[Mojo] Make javascript enums extensible.

mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl

Index: mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl
diff --git a/mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl b/mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl
index 4ae0a9b5cdb4d3b72e8aab6d64cfc9173211421d..018ca0555496601d6f5f5b6a896c8a097168d27d 100644
--- a/mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl
+++ b/mojo/public/tools/bindings/generators/js_templates/enum_definition.tmpl
@@ -1,5 +1,5 @@
 {%- macro enum_def(enum_name, enum) -%}
-  {{enum_name}} = {};
+{{enum_name}} = {};
 {%- set prev_enum = 0 %}
 {%- for field in enum.fields %}
 {%-   if field.value %}
@@ -10,4 +10,25 @@
   {{enum_name}}.{{field.name}} = {{enum_name}}.{{enum.fields[loop.index0 - 1].name}} + 1;
 {%-   endif %}
 {%- endfor %}
+
+{{enum_name}}.isKnownEnumValue = function(value) {
+{%-   if enum.fields %}
+      switch (value) {

[Ken Rockot(use gerrit already), 2016/09/30 21:51:54]

nit: 2 space indentation, not 4. Note, the jinja indentation and the templated
code indentation are independent. the jinja "if" indent is correct on the line
above, but this line should be indented  with respect to the function { block
containing it. Same indentation change applies to the rest of this generated
function and the one below.


foo = function(...) {
  // two spaces
};

+{%-     for enum_field in enum.fields|groupby('numeric_value') %}
+        case {{enum_field[0]}}:
+{%-     endfor %}
+          return true;
+      }
+{%-   endif %}
+    return false;
+  };
+
+{{enum_name}}.validate = function(enumValue) {
+    var isExtensible = {% if enum.extensible %}true{% else %}false{% endif %};
+    if (isExtensible || this.isKnownEnumValue(enumValue))
+      return validator.validationError.NONE;
+
+    return validator.validationError.UNKNOWN_ENUM_VALUE;
+  };
+
 {%- endmacro %}