command-not-found-init: match fish init behavior to *sh

[gromgit]

Addresses #20740.

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[ZhongRuoyu]

Will this break existing usage? Or can this be done in a way that it doesn't?

https://github.com/search?q=%22brew%20command-not-found-init%22%20lang%3Afish&type=code

I understand that this is fixing an inconsistency, but it seems like this special logic for Fish (as compared to Bash and Zsh) has lived since Fish support was added (Homebrew/homebrew-command-not-found@ebfe42a). I'm not a Fish user so I can't tell why it was done that way though.

[ZhongRuoyu]

How about this: given that source (brew command-not-found-init) in Fish will print out the following after this change:

$ source (brew command-not-found-init)
source: Error encountered while sourcing file ''# License: MIT'':
source: No such file or directory

We update the first line of handler.fish as follows:

--- a/Library/Homebrew/command-not-found/handler.fish
+++ b/Library/Homebrew/command-not-found/handler.fish
@@ -1,3 +1,4 @@
+# If see this error, please update your config.fish following https://docs.brew.sh/Command-Not-Found
 # License: MIT
 # The license text can be found in Library/Homebrew/command-not-found/LICENSE
 

... and update the documentation accordingly (or not, because the documented way still works), so that people relying on the existing behaviour can migrate without confusion:

$ source (brew command-not-found-init)
source: Error encountered while sourcing file ''# If see this error, please update your config.fish following https://docs.brew.sh/Command-Not-Found'':
source: No such file or directory

[gromgit]

Thanks for the suggestion, @ZhongRuoyu! Users of the old formulation will now see this instead:

> . (brew command-not-found-init)
.: Error encountered while sourcing file ''# See https://docs.brew.sh/Command-Not-Found for current setup instructions'':
.: No such file or directory

[ZhongRuoyu]

Thanks @gromgit!

[MikeMcQuaid]

Looks good, thanks!