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

{%- macro enum_def(enum_name, enum) -%}
  {{enum_name}} = {};
{%- set prev_enum = 0 %}
{%- for field in enum.fields %}
{%-   if field.value %}
  {{enum_name}}.{{field.name}} = {{field.value|expression_to_text}};
{%-   elif loop.first %}
  {{enum_name}}.{{field.name}} = 0;
{%-   else %}
  {{enum_name}}.{{field.name}} = {{enum_name}}.{{enum.fields[loop.index0 - 1].name}} + 1;
{%-   endif %}
{%- endfor %}
{%- endmacro %}