create-new-feature.sh: xargs-based trimming breaks descriptions containing apostrophes or quotes

[phantom-suzuki]

Summary

.specify/scripts/bash/create-new-feature.sh (as shipped in spec-kit v0.8.0 templates, observed via specify init) uses xargs to strip surrounding whitespace from the positional FEATURE_DESCRIPTION argument:

# around line 87
FEATURE_DESCRIPTION=$(echo "$FEATURE_DESCRIPTION" | xargs)

Because xargs re-parses its stdin as shell-like tokens, any input containing a single quote ('), double quote ("), or backslash (\) aborts immediately with:

xargs: unterminated quote

and the script exits before creating the branch or spec directory.

Reproduction

# from a spec-kit initialized project
bash .specify/scripts/bash/create-new-feature.sh --dry-run "Add user's profile page"
# → xargs: unterminated quote

Natural-language descriptions frequently include apostrophes (user's, can't, etc.), so this is easy to trigger in normal usage.

Expected

The trim step should only strip leading/trailing whitespace, not re-interpret the input as shell tokens.

Suggested fix

Replace the xargs call with a quote-safe whitespace trim. A few options:

# bash parameter expansion (no subshell)
FEATURE_DESCRIPTION="${FEATURE_DESCRIPTION#"${FEATURE_DESCRIPTION%%[![:space:]]*}"}"
FEATURE_DESCRIPTION="${FEATURE_DESCRIPTION%"${FEATURE_DESCRIPTION##*[![:space:]]}"}"

# or: sed-based trim
FEATURE_DESCRIPTION=$(echo "$FEATURE_DESCRIPTION" | sed -E 's/^[[:space:]]+|[[:space:]]+$//g')

# or: awk-based trim
FEATURE_DESCRIPTION=$(echo "$FEATURE_DESCRIPTION" | awk '{$1=$1;print}')

All three preserve input content verbatim regardless of quoting.

Environment

• spec-kit template version: v0.8.0
• specify-cli version: 0.8.1.dev0
• Shell: bash / zsh (both reproduce)
• OS: macOS (should also reproduce on Linux since xargs behavior is POSIX-ish)

Context

Found during a scaffold migration from v0.0.22 → v0.8.0 (older template layout). The regression was flagged by an automated code review on the downstream migration PR.