installShellFiles: Add nushell support to installShellCompletion (#428168)

doc/hooks/installShellFiles.section.md

···
 completion files.
 
 By default it will autodetect the shell type from the completion file extension,
-but you may also specify it by passing one of `--bash`, `--fish`, or
-`--zsh`. These flags apply to all paths listed after them (up until another
+but you may also specify it by passing one of `--bash`, `--fish`, `--zsh`, or
+`--nushell`. These flags apply to all paths listed after them (up until another
 shell flag is given). Each path may also have a custom installation name
 provided by providing a flag `--name NAME` before the path. If this flag is not
 provided, zsh completions will be renamed automatically such that `foobar.zsh`
···
     # explicit behavior
     installShellCompletion --bash --name foobar.bash share/completions.bash
     installShellCompletion --fish --name foobar.fish share/completions.fish
+    installShellCompletion --nushell --name foobar share/completions.nu
     installShellCompletion --zsh --name _foobar share/completions.zsh
     # implicit behavior
-    installShellCompletion share/completions/foobar.{bash,fish,zsh}
+    installShellCompletion share/completions/foobar.{bash,fish,zsh,nu}
   '';
 }
 ```
···
     installShellCompletion --cmd foobar \
       --bash <($out/bin/foobar --bash-completion) \
       --fish <($out/bin/foobar --fish-completion) \
+      --nushell <($out/bin/foobar --nushell-completion) \
       --zsh <($out/bin/foobar --zsh-completion)
   '';
 }

doc/release-notes/rl-2511.section.md

···
 
 - [`homebox` 0.20.0](https://github.com/sysadminsmedia/homebox/releases/tag/v0.20.0) changed how assets are stored and hashed. It is recommended to back up your database before this update.
 
+- `installShellCompletion`: now supports Nushell completion files
+
 - New hardening flags, `strictflexarrays1` and `strictflexarrays3` were made available, corresponding to the gcc/clang options `-fstrict-flex-arrays=1` and `-fstrict-flex-arrays=3` respectively.
 
 - `gramps` has been updated to 6.0.0

pkgs/by-name/in/installShellFiles/setup-hook.sh

···
 # installShellCompletion [--cmd <name>] ([--bash|--fish|--zsh] [--name <name>] <path>)...
 #
 # Each path is installed into the appropriate directory for shell completions for the given shell.
-# If one of `--bash`, `--fish`, or `--zsh` is given the path is assumed to belong to that shell.
-# Otherwise the file extension will be examined to pick a shell. If the shell is unknown a warning
-# will be logged and the command will return a non-zero status code after processing any remaining
-# paths. Any of the shell flags will affect all subsequent paths (unless another shell flag is
-# given).
+# If one of `--bash`, `--fish`, `--zsh`, or `--nushell` is given the path is assumed to belong to
+# that shell. Otherwise the file extension will be examined to pick a shell. If the shell is
+# unknown a warning will be logged and the command will return a non-zero status code after
+# processing any remaining paths. Any of the shell flags will affect all subsequent paths (unless
+# another shell flag is given).
 #
 # If the shell completion needs to be renamed before installing the optional `--name <name>` flag
 # may be given. Any name provided with this flag only applies to the next path.
···
 #
 #   installShellCompletion --bash --name foobar.bash share/completions.bash
 #   installShellCompletion --fish --name foobar.fish share/completions.fish
+#   installShellCompletion --nushell --name foobar share/completions.nu
 #   installShellCompletion --zsh --name _foobar share/completions.zsh
 #
 # Or to use shell newline escaping to split a single invocation across multiple lines:
···
 #   installShellCompletion --cmd foobar \
 #     --bash <($out/bin/foobar --bash-completion) \
 #     --fish <($out/bin/foobar --fish-completion) \
+#     --nushell <($out/bin/foobar --nushell-completion)
 #     --zsh <($out/bin/foobar --zsh-completion)
 #
 # If any argument is `--` the remaining arguments will be treated as paths.
···
         # Parse arguments
         if (( parseArgs )); then
             case "$arg" in
-            --bash|--fish|--zsh)
+            --bash|--fish|--zsh|--nushell)
                 shell=${arg#--}
                 continue;;
             --name)
···
         elif [[ -p "$arg" ]]; then
             # this is a named fd or fifo
             if [[ -z "$curShell" ]]; then
-                nixErrorLog "${FUNCNAME[0]}: named pipe requires one of --bash, --fish, or --zsh"
+                nixErrorLog "${FUNCNAME[0]}: named pipe requires one of --bash, --fish, --zsh, or --nushell"
                 return 1
             elif [[ -z "$name" && -z "$cmdname" ]]; then
                 nixErrorLog "${FUNCNAME[0]}: named pipe requires one of --cmd or --name"
···
                 case "$argbase" in
                 ?*.bash) curShell=bash;;
                 ?*.fish) curShell=fish;;
+                ?*.nu) curShell=nushell;;
                 ?*.zsh) curShell=zsh;;
                 *)
                     if [[ "$argbase" = _* && "$argbase" != *.* ]]; then
···
         elif [[ -n "$cmdname" ]]; then
             case "$curShell" in
             bash|fish) outName=$cmdname.$curShell;;
+            nushell) outName=$cmdname.nu;;
             zsh) outName=_$cmdname;;
             *)
                 # Our list of shells is out of sync with the flags we accept or extensions we detect.
···
         case "$curShell" in
         bash) sharePath=bash-completion/completions;;
         fish) sharePath=fish/vendor_completions.d;;
+        nushell) sharePath=nushell/vendor/autoload;;
         zsh)
             sharePath=zsh/site-functions
             # only apply automatic renaming if we didn't have a manual rename

pkgs/by-name/in/installShellFiles/tests/install-completion-cmd.nix

···
     echo bar > bar.zsh
     echo baz > baz.fish
     echo qux > qux.fish
+    echo buzz > buzz.nu
 
-    installShellCompletion --cmd foobar --bash foo.bash --zsh bar.zsh --fish baz.fish --name qux qux.fish
+    installShellCompletion \
+      --cmd foobar --bash foo.bash \
+      --zsh bar.zsh \
+      --fish baz.fish --name qux qux.fish \
+      --nushell --cmd buzzbar buzz.nu
 
     cmp foo.bash $out/share/bash-completion/completions/foobar.bash
     cmp bar.zsh $out/share/zsh/site-functions/_foobar
     cmp baz.fish $out/share/fish/vendor_completions.d/foobar.fish
     cmp qux.fish $out/share/fish/vendor_completions.d/qux
+    cmp buzz.nu $out/share/nushell/vendor/autoload/buzzbar.nu
   ''

pkgs/by-name/in/installShellFiles/tests/install-completion-fifo.nix

···
     installShellCompletion \
       --bash --name foo.bash <(echo foo) \
       --zsh --name _foo <(echo bar) \
-      --fish --name foo.fish <(echo baz)
+      --fish --name foo.fish <(echo baz) \
+      --nushell --name foo.nu <(echo bucks)
 
     [[ $(<$out/share/bash-completion/completions/foo.bash) == foo ]] || { echo "foo.bash comparison failed"; exit 1; }
     [[ $(<$out/share/zsh/site-functions/_foo) == bar ]] || { echo "_foo comparison failed"; exit 1; }
     [[ $(<$out/share/fish/vendor_completions.d/foo.fish) == baz ]] || { echo "foo.fish comparison failed"; exit 1; }
+    [[ $(<$out/share/nushell/vendor/autoload/foo.nu) == bucks ]] || { echo "foo.nu comparison failed"; exit 1; }
   ''

pkgs/by-name/in/installShellFiles/tests/install-completion-inference.nix

···
     echo foo > foo.bash
     echo bar > bar.zsh
     echo baz > baz.fish
+    echo buzz > buzz.nu
 
-    installShellCompletion foo.bash bar.zsh baz.fish
+    installShellCompletion foo.bash bar.zsh baz.fish buzz.nu
 
     cmp foo.bash $out/share/bash-completion/completions/foo.bash
     cmp bar.zsh $out/share/zsh/site-functions/_bar
     cmp baz.fish $out/share/fish/vendor_completions.d/baz.fish
+    cmp buzz.nu $out/share/nushell/vendor/autoload/buzz.nu
   ''

pkgs/by-name/in/installShellFiles/tests/install-completion-name.nix

···
     echo foo > foo
     echo bar > bar
     echo baz > baz
+    echo bucks > bucks
 
-    installShellCompletion --bash --name foobar.bash foo --zsh --name _foobar bar --fish baz
+    installShellCompletion \
+      --bash --name foobar.bash foo \
+      --zsh --name _foobar bar \
+      --fish baz \
+      --nushell --name foobar.nu bucks
 
     cmp foo $out/share/bash-completion/completions/foobar.bash
     cmp bar $out/share/zsh/site-functions/_foobar
     cmp baz $out/share/fish/vendor_completions.d/baz
+    cmp bucks $out/share/nushell/vendor/autoload/foobar.nu
   ''

pkgs/by-name/in/installShellFiles/tests/install-completion.nix

···
     echo baz > baz
     echo qux > qux.zsh
     echo quux > quux
+    echo quokka > quokka
 
-    installShellCompletion --bash foo bar --zsh baz qux.zsh --fish quux
+    installShellCompletion \
+      --bash foo bar \
+      --zsh baz qux.zsh \
+      --fish quux \
+      --nushell quokka
 
     cmp foo $out/share/bash-completion/completions/foo
     cmp bar $out/share/bash-completion/completions/bar
     cmp baz $out/share/zsh/site-functions/_baz
     cmp qux.zsh $out/share/zsh/site-functions/_qux
     cmp quux $out/share/fish/vendor_completions.d/quux
+    cmp quokka $out/share/nushell/vendor/autoload/quokka
   ''