Issue #10984 has been updated by Koichi Sasada.
Discussion: https://docs.google.com/document/d/1D0Eo5N7NE_unIySOKG9lVj_eyXf66BQPM4PKp7NvMyQ/pub
Feel free to continue discussion on this ticket.
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Feature #10984: Hash#contain? to check whether hash contains other hash
https://bugs.ruby-lang.org/issues/10984#change-54779
* Author: Olivier Lacan
* Status: Open
* Priority: Normal
* Assignee: Akira Tanaka
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Comparing hashes seems like a common practice but there currently isn't a method to ask a
hash instance whether it includes another hash instance.
The most intuitive method to reach for would be `Hash#include?` but it is in fact an alias to `Hash#has_key?`
What I'm looking for can be achieved with:
~~~
class Hash
def contain?(other)
self.merge(other) == self
end
end
~~~
Here's a simple demo of `#contain?` in use:
~~~
{ a: true, b: false }.contain?({ a: true})
# => true
{ a: true, b: false }.contain?({ b: false})
# => true
{ a: true, b: false }.contain?({ a: false})
# => false
{ a: true, b: false }.contain?({ c: true})
# => false
~~~
One important note is that this method is *not checking for nested hash matches*.
This may need to be addressed when the parameters include a nested hash perhaps.
Thanks to Terence Lee's help, nobu created a patch for this feature last year.
I've only modified the name of the method from [his original patch](https://gist.github.com/nobu/dfe8ba14a48fc949f2ed) and attached it to this issue.
---Files--------------------------------
Hash#contain_.patch (2.22 KB)
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