From: "Earlopain (Earlopain _) via ruby-core" <ruby-core@...>
Date: 2025-12-14T18:33:10+00:00
Subject: [ruby-core:124198] [Ruby Feature#21781] Add `fetch_values` method on `ENV`

Issue #21781 has been reported by Earlopain (Earlopain _).

----------------------------------------
Feature #21781: Add `fetch_values` method on `ENV`
https://bugs.ruby-lang.org/issues/21781

* Author: Earlopain (Earlopain _)
* Status: Open
----------------------------------------
In https://bugs.ruby-lang.org/issues/10017, `fetch_values` was introduced for `Hash`. `ENV` is hash-like but is missing the method. Here are the differences between hash and env right now:

```rb
irb(main):006> Hash.instance_methods - ENV.methods
=> 
[:merge,
 :compare_by_identity,
 :compare_by_identity?,
 :>=,
 :deconstruct_keys,
 :dig,
 :<=,
 :>,
 :<,
 :to_proc,
 :flatten,
 :compact!,
 :default=,
 :default_proc,
 :default_proc=,
 :default,
 :transform_keys,
 :transform_keys!,
 :transform_values!,
 :fetch_values,
 :transform_values]
```

`flatten`/`dig` among others make no sense for `ENV`. Some I don't see why they are not present but I won't argue for them since I have no use-case.

Here is code I wanted to write:

```rb
# Get many env variables and crash if one is missing
user, pass, year, target_dir = ENV.fetch_values("USER", "PASS", "YEAR", "TARGET_DIR")
```

For now I am simply adding `to_h` and all is good. But should I have to? Ignoring a small amount of methods, ENV is very close to a hash already.



-- 
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