Make the fuchsia mojo/public repo the source of truth.

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

-{#--- Begin #}
-  function {{struct.name}}(values) {
-    this.initDefaults_();
-    this.initFields_(values);
-  }
-
-{#--- Enums #}
-{%- from "enum_definition.tmpl" import enum_def %}
-{%  for enum in struct.enums %}
-  {{enum_def("%s.%s"|format(struct.name, enum.name), enum)}}
-{%-  endfor %}
-
-{#--- Constants #}
-{%  for constant in struct.constants %}
-  {{struct.name}}.{{constant.name}} = {{constant.value|expression_to_text}};
-{%-  endfor %}
-
-{#--- initDefaults() #}
-  {{struct.name}}.prototype.initDefaults_ = function() {
-{%- for packed_field in struct.packed.packed_fields %}
-    this.{{packed_field.field.name}} = {{packed_field.field|default_value}};
-{%- endfor %}
-  };
-
-{#--- initFields() #}
-  {{struct.name}}.prototype.initFields_ = function(fields) {
-    for(var field in fields) {
-        if (this.hasOwnProperty(field))
-          this[field] = fields[field];
-    }
-  };
-
-{#--- Validation #}
-
-  {{struct.name}}.validate = function(messageValidator, offset) {
-    var err;
-    err = messageValidator.validateStructHeader(offset, {{struct.name}}.encodedSize, {{struct.versions[-1].version}});
-    if (err !== validator.validationError.NONE)
-        return err;
-
-{%- from "validation_macros.tmpl" import validate_struct_field %}
-{%- for packed_field in struct.packed.packed_fields %}
-{%-   set offset = packed_field|field_offset %}
-{%-   set field = packed_field.field %}
-{%-   set name = struct.name ~ '.' ~ field.name %}
-{{validate_struct_field(field, offset, name)|indent(4)}}
-{%- endfor %}
-
-    return validator.validationError.NONE;
-  };
-
-{#--- Encoding and decoding #}
-
-  {{struct.name}}.encodedSize = codec.kStructHeaderSize + {{struct.packed|payload_size}};
-
-  {{struct.name}}.decode = function(decoder) {
-    var packed;
-    var val = new {{struct.name}}();
-    var numberOfBytes = decoder.readUint32();
-    var version = decoder.readUint32();
-{%- for byte in struct.bytes %}
-{%-   if byte.packed_fields|length > 1 %}
-    packed = decoder.readUint8();
-{%-     for packed_field in byte.packed_fields %}
-    val.{{packed_field.field.name}} = (packed >> {{packed_field.bit}}) & 1 ? true : false;
-{%-     endfor %}
-{%-   else %}
-{%-     for packed_field in byte.packed_fields %}
-    val.{{packed_field.field.name}} = decoder.{{packed_field.field.kind|decode_snippet}};
-{%-     endfor %}
-{%-   endif %}
-{%-   if byte.is_padding %}
-    decoder.skip(1);
-{%-   endif %}
-{%- endfor %}
-    return val;
-  };
-
-  {{struct.name}}.encode = function(encoder, val) {
-    var packed;
-    encoder.writeUint32({{struct.name}}.encodedSize);
-    encoder.writeUint32({{struct.versions[-1].version}});
-
-{%- for byte in struct.bytes %}
-{%-   if byte.packed_fields|length > 1 %}
-    packed = 0;
-{%-     for packed_field in byte.packed_fields %}
-    packed |= (val.{{packed_field.field.name}} & 1) << {{packed_field.bit}}
-{%-     endfor %}
-    encoder.writeUint8(packed);
-{%-   else %}
-{%-     for packed_field in byte.packed_fields %}
-    encoder.{{packed_field.field.kind|encode_snippet}}val.{{packed_field.field.name}});
-{%-     endfor %}
-{%-   endif %}
-{%-   if byte.is_padding %}
-    encoder.skip(1);
-{%-   endif %}
-{%- endfor %}
-  };