Reverted back to publishing ES5 builds. Fixes #1584

CHANGELOG.md

@@ -1,6 +1,7 @@
 # 5.0.1
 
 * Fixed regression bug: `ObservableMap.size` was no longer observable. Fixes [#1583](https://github.com/mobxjs/mobx/issues/1583)
+* Downgraded lib export from ES6 to ES5. To many build tools still trip over ES6. Fixes [#1584](https://github.com/mobxjs/mobx/issues/1584). A modern build is available through `import ... from "mobx/lib/mobx.es6"` (or setup an alias in your build system)
 * Added support for mobx-react-devtools
 
 # 5.0.0

package.json

@@ -5,6 +5,7 @@
   "main": "lib/mobx.js",
   "umd:main": "lib/mobx.umd.js",
   "module": "lib/mobx.module.js",
+  "unpkg": "lib/mobx.umd.min.js",
   "jsnext:main": "lib/mobx.module.js",
   "react-native": "lib/mobx.module.js",
   "typings": "lib/mobx.d.ts",

scripts/build.js

@@ -92,19 +92,25 @@ function copyFlowDefinitions() {
 }
 
 function build() {
-    runTypeScriptBuild(".build.cjs", ts.ScriptTarget.ES2015, true)
-    runTypeScriptBuild(".build.es", ts.ScriptTarget.ES2015, false)
+    runTypeScriptBuild(".build.es5", ts.ScriptTarget.ES5, true)
+    runTypeScriptBuild(".build.es6", ts.ScriptTarget.ES2015, false)
     return Promise.all([
         generateBundledModule(
-            path.resolve(".build.cjs", "mobx.js"),
+            path.resolve(".build.es5", "mobx.js"),
             path.resolve("lib", "mobx.js"),
             "cjs"
         ),
 
         generateBundledModule(
-            path.resolve(".build.es", "mobx.js"),
+            path.resolve(".build.es5", "mobx.js"),
             path.resolve("lib", "mobx.module.js"),
             "es"
+        ),
+
+        generateBundledModule(
+            path.resolve(".build.es6", "mobx.js"),
+            path.resolve("lib", "mobx.es6.js"),
+            "es"
         )
     ]).then(() => {
         generateUmd()