feat: enable onload callbacks (#414)

* refactor(examples): run ssr example from server

* chore: switch to babel for build

buble complains too much

* feat: enable loaded callbacks

feat: add skip option

* examples: add async-callback browser example

* examples: fix server

* examples(ssr): add reactive script with callback

* fix: also skip on ssr

* chore: remove unused var

* feat: only add mutationobserver if DOM is still loading

feat: disconnect mutation observer once DOM has loaded

* examples: pass vmid to loadCallback instead of el

* feat: also support load callbacks for link/style tags

* test: add unit tests for load

* test: add load e2e test

* chore: fix lint

* chore: remove unused files

* test: fix e2e load callback test

* test: fix attempt

* examples: ie9 compatiblity

destructuring doesnt work in ie9

* fix: add onload attribute on ssr

dont rely on mutationobserver

* chore: lint ci conf

* refactor: remove loadCallbackAttribute config option

test: fix coverage for load

* test: improve coverage

* fix: only use console when it exists (for ie9)

* chore: fix coverage

scripts/rollup.config.js

@@ -1,7 +1,7 @@
 import commonjs from 'rollup-plugin-commonjs'
 import nodeResolve from 'rollup-plugin-node-resolve'
 import json from 'rollup-plugin-json'
-import buble from 'rollup-plugin-buble'
+import babel from 'rollup-plugin-babel'
 import replace from 'rollup-plugin-replace'
 import { terser } from 'rollup-plugin-terser'
 import defaultsDeep from 'lodash/defaultsDeep'
@@ -32,8 +32,8 @@ function rollupConfig({
     }
   }
 
-  // keep simple polyfills when buble plugin is used for build
-  if (plugins && plugins.some(p => p.name === 'buble')) {
+  // keep simple polyfills when babel plugin is used for build
+  if (plugins && plugins.some(p => p.name === 'babel')) {
     replaceConfig.values = {
       'const polyfill = process.env.NODE_ENV === \'test\'': 'const polyfill = true',
     }
@@ -63,7 +63,7 @@ export default [
       file: pkg.web,
     },
     plugins: [
-      buble()
+      babel()
     ]
   },
   // minimized umd web build
@@ -72,7 +72,7 @@ export default [
       file: pkg.web.replace('.js', '.min.js'),
     },
     plugins: [
-      buble(),
+      babel(),
       terser()
     ]
   },
@@ -84,7 +84,7 @@ export default [
       format: 'cjs'
     },
     plugins: [
-      buble()
+      babel()
     ],
     external: Object.keys(pkg.dependencies)
   },
@@ -96,7 +96,7 @@ export default [
       format: 'es'
     },
     plugins: [
-      buble()
+      babel()
     ],
     external: Object.keys(pkg.dependencies)
   },