Create library so the tools can use similar functionality

.github/workflows/test.yml

@@ -0,0 +1,12 @@
+name: "Test"
+
+on:
+  pull_request:
+
+jobs:
+  shell-scripts:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: luizm/action-sh-checker@883217215b11c1fabbf00eb1a9a041f62d74c744
+        env: { SHFMT_OPTS: -i 2 -d }

.shellcheckrc

@@ -0,0 +1,4 @@
+external-sources=true
+check-sourced=true
+source-path=lib
+enable=avoid-nullary-conditions,check-unassigned-uppercase,deprecate-which,quote-safe-variables,useless-use-of-cat

lib/ci-tools.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+################################################################################
+# Because GitHub runners don't set these:
+export LANG=en_US.UTF-8
+export LC_ALL=$LANG
+export LC_COLLATE=$LANG
+
+################################################################################
+# Strip whitespace and delete blank lines from STDIN to STDOUT.
+function strip_space() {
+  sed -E \
+    -e 's/^[[:space:]]+//' \
+    -e 's/[[:space:]]+$//' \
+    -e 's/[[:space:]]+/ /' \
+    -e '/^[[:space:]]*$/d'
+}
+
+################################################################################
+# Resolve a `git` commit name given on the command line.
+#
+# When a repository is cloned in a GitHub action the main branch isn't
+# available directly, even though `$GITHUB_BASE_REF` references it.
+# So we need to fully qualify any symbolic revision name we are given.
+function resolve_git_commit() {
+  local name=$1
+  local commit
+
+  local possible=(
+    "$name"
+    "origin/$name"
+    "remotes/origin/$name"
+  )
+
+  for rev in "${possible[@]}"; do
+    commit=$(git rev-parse --verify --quiet "$rev" || :)
+
+    if [ -n "$commit" ]; then
+      break
+    fi
+  done
+
+  if [ -z "$commit" ]; then
+    echo >&2 "ERROR: invalid revision: $name"
+    exit 1
+  fi
+
+  echo "$commit"
+}

scripts/authors.sh

@@ -5,10 +5,8 @@ set -eu
 set -o pipefail
 
 ################################################################################
-# Because GitHub runners don't set these:
-export LANG=en_US.UTF-8
-export LC_ALL=$LANG
-export LC_COLLATE=$LANG
+script_dir=$(realpath "$(dirname "$0")")
+source "$script_dir/../lib/ci-tools.sh"
 
 ################################################################################
 option_from="HEAD^"
@@ -32,48 +30,6 @@ NOTE: Must be exeucted from within a git repository.
 EOF
 }
 
-################################################################################
-# Strip whitespace and delete blank lines from STDIN to STDOUT.
-function strip_space() {
-  sed -E \
-    -e 's/^[[:space:]]+//' \
-    -e 's/[[:space:]]+$//' \
-    -e 's/[[:space:]]+/ /' \
-    -e '/^[[:space:]]*$/d'
-}
-
-################################################################################
-# Resolve a `git` commit name given on the command line.
-#
-# When a repository is cloned in a GitHub action the main branch isn't
-# available directly, even though `$GITHUB_BASE_REF` references it.
-# So we need to fully qualify any symbolic revision name we are given.
-function resolve_git_commit() {
-  local name=$1
-  local commit
-
-  local possible=(
-    "$name"
-    "origin/$name"
-    "remotes/origin/$name"
-  )
-
-  for rev in "${possible[@]}"; do
-    commit=$(git rev-parse --verify --quiet "$rev" || :)
-
-    if [ -n "$commit" ]; then
-      break
-    fi
-  done
-
-  if [ -z "$commit" ]; then
-    echo >&2 "ERROR: invalid revision: $name"
-    exit 1
-  fi
-
-  echo "$commit"
-}
-
 ################################################################################
 # Ask `git` for a list of authors.
 function authors_from_git() {

scripts/check-tool-handler.sh

@@ -4,6 +4,10 @@
 set -eu
 set -o pipefail
 
+################################################################################
+script_dir=$(realpath "$(dirname "$0")")
+source "$script_dir/../lib/ci-tools.sh"
+
 ################################################################################
 declare -A topp_exceptions=(
   ["FeatureLinkerBase.cpp"]=1
@@ -60,7 +64,7 @@ function topp_files_in_map() {
 
     if [ "${topp_exceptions[$base]:-0}" -ne 1 ] && ! is_in_tools_map_cpp "$base"; then
       echo >&2 "ERROR: $base is not listed in $option_tool_handler_cpp"
-      exit 1
+      exit 100
     fi
   done < <(find "$option_topp_dir" -type f -name '*.cpp' -print0)
 }
@@ -121,8 +125,8 @@ function main() {
 
   if [ $# -gt 0 ]; then
     if [ $# -eq 2 ]; then
-      option_from=$1
-      option_to=$2
+      option_from=$(resolve_git_commit "$1")
+      option_to=$(resolve_git_commit "$2")
     else
       echo >&2 "ERROR: provide exactly two commits"
       exit 1