Using this example code below:
_renderAttachments(attachments = []) {
return attachments.map((attach) => {
DeepCode will warn that calling .map() on non array object for attachments will not work.
It suggests to use (attachments || []). While this is correct, it does not account for the function parameter default value which is already provided.
In the above case, the function already provides a fallback for (attachments = []), so the suggested change would offer no further benefit.
This also occurs for things like Object fallbacks (attachments = {}), or es6 Object types such as (attachments = new Map())