There is no issues with languages, packages, or what not.
Random code snippets from the internet are obviously completely unsafe. There is therefore basic "due diligence" to apply when considering using one such snippet:
1. Very carefully read the code to understand it.
2. Test it (corner cases/threshold values are the trivial things to test for such a piece of code doing conversions)
In general I do not copy-paste code snippets. I use them as examples of how to perform a task or how to use an API, then I write my own code.
This also avoids IP issues.
then it's never possible to use any package/module/plugin anywhere. I get the danger but I'd rather have convenience than writing every function from scratch
There is a very big, and obvious, difference between using a plugin published by a well-known source, and a random code snippet posted by a random person.
This does not tell you anything about the source of the snippet and, almost by definition, people who blindly copy snippets from SO are likely not experts in the field.
On the other hand, when I download and use Openssl (for example) I am reasonably confident that the code was developed and scrutinised by people who know what they are doing.
Random code snippets from the internet are obviously completely unsafe. There is therefore basic "due diligence" to apply when considering using one such snippet:
1. Very carefully read the code to understand it.
2. Test it (corner cases/threshold values are the trivial things to test for such a piece of code doing conversions)
In general I do not copy-paste code snippets. I use them as examples of how to perform a task or how to use an API, then I write my own code. This also avoids IP issues.