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Add GitHub Action to check trailing whitespace on PRs #4

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Add GitHub Action to check trailing whitespace on PRs #4

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4ed2f8c
Initial plan
Copilot Nov 14, 2025
6766ff1
Add GitHub Action for trailing whitespace check on PRs
Copilot Nov 14, 2025
3090f44
Add explicit permissions to trailing whitespace check workflow
Copilot Nov 14, 2025
6f4e1f0
Simplify PATTERNS and add demo files with trailing whitespace
Copilot Nov 14, 2025
5d5bda0
Remove demo files with trailing whitespace
Copilot Nov 14, 2025
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82 changes: 82 additions & 0 deletions .github/workflows/trailing-whitespace-check.yml
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Original file line number Diff line number Diff line change
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name: Trailing Whitespace Check

on:
pull_request:
types: [opened, synchronize, reopened]

jobs:
check-trailing-whitespace:
runs-on: ubuntu-latest
permissions:
contents: read

steps:
- name: Checkout code
uses: actions/checkout@v4
with:
fetch-depth: 0

- name: Check for trailing whitespace
run: |
echo "Checking for trailing whitespace in changed files..."

# Get the base branch
BASE_SHA="${{ github.event.pull_request.base.sha }}"
HEAD_SHA="${{ github.event.pull_request.head.sha }}"

# Get list of changed files (excluding deleted files)
CHANGED_FILES=$(git diff --name-only --diff-filter=d "$BASE_SHA" "$HEAD_SHA")

if [ -z "$CHANGED_FILES" ]; then
echo "No files to check."
exit 0
fi

# File patterns to check (text files)
PATTERNS="\.cs$|\.csproj$|\.sln$|\.ts$|\.html$|\.css$|\.scss$"

# Directories and file patterns to exclude
EXCLUDE_PATTERNS="(^|\/)(\.|node_modules|bin|obj|artifacts|packages|\.vs|\.nuke\/temp)($|\/)"

ERRORS_FOUND=0
TEMP_FILE=$(mktemp)

while IFS= read -r file; do
# Skip if file doesn't exist (shouldn't happen with --diff-filter=d, but just in case)
if [ ! -f "$file" ]; then
continue
fi

# Check if file matches patterns to check
if ! echo "$file" | grep -qE "$PATTERNS"; then
continue
fi

# Check if file should be excluded
if echo "$file" | grep -qE "$EXCLUDE_PATTERNS"; then
continue
fi

# Check for trailing whitespace
if grep -n '[[:space:]]$' "$file" > /dev/null 2>&1; then
echo "❌ Trailing whitespace found in: $file"
grep -n '[[:space:]]$' "$file" | head -10
if [ $(grep -c '[[:space:]]$' "$file") -gt 10 ]; then
echo " ... and $(($(grep -c '[[:space:]]$' "$file") - 10)) more lines"
Comment on lines +64 to +65
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Copilot AI Nov 14, 2025

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The head -10 command limits the display to 10 lines but doesn't affect the count in line 64. This means if there are exactly 10 lines with trailing whitespace, line 64 will calculate (10 - 10) = 0 and display "... and 0 more lines", which is confusing.

Consider changing the condition to check if the count is greater than 10:

if [ $(grep -c '[[:space:]]$' "$file") -gt 10 ]; then
  EXTRA=$(($(grep -c '[[:space:]]$' "$file") - 10))
  echo "   ... and $EXTRA more lines"
fi

Or simplify by checking if EXTRA is greater than 0.

Suggested change
if [ $(grep -c '[[:space:]]$' "$file") -gt 10 ]; then
echo " ... and $(($(grep -c '[[:space:]]$' "$file") - 10)) more lines"
EXTRA=$(($(grep -c '[[:space:]]$' "$file") - 10))
if [ "$EXTRA" -gt 0 ]; then
echo " ... and $EXTRA more lines"

Copilot uses AI. Check for mistakes.
Comment on lines +62 to +65
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Copilot AI Nov 14, 2025

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The grep command on line 64 is executed multiple times within the same if block, which is inefficient. Consider storing the count in a variable first:

TRAILING_COUNT=$(grep -c '[[:space:]]$' "$file")
echo "❌ Trailing whitespace found in: $file"
grep -n '[[:space:]]$' "$file" | head -10
if [ "$TRAILING_COUNT" -gt 10 ]; then
  echo "   ... and $(($TRAILING_COUNT - 10)) more lines"
fi

This avoids running grep multiple times on the same file.

Suggested change
echo "❌ Trailing whitespace found in: $file"
grep -n '[[:space:]]$' "$file" | head -10
if [ $(grep -c '[[:space:]]$' "$file") -gt 10 ]; then
echo " ... and $(($(grep -c '[[:space:]]$' "$file") - 10)) more lines"
TRAILING_COUNT=$(grep -c '[[:space:]]$' "$file")
echo "❌ Trailing whitespace found in: $file"
grep -n '[[:space:]]$' "$file" | head -10
if [ "$TRAILING_COUNT" -gt 10 ]; then
echo " ... and $(($TRAILING_COUNT - 10)) more lines"

Copilot uses AI. Check for mistakes.
fi
echo "1" >> "$TEMP_FILE"
fi
done <<< "$CHANGED_FILES"

ERRORS_FOUND=$(wc -l < "$TEMP_FILE" 2>/dev/null || echo "0")
rm -f "$TEMP_FILE"

if [ "$ERRORS_FOUND" -gt 0 ]; then
echo ""
echo "❌ Found trailing whitespace in $ERRORS_FOUND file(s)."
echo "Please remove trailing whitespace from the files listed above."
exit 1
else
echo "✅ No trailing whitespace found in changed files."
exit 0
fi
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