From 4f357445053352ff38d152fd8f291e06a16fdc64 Mon Sep 17 00:00:00 2001
From: Carter McKinnon <mckdev@amazon.com>
Date: Wed, 18 Oct 2023 08:24:47 -0700
Subject: [PATCH] Add fmt/lint for trailing spaces

---
 Makefile                     |  2 ++
 hack/fmt-trailing-spaces.sh  | 21 +++++++++++++++++++++
 hack/lint-trailing-spaces.sh |  4 ++++
 3 files changed, 27 insertions(+)
 create mode 100755 hack/fmt-trailing-spaces.sh
 create mode 100755 hack/lint-trailing-spaces.sh

diff --git a/Makefile b/Makefile
index f7c64c618..40d952791 100644
--- a/Makefile
+++ b/Makefile
@@ -79,6 +79,7 @@ endif
 .PHONY: fmt
 fmt: ## Format the source files
 	$(SHFMT_COMMAND) $(SHFMT_FLAGS) --write $(MAKEFILE_DIR)
+	hack/fmt-trailing-spaces.sh
 
 SHELLCHECK_COMMAND := $(shell which shellcheck)
 ifeq (, $(SHELLCHECK_COMMAND))
@@ -96,6 +97,7 @@ transform-al2-to-al2023:
 lint: lint-docs ## Check the source files for syntax and format issues
 	$(SHFMT_COMMAND) $(SHFMT_FLAGS) --diff $(MAKEFILE_DIR)
 	$(SHELLCHECK_COMMAND) --format gcc --severity error $(SHELL_FILES)
+	hack/lint-trailing-spaces.sh
 
 .PHONY: test
 test: ## run the test-harness
diff --git a/hack/fmt-trailing-spaces.sh b/hack/fmt-trailing-spaces.sh
new file mode 100755
index 000000000..80e7770a5
--- /dev/null
+++ b/hack/fmt-trailing-spaces.sh
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+cd $(dirname $0)/..
+
+OS=$(uname)
+for FILE in $(find . -type f -not -path "*/.git/*"); do
+  if [ "$OS" = "Darwin" ]; then
+    # macOS sed doesn't support '-i'
+    sed 's/[[:space:]]*$//g' "$FILE" > "$FILE.tmp"
+    # macOS chmod doesn't support '--reference'
+    chmod "$(stat -f "%Mp%Lp" $FILE)" "$FILE.tmp"
+    mv "$FILE.tmp" "$FILE"
+  else
+    # assume we have a sane sed
+    sed -i 's/[[:space:]]*$//g' "$FILE"
+  fi
+done
diff --git a/hack/lint-trailing-spaces.sh b/hack/lint-trailing-spaces.sh
new file mode 100755
index 000000000..60bf8802e
--- /dev/null
+++ b/hack/lint-trailing-spaces.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+cd $(dirname $0)/..
+git diff-tree --check $(git hash-object -t tree /dev/null) HEAD