Add tox checker for lengths of new lines only

- Still non-voting, but useful.

Change-Id: Idd6f345f0f14fdbc237ff66f5e010801ea08dc5b
Signed-off-by: Vratko Polak <vrpolak@cisco.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/resources/libraries/bash/entry/check/new_line.sh b/resources/libraries/bash/entry/check/new_line.sh
new file mode 100644
index 0000000000..49c3d65815
--- /dev/null
+++ b/resources/libraries/bash/entry/check/new_line.sh
@@ -0,0 +1,51 @@
+# Copyright (c) 2019 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -exuo pipefail
+
+# This file should be executed from tox, as the assumend working directory
+# is different from where this file is located.
+# This file does not have executable flag nor shebang,
+# to dissuade non-tox callers.
+
+# This script runs a grep-based command and fails if it detects any lines
+# edited or added since HEAD~ and longer than 80 characters.
+# The grep output stored to new_lines.log (overwriting).
+
+# See lines.log to locate where the lines are.
+
+# "set -eu" handles failures from the following two lines.
+BASH_CHECKS_DIR="$(dirname $(readlink -e "${BASH_SOURCE[0]}"))"
+BASH_FUNCTION_DIR="$(readlink -e "${BASH_CHECKS_DIR}/../../function")"
+source "${BASH_FUNCTION_DIR}/common.sh" || {
+    echo "Source failed." >&2
+    exit 1
+}
+
+# Greps do "fail" on zero line output, we need to ignore that in the final grep.
+piped_command="set -exuo pipefail && git diff -U0 HEAD~ | grep '^\+' | "
+piped_command+="cut -c2- | grep -v '^\+\+ ' | { grep '.\{81\}' || true; } | "
+piped_command+="tee 'new_lines.log' | wc -l"
+lines="$(bash -c "${piped_command}")" || die
+if [ "${lines}" != "0" ]; then
+    # TODO: Decide which text goes to stdout and which to stderr.
+    warn "Long lines detected: ${lines}"
+    # TODO: Disable when output size does more harm than good.
+    cat "new_lines.log" >&2
+    warn
+    warn "New line length checker: FAIL"
+    exit 1
+fi
+
+warn
+warn "New line length checker: PASS"