fix: use fish long options for multi-character flag names

[SulimanAbdulrazzaq]

What type of PR is this?

• bug

What this PR does / why we need it:

ToFishCompletion writes the first name of a flag as -l and every other name as -s. fish reads the argument of complete -s as a group of one-character options, so an alias with more than one character is registered as several unrelated short options instead of one long option, and a one-character first name is registered as a long option.

For Name: "verbose", Aliases: []string{"loud", "v"} the generated line was -l verbose -s loud -s v. With fish 3.7.0 on the old output, complete -C 'greet --lo' returns nothing and complete -C 'greet -l' offers -ld -lo -lp -lt -lu -lv. For Name: "o", Aliases: []string{"output", "out"} the old output registered --o and the short options o, u, t, p.

The generator now uses -s for a one-character name and -l for any other name, whichever position it has in the flag's names. With the change, complete -C 'greet --lo' returns --loud and complete -C 'greet --ou' returns --out and --output.

• fish.go: choose -s or -l per name.
• testdata/expected-fish-full.fish: the fl and sub-fl aliases are now -l fl and -l sub-fl.
• fish_test.go: new TestFishCompletionShortAndLongNames.

Which issue(s) this PR fixes:

NONE

Special notes for your reviewer:

Not changed on purpose: command aliases are still not offered by the fish completion, and the bash, zsh and PowerShell scripts do not use these options. Flags whose names are all one character, or whose aliases are all one character (the existing help golden file), generate the same output as before.

Testing

make lint, make vet, make test, make test GFLAGS='--tags urfave_cli_no_template', make generate, make diffcheck and make v3diff pass in a fork run on ubuntu. The new test fails without the change and passes with it. A fork step also sources the generated script in fish 3.7.0 and runs complete -C as described above.

Release Notes

Fish completion: flag names longer than one character are now generated as long options (`-l`), and one-character names as short options (`-s`), wherever they appear in a flag's names.

[greptile-apps]

Confidence Score: 5/5

[Medium risk] Fixes fish shell completion flag formatting logic.

The PR appears safe to merge.

Summary

The PR selects fish short or long completion options by each flag name’s length rather than its position, adds a regression test, and updates the expected completion script. No actionable issues were identified.

_{Reviews (1) · Last reviewed commit: "fix: use fish long options for multi-cha..."}