Explicitly resolve lowest browser version (#121)

stop relying on browserlist returning a list sorted by browser version
fix #119

src/index.js

@@ -77,8 +77,10 @@ const browserNameMap = {
 const getLowestVersions = (browsers) => {
   return browsers.reduce((all, browser) => {
     const [browserName, browserVersion] = browser.split(" ");
-    if (browserName in browserNameMap) {
-      all[browserNameMap[browserName]] = parseInt(browserVersion);
+    const normalizedBrowserName = browserNameMap[browserName];
+    const parsedBrowserVersion = parseInt(browserVersion);
+    if (normalizedBrowserName && !isNaN(parsedBrowserVersion)) {
+      all[normalizedBrowserName] = Math.min(all[normalizedBrowserName] || Infinity, parsedBrowserVersion);
     }
     return all;
   }, {});

test/fixtures/preset-options/ios-10/actual.js

@@ -0,0 +1 @@
+const a = () => 1;

test/fixtures/preset-options/ios-10/expected.js

@@ -0,0 +1 @@
+const a = () => 1;

test/fixtures/preset-options/ios-10/options.json

@@ -0,0 +1,10 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "browsers": ["ios >= 10"]
+      },
+      "modules": false
+    }]
+  ]
+}

test/fixtures/preset-options/ios-6/actual.js

@@ -0,0 +1 @@
+import "core-js";

test/fixtures/preset-options/ios-6/expected.js

@@ -0,0 +1,77 @@
+import "core-js/modules/es6.typed.uint8-clamped-array";
+import "core-js/modules/es6.map";
+import "core-js/modules/es6.set";
+import "core-js/modules/es6.weak-map";
+import "core-js/modules/es6.weak-set";
+import "core-js/modules/es6.reflect.apply";
+import "core-js/modules/es6.reflect.construct";
+import "core-js/modules/es6.reflect.define-property";
+import "core-js/modules/es6.reflect.delete-property";
+import "core-js/modules/es6.reflect.get";
+import "core-js/modules/es6.reflect.get-own-property-descriptor";
+import "core-js/modules/es6.reflect.get-prototype-of";
+import "core-js/modules/es6.reflect.has";
+import "core-js/modules/es6.reflect.is-extensible";
+import "core-js/modules/es6.reflect.own-keys";
+import "core-js/modules/es6.reflect.prevent-extensions";
+import "core-js/modules/es6.reflect.set";
+import "core-js/modules/es6.reflect.set-prototype-of";
+import "core-js/modules/es6.promise";
+import "core-js/modules/es6.symbol";
+import "core-js/modules/es6.object.assign";
+import "core-js/modules/es6.object.is";
+import "core-js/modules/es6.object.set-prototype-of";
+import "core-js/modules/es6.function.name";
+import "core-js/modules/es6.string.raw";
+import "core-js/modules/es6.string.from-code-point";
+import "core-js/modules/es6.string.code-point-at";
+import "core-js/modules/es6.string.repeat";
+import "core-js/modules/es6.string.starts-with";
+import "core-js/modules/es6.string.ends-with";
+import "core-js/modules/es6.string.includes";
+import "core-js/modules/es6.regexp.flags";
+import "core-js/modules/es6.regexp.match";
+import "core-js/modules/es6.regexp.replace";
+import "core-js/modules/es6.regexp.split";
+import "core-js/modules/es6.regexp.search";
+import "core-js/modules/es6.array.from";
+import "core-js/modules/es6.array.of";
+import "core-js/modules/es6.array.copy-within";
+import "core-js/modules/es6.array.find";
+import "core-js/modules/es6.array.find-index";
+import "core-js/modules/es6.array.fill";
+import "core-js/modules/es6.array.iterator";
+import "core-js/modules/es6.number.is-finite";
+import "core-js/modules/es6.number.is-integer";
+import "core-js/modules/es6.number.is-safe-integer";
+import "core-js/modules/es6.number.is-nan";
+import "core-js/modules/es6.number.epsilon";
+import "core-js/modules/es6.number.min-safe-integer";
+import "core-js/modules/es6.number.max-safe-integer";
+import "core-js/modules/es6.math.acosh";
+import "core-js/modules/es6.math.asinh";
+import "core-js/modules/es6.math.atanh";
+import "core-js/modules/es6.math.cbrt";
+import "core-js/modules/es6.math.clz32";
+import "core-js/modules/es6.math.cosh";
+import "core-js/modules/es6.math.expm1";
+import "core-js/modules/es6.math.fround";
+import "core-js/modules/es6.math.hypot";
+import "core-js/modules/es6.math.imul";
+import "core-js/modules/es6.math.log1p";
+import "core-js/modules/es6.math.log10";
+import "core-js/modules/es6.math.log2";
+import "core-js/modules/es6.math.sign";
+import "core-js/modules/es6.math.sinh";
+import "core-js/modules/es6.math.tanh";
+import "core-js/modules/es6.math.trunc";
+import "core-js/modules/es7.array.includes.js";
+import "core-js/modules/es7.object.values";
+import "core-js/modules/es7.object.entries";
+import "core-js/modules/es7.object.get-own-property-descriptors";
+import "core-js/modules/es7.string.pad-start";
+import "core-js/modules/es7.string.pad-end";
+import "core-js/modules/web.timers";
+import "core-js/modules/web.immediate";
+import "core-js/modules/web.dom.iterable";
+import "regenerator-runtime/runtime";

test/fixtures/preset-options/ios-6/options.json

@@ -0,0 +1,11 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "browsers": ["ios >= 6"]
+      },
+      "modules": false,
+      "useBuiltIns": true
+    }]
+  ]
+}