[IMP] web: add es6 class patcher

This commit implements a new way to monkey-patch ES6
classes (for instance, Owl Components).

Usage
-----

odoo.module('module.BaseClass', function (require) {
    const patchMixin = require('web.patchMixin');

    // Define your class as usual
    class BaseClass {
        constructor() {
            this.foo = 'foo';
        }
        bar() {
            console.log(this.foo);
        }
    }

    // but export it like this to have a "patchable" version
    return patchMixin(BaseClass);
});

odoo.module('module.Patch', function (require) {
    // imports the "patchable" version
    const BaseClass = require('module.BaseClass');

    BaseClass.patch('key', T =>
        class extends T {
            constructor() {
                super();
                this.foo = 'patched foo';
            }
            bar() {
                super.bar();
                console.log('patched bar()');
            }
        }
    );
});

odoo.module('module.instance', function (require) {
    // imports the "patchable" version
    const BaseClass = require('module.BaseClass');

    const obj = new BaseClass();
    obj.bar();
    // if module.patch is loaded before this module the patch
    // will be apply and calling obj.bar() will log:
    // patched foo
    // patched bar()

    // You can unpatch a patchable class
    BaseClass.unpatch('key');
});

1 files changed, 2 insertions, 0 deletions

diff --git a/addons/web/views/webclient_templates.xml b/addons/web/views/webclient_templates.xml
index 05059f15d55..275a1ccd59f 100644
--- a/addons/web/views/webclient_templates.xml
+++ b/addons/web/views/webclient_templates.xml
@@ -144,6 +144,7 @@
         <script type="text/javascript" src="/web/static/src/js/core/dom.js"></script>
         <script type="text/javascript" src="/web/static/src/js/core/local_storage.js"></script>
         <script type="text/javascript" src="/web/static/src/js/core/mixins.js"></script>
+        <script type="text/javascript" src="/web/static/src/js/core/patch_mixin.js"></script>
         <script type="text/javascript" src="/web/static/src/js/core/qweb.js"></script>
         <script type="text/javascript" src="/web/static/src/js/core/ram_storage.js"></script>
         <script type="text/javascript" src="/web/static/src/js/core/registry.js"></script>
@@ -721,6 +722,7 @@
         <script type="text/javascript" src="/web/static/tests/core/data_comparison_utils_tests.js"></script>
         <script type="text/javascript" src="/web/static/tests/core/math_utils_tests.js"></script>
         <script type="text/javascript" src="/web/static/tests/core/mixins_tests.js"></script>
+        <script type="text/javascript" src="/web/static/tests/core/patch_mixin_tests.js"></script>
         <script type="text/javascript" src="/web/static/tests/core/time_tests.js"></script>
         <script type="text/javascript" src="/web/static/tests/core/concurrency_tests.js"></script>
         <script type="text/javascript" src="/web/static/tests/core/util_tests.js"></script>