standardRange)
+    })
+})
+
+test('Dependency @typescript-eslint/eslint-plugin', async (t) => {
+  const { ourPeerDeps, ourDevDeps } = await getOurDeps()
+  const peerDepPluginRange = ourPeerDeps['@typescript-eslint/eslint-plugin']
+  const devDepPluginRange = ourDevDeps['@typescript-eslint/eslint-plugin']
+  t.true(peerDepPluginRange.startsWith('>='))
+  t.true(devDepPluginRange.startsWith('^'))
+  t.is(
+    peerDepPluginRange.split('>=')[1],
+    devDepPluginRange.split('^')[1]
+  )
+})