From ade7e83b0333f322a4fe8c1930342c42af8a0172 Mon Sep 17 00:00:00 2001
From: vabatta <2137077+vabatta@users.noreply.github.com>
Date: Mon, 9 Mar 2026 00:22:01 +0100
Subject: [PATCH] fix(cz): enforce blank line between subject and body per spec

The Conventional Commits spec requires: "body MUST begin one blank
line after the description." Single-line messages (no body) are
unaffected.
---
 dist/cz/bin/cz          |  6 +++++
 scripts/cz/cmd_lint.sh  |  8 +++++++
 scripts/cz/main_spec.sh | 50 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/dist/cz/bin/cz b/dist/cz/bin/cz
index 554157e..2a4b446 100755
--- a/dist/cz/bin/cz
+++ b/dist/cz/bin/cz
@@ -692,6 +692,12 @@ cmd_lint() {
 		return 1
 	}
 
+	local rest="${message#*$'\n'}"
+	[[ "$rest" != "$message" && "${rest%%$'\n'*}" != "" ]] && {
+		_err "body MUST begin one blank line after the description"
+		return 1
+	}
+
 	if [[ "${BREAKING_FOOTER-unset}" == "1" ]]; then
 		breaking_footer=true
 	elif [[ "${BREAKING_FOOTER-unset}" == "" ]]; then
diff --git a/scripts/cz/cmd_lint.sh b/scripts/cz/cmd_lint.sh
index 3a4a485..677dd46 100644
--- a/scripts/cz/cmd_lint.sh
+++ b/scripts/cz/cmd_lint.sh
@@ -75,6 +75,14 @@ cmd_lint() {
 		return 1
 	}
 
+	# Validate blank line after subject when body/footer present
+	# Spec: "body MUST begin one blank line after the description"
+	local rest="${message#*$'\n'}"
+	[[ "$rest" != "$message" && "${rest%%$'\n'*}" != "" ]] && {
+		_err "body MUST begin one blank line after the description"
+		return 1
+	}
+
 	# Determine breaking-footer mode
 	if [[ "${BREAKING_FOOTER-unset}" == "1" ]]; then
 		breaking_footer=true
diff --git a/scripts/cz/main_spec.sh b/scripts/cz/main_spec.sh
index c23e62d..fcc57b0 100644
--- a/scripts/cz/main_spec.sh
+++ b/scripts/cz/main_spec.sh
@@ -97,6 +97,56 @@ Describe 'cz'
 			End
 		End
 
+		#───────────────────────────────────────────────────────────
+		# Body blank line (spec: body MUST begin one blank line)
+		#───────────────────────────────────────────────────────────
+		Describe 'body blank line'
+			It 'accepts single-line message (no body)'
+				Data "docs: correct spelling of CHANGELOG"
+				When run script "$BIN" lint
+				The status should be success
+			End
+
+			It 'accepts message with blank line before body'
+				Data
+					#|fix: prevent racing of requests
+					#|
+					#|Introduce a request id and a reference to latest request. Dismiss
+					#|incoming responses other than from latest request.
+				End
+				When run script "$BIN" lint
+				The status should be success
+			End
+
+			It 'rejects body without blank line separator'
+				Data
+					#|fix: prevent racing of requests
+					#|Introduce a request id and a reference to latest request.
+				End
+				When run script "$BIN" lint
+				The status should be failure
+				The stderr should include "body MUST begin one blank line after the description"
+			End
+
+			It 'rejects footer without blank line separator'
+				Data
+					#|feat: allow provided config object to extend other configs
+					#|BREAKING CHANGE: `extends` key in config file is now used for extending other config files
+				End
+				When run script "$BIN" lint
+				The status should be failure
+				The stderr should include "body MUST begin one blank line after the description"
+			End
+
+			It 'accepts message with only a trailing newline'
+				Data
+					#|docs: correct spelling of CHANGELOG
+				End
+				When run script "$BIN" lint
+				The status should be success
+			End
+		End
+
 		#───────────────────────────────────────────────────────────
 		# Invalid conventional commits
 		#───────────────────────────────────────────────────────────