Throw errors on wrong feature and region names from Can I Use (#714)

* Throw an error on wrong region name from Can I Use

* Throw an error on wrong feature name from Can I Use

node.js

@@ -243,7 +243,12 @@ module.exports = {
   loadCountry: function loadCountry(usage, country, data) {
     var code = country.replace(/[^\w-]/g, '')
     if (!usage[code]) {
-      var compressed = require('caniuse-lite/data/regions/' + code + '.js')
+      var compressed
+      try {
+        compressed = require('caniuse-lite/data/regions/' + code + '.js')
+      } catch (e) {
+        throw new BrowserslistError("Unknown region name `" + code + "`.")
+      }
       var usageData = region(compressed)
       normalizeUsageData(usageData, data)
       usage[country] = {}
@@ -258,8 +263,12 @@ module.exports = {
   loadFeature: function loadFeature(features, name) {
     name = name.replace(/[^\w-]/g, '')
     if (features[name]) return
-
-    var compressed = require('caniuse-lite/data/features/' + name + '.js')
+    var compressed
+    try {
+      compressed = require('caniuse-lite/data/features/' + name + '.js')
+    } catch (e) {
+      throw new BrowserslistError("Unknown feature name `" + name + "`.")
+    }
     var stats = feature(compressed).stats
     features[name] = {}
     for (var i in stats) {

test/country.test.js

@@ -1,5 +1,5 @@
 let { test } = require('uvu')
-let { is, equal } = require('uvu/assert')
+let { is, equal, throws } = require('uvu/assert')
 
 delete require.cache[require.resolve('..')]
 let browserslist = require('..')
@@ -71,10 +71,18 @@ test('loads country from Can I Use', () => {
   is(browserslist('> 1% in RU').length > 0, true)
 })
 
+test('throw an error on wrong country name from Can I Use', () => {
+  throws(() => browserslist('> 1% in __'), /Unknown region name/)
+})
+
 test('loads continents from Can I Use', () => {
   is(browserslist('> 1% in alt-AS').length > 0, true)
 })
 
+test('throw an error on wrong continent name from Can I Use', () => {
+  throws(() => browserslist('> 1% in alt-__'), /Unknown region name/)
+})
+
 test('allows omission of the space between the > and the percentage', () => {
   is(browserslist('>10% in US').length > 0, true)
 })

test/feature.test.js

@@ -1,5 +1,5 @@
 let { test } = require('uvu')
-let { equal, is } = require('uvu/assert')
+let { equal, is, throws } = require('uvu/assert')
 
 delete require.cache[require.resolve('..')]
 let browserslist = require('..')
@@ -24,6 +24,10 @@ test('load features from Can I Use', () => {
   is(browserslist('supports objectrtc').length > 0, true)
 })
 
+test('throw an error on wrong feature name from Can I Use', () => {
+  throws(() => browserslist('supports wrong-feature-name'), /Unknown feature name/)
+})
+
 test('selects browsers by feature', () => {
   browserslist.cache = {
     rtcpeerconnection: {