[dart][dart-dio] Prevent name collisions for fields with leading _

[kuhnroyal]

• leading underscores _ mark private fields in Dart, so until now we just removed them
• but just removing the fields can lead to name collision and missing fields
• a prominent use-case are fields id and _id which previously would result in the _id field being lost on the Dart side
• fixes [BUG] [dart-dio] _id is generated as id #14482

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CC @jaumard (2018/09) @josh-burton (2019/12) @amondnet (2019/12) @sbu-WBT (2020/12) @kuhnroyal (2020/12) @agilob (2020/12) @ahmednfwela (2021/08)

[kuhnroyal]

We still have potential collisions here and we also loose double (multiple) underscores due to the implementation of the camelize method. But I am not sure it is worth to rewrite it all.

[ahmednfwela]

how about transforming _fieldName to $_fieldName, it keeps the underscore and prevents collisions and since it doesn't start with _ it's not private
so _id would become $_id
however this generates lint warning non_constant_identifier_names

[kuhnroyal]

how about transforming _fieldName to $_fieldName, it keeps the underscore and prevents collisions and since it doesn't start with _ it's not private so _id would become $_id however this generates lint warning non_constant_identifier_names

Yea was wondering the same, not sure what happens with built_value then because it also prefixes all kinds of things with $.

[kuhnroyal]

We also convert $ to dollar

[ahmednfwela]

built value only prefixes class names with $, but it's a valid identifier to use.
also I don't know why $ gets transformed to "dollarsign" maybe we remove it in next major release

[kuhnroyal]

built value only prefixes class names with $, but it's a valid identifier to use. also I don't know why $ gets transformed to "dollarsign" maybe we remove it in next major release

Yea it probably is like that since the dawn of time because the generator just used the the Java way of things.

I am not sure how to proceed, any change, even the current one is breaking some cases but on the other hand it is also a bug...

[ahmednfwela]

well, my suggestion is that if we are going to break anyway, lets do it right
$ should be enabled back and used to escape initial _