fix(spec): shell completion mocks across bash, zsh, and fish

.github/workflows/test.yml

@@ -13,8 +13,6 @@ on:
       - mkdocs.yml
       - LICENSE
   pull_request:
-    branches:
-      - main
 
 permissions:
   contents: read

src/tabular/shell.cr

@@ -66,8 +66,13 @@ module Tabular(T)
         end
 
         buffer
-      rescue IO::Error
-        raise Exception.new stderr.gets_to_end
+      rescue err : IO::Error
+        # Surface anything the simulator wrote to stderr — and if it stayed
+        # silent, fall back to the original IO::Error so the failure isn't
+        # reported as a bare "Error:" with no detail.
+        diag = stderr.gets_to_end rescue ""
+        diag = "#{err.class}: #{err.message} (no stderr captured)" if diag.empty?
+        raise Exception.new "[#{self} simulator] #{diag}"
       end
     end
 

src/tabular/shell/bash.ecr

@@ -1,10 +1,38 @@
+# History expansion turns the `!` in `_filedir`'s xspec into a syntax error and
+# leaves descriptions unformatted when `COLUMNS` is unset, so harden both up
+# front before any completion machinery is loaded.
+set +H
+export COLUMNS="${COLUMNS:-200}"
+
 <% {% if flag?(:darwin) %} -%>
 init="/opt/homebrew/etc/profile.d/bash_completion.sh"
 <% {% end %} -%>
 <% {% if flag?(:linux) %} -%>
 init="/etc/profile.d/bash_completion.sh"
 <%- {% end %} -%>
 [[ -f "${init}" ]] && . "${init}"
+
+# Patch `_filedir` so an empty `cur` still expands extension filters. Stock
+# bash-completion routes empty cur through `_quote_readline_by_ref`, which
+# yields the literal `''` and then matches no files; real bash papers over
+# this with `complete -o default`, but the mock has no shell to fall back to.
+if declare -F _filedir >/dev/null 2>&1; then
+	eval "__tabular_orig_filedir() $(declare -f _filedir | tail -n +2)"
+	_filedir() {
+		if [[ -z ${cur-} && -n ${1-} && ${1-} != "-d" ]]; then
+			local __xspec="!*.@(${1}|${1^^})"
+			local __reset
+			__reset=$(shopt -po noglob)
+			set -o noglob
+			COMPREPLY+=( $(compgen -f -X "$__xspec" -o plusdirs -- "") )
+			$__reset
+			(( ${#COMPREPLY[@]} > 0 )) && compopt -o filenames 2>/dev/null
+			return 0
+		fi
+		__tabular_orig_filedir "$@"
+	}
+fi
+
 <% completers.each do |comp| -%>
 eval "$(<%= comp %> completion <%= bin %>)"
 <% end %>

src/tabular/shell/fish.ecr

@@ -1,7 +1,16 @@
 <% completers.each do |comp| -%>
 <%= comp %> completion <%= bin %> | source
 <% end %>
-while read -l LINE < /dev/stdin
+# fish 3.x's `read` builtin closes stdin after the first line when invoked
+# from a `-c` script with a piped stdin. The historical workaround was
+# `read -l LINE < /dev/stdin`, but on macOS BSD that opens a fresh fd via
+# /dev/fd/0 which EOFs on the second iteration and silently kills the loop.
+# `head -n 1` sidesteps the buffering quirk on both platforms; relying on
+# the simulator being synchronous (one line in / one response out) keeps
+# its read-ahead from eating subsequent lines.
+while true
+	set -l LINE (head -n 1)
+	test -z "$LINE"; and break
 	complete -C "<%= prog %> $LINE"
 	printf '\0'
 end

src/tabular/shell/zsh.ecr

@@ -1,59 +1,92 @@
 # SEE: https://unix.stackexchange.com/questions/668618/how-to-write-automated-tests-for-zsh-completion/668827#668827
+#
+# Background:
+#   The Stack Exchange recipe runs `vared -c tmp` inside `zpty {,}fn`, but on
+#   glibc-based zsh 5.9 builds (Ubuntu 24.04, Debian sid, recent Homebrew)
+#   that combination corrupts the heap and the pty emits `free(): invalid
+#   pointer` instead of any completions. Spawning a fresh interactive
+#   `zsh -fi -c 'source <file>'` inside the zpty gives ZLE its own session and
+#   sidesteps the crash. We also avoid an EXIT trap on the outer shell — zpty
+#   propagates inherited traps to the child, so an outer cleanup trap would
+#   delete the source file out from under the next iteration.
+#
+#   The inner shell prints a READY sentinel right before `vared` activates, so
+#   the outer shell waits for it before sending input. Without that handshake,
+#   macOS pty buffering races with `zpty -w` and the TAB lands before ZLE has
+#   bound it, hanging on `vared` forever.
 autoload -U compinit
-compinit
+compinit -u
 
 <% completers.each do |comp| -%>
 eval "$(<%= comp %> completion <%= bin %>)"
+<% end %>
+
+# `mktemp -p` is GNU-only; BSD `mktemp` (macOS) treats `-p` as the prefix flag.
+# Use an explicit path under TMPDIR (or /tmp) instead, which both honor.
+INNER="${TMPDIR:-/tmp}/tabular_<%= pty %>.$$"
+: > "${INNER}" || exit 1
+{
+	print -r -- 'autoload -U compinit'
+	print -r -- 'compinit -u'
+<% completers.each do |comp| -%>
+	print -r -- 'eval "$(<%= comp %> completion <%= bin %>)"'
 <% end -%>
+	print -r -- 'D_OPN=$'\''\C-B'\'
+	print -r -- 'D_CLS=$'\''\C-C'\'
+	print -r -- 'D_RDY=$'\''\C-E'\'
+	print -r -- 'zstyle ":completion:*" max-matches-width 10'
+	print -r -- 'zstyle ":completion:*" list-colors ""'
+	print -r -- 'zle -C {,,}complete-word'
+	print -r -- 'complete-word () {'
+	print -r -- '  unset "compstate[vared]"'
+	print -r -- '  compstate[insert]=menu'
+	print -r -- '  compadd -x "${D_OPN}"'
+	print -r -- '  _main_complete "$@"'
+	print -r -- '  if [ -n "$compstate[unambiguous]" ] && [ "$compstate[nmatches]" = "1" ]; then'
+	print -r -- '    result=${compstate[unambiguous]/#$BASH_REMATCH}'
+	print -r -- '    echo -e "${D_OPN}\n${result}\n${D_CLS}"'
+	print -r -- '  fi'
+	print -r -- '  compadd -J -last- -x "${D_CLS}"'
+	print -r -- '  exit'
+	print -r -- '}'
+	print -r -- 'bindkey "^I" complete-word'
+	# Trailing newline is required: pty stdout is line-buffered, so a bare
+	# `\C-E` would sit in the inner shell's buffer and the outer would block.
+	print -r -- 'print -- "${D_RDY}"'
+	print -r -- 'vared -c tmp'
+} > "${INNER}"
+
+D_OPN=$'\C-B'
+D_CLS=$'\C-C'
+D_RDY=$'\C-E'
+
+zmodload zsh/zpty
+
+while read -r -t10 -A ARGS; do
+	zpty <%= pty %> "zsh -fi -c 'source ${INNER}'"
 
-compmock () {
-  export D_OPN=$'\C-B'
-  export D_CLS=$'\C-C'
-
-  <%= pty %> () {
-    zstyle ':completion:*' max-matches-width 10 # Ensure alt-names on separate rows
-    zstyle ':completion:*' list-colors '' # Disable colouring
-
-    # Bind a custom widget to TAB.
-    bindkey '^I' complete-word
-    zle -C {,,}complete-word
-    complete-word () {
-      unset 'compstate[vared]' # Disguise a "normal" command-line
-      compstate[insert]=menu # Ensure menu is always displayed
-      compadd -x "${D_OPN}" # Open delimiter
-      _main_complete "$@" # Run completion
-      # Intercept unambiguous match
-      if [ -n "$compstate[unambiguous]" ] && [ "$compstate[nmatches]" = '1' ]; then
-        result=${compstate[unambiguous]/#$BASH_REMATCH}
-        echo -e "${D_OPN}\n${result}\n${D_CLS}"
-      fi
-      compadd -J -last- -x "${D_CLS}" # close delimiter
-      exit
-    }
-
-    vared -c tmp # Start line editor
-  }
-
-  zmodload zsh/zpty  # Load the pseudo terminal module.
-	trap 'zpty -d' ABRT EXIT HUP INT QUIT TERM  # Delete the pty.
-
-	while read -r -t10 -A ARGS; do
-		zpty {,}<%= pty %>   # Create a new pty and run our function in it.
-		zpty -w -n <%= pty %> "$1 $ARGS[*]"$'\t'  # Simulate a command being typed and tabbed.
-
-		# Capture terminal output
-		PTY_LINES=()
-		while zpty -r <%= pty %> REPLY; do
-			[[ "${REPLY}" =~ "${D_CLS}" ]] && break
-			[[ "${REPLY}" =~ "${D_OPN}" ]] \
-				&& PTY_LINES=() \
-				|| PTY_LINES+=("${REPLY%%$'\n'}")
-		done
-
-		print -nrC1 -- "${PTY_LINES[@]}" | sed -r -e 's/\x1b\[[0-9;]*m?//g' -e 's/\r//g' -e 's/ *$//g'
-    print -n -- $'\C-@'
-    zpty -d <%= pty %>
+	# Wait until the inner shell has bound TAB and is parked in `vared`.
+	while zpty -r <%= pty %> REPLY; do
+		[[ "${REPLY}" == *"${D_RDY}"* ]] && break
 	done
-}
 
-compmock <%= prog %>
+	zpty -w -n <%= pty %> "<%= prog %> ${ARGS[*]}"$'\t'
+
+	PTY_LINES=()
+	while zpty -r <%= pty %> REPLY; do
+		[[ "${REPLY}" == *"${D_CLS}"* ]] && break
+		if [[ "${REPLY}" == *"${D_OPN}"* ]]; then
+			REPLY="${REPLY##*${D_OPN}}"
+			PTY_LINES=()
+		fi
+		PTY_LINES+=("${REPLY%%$'\n'}")
+	done
+
+	print -nrC1 -- "${PTY_LINES[@]}" \
+		| sed -r -e 's/\x1b\[[0-9;]*m?//g' -e 's/\r//g' -e 's/ *$//g' \
+		| sed '/^$/d'
+	print -n -- $'\C-@'
+	zpty -d <%= pty %>
+done
+
+rm -f "${INNER}"