pre-commit.hook

#!/bin/bash
#
# Pre-commit hook
#  1. Formatting check (always; fast)
#     - C/C++ files: clang-format
#     - JS/CSS/HTML files: prettier (if available)
#  2. Build + test (conditional on staged source/build files)
#     - Skipped on docs-only / config-only / web-only commits
#     - Mirrors what the CI runs locally so a green commit ≈ green CI
#  3. Optional local extension: if ./pre-commit.local.hook exists and is
#     executable, it runs after phases 1+2 succeed.  Use for per-developer
#     checks that shouldn't live in the public repo.  Gitignored.
#
# Install: ./install-git-hooks.sh
# Bypass:  git commit --no-verify
#

# Change to repository root
cd "$(git rev-parse --show-toplevel)" || exit 1

# Color output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Optional local-only pre-commit extension.  If ./pre-commit.local.hook
# exists and is executable, it runs after the tracked phases succeed.
# The local hook is gitignored (*.local.hook).  Failure (non-zero exit)
# blocks the commit just like any other phase.
run_local_extension() {
   if [ -x "./pre-commit.local.hook" ]; then
      ./pre-commit.local.hook
      local rc=$?
      if [ "$rc" -ne 0 ]; then
         echo ""
         echo -e "${RED}Local pre-commit extension failed (exit $rc).${NC}"
         echo -e "${YELLOW}Bypass: git commit --no-verify${NC}"
         exit "$rc"
      fi
   fi
}

# -----------------------------------------------------------------------------
# Phase 1 — formatting
# -----------------------------------------------------------------------------

if [ ! -f "./format_code.sh" ]; then
   echo -e "${RED}ERROR: format_code.sh not found!${NC}"
   exit 1
fi

# Check the STAGED index content (--staged), not the working tree (--changed):
# the index is what this commit records, so a working tree formatted after a
# `git add` can't mask an unformatted staged blob.
echo -e "${BLUE}Pre-commit: checking formatting of staged content…${NC}"
./format_code.sh --staged --check
FORMAT_RESULT=$?

if [ $FORMAT_RESULT -ne 0 ]; then
   echo ""
   echo -e "${RED}Formatting check failed.${NC}"
   echo -e "${YELLOW}Fix with: ./format_code.sh --changed${NC}"
   echo -e "${YELLOW}Then re-stage and commit again.${NC}"
   echo -e "${YELLOW}Bypass:   git commit --no-verify${NC}"
   exit 1
fi

# -----------------------------------------------------------------------------
# Phase 2 — build + test (conditional)
# -----------------------------------------------------------------------------
# Only run the CI test suite when the staged changes can actually affect it.
# Source code, headers, the test suite itself, and the build configuration
# trigger it.  Pure docs / config / web-only commits skip the test phase so
# fast-iteration cycles stay fast.

STAGED=$(git diff --cached --name-only --diff-filter=ACMR)

SHOULD_TEST=0
if [ -n "$STAGED" ]; then
   if echo "$STAGED" | grep -qE '^(src|include|common|tests|benchmarks|cmake)/|(^|/)CMakeLists\.txt$|\.cmake$'; then
      SHOULD_TEST=1
   fi
fi

if [ "$SHOULD_TEST" -eq 0 ]; then
   echo -e "${GREEN}Pre-commit: format OK; no source/build files staged, skipping test suite.${NC}"
   run_local_extension
   exit 0
fi

# Locate an existing build directory.  Prefer build-debug (the developer's
# daily driver per CLAUDE.md); fall back to build-ci or other variants.
BUILD_DIR=""
for d in build-debug build-ci build-full build; do
   if [ -f "$d/CMakeCache.txt" ]; then
      BUILD_DIR="$d"
      break
   fi
done

if [ -z "$BUILD_DIR" ]; then
   echo -e "${YELLOW}Pre-commit: format OK; no build directory found, skipping test suite.${NC}"
   echo -e "${YELLOW}  Bootstrap with: cmake --preset debug${NC}"
   run_local_extension
   exit 0
fi

BUILD_LOG=$(mktemp -t dawn-precommit-build.XXXXXX.log)
TEST_LOG=$(mktemp -t dawn-precommit-test.XXXXXX.log)
trap 'rm -f "$BUILD_LOG" "$TEST_LOG"' EXIT

echo -e "${BLUE}Pre-commit: building tests-ci in $BUILD_DIR…${NC}"
if ! make -C "$BUILD_DIR" -j"$(nproc)" tests-ci > "$BUILD_LOG" 2>&1; then
   echo ""
   echo -e "${RED}Test build FAILED.  Last 30 lines:${NC}"
   tail -30 "$BUILD_LOG"
   PRESERVED=$(mktemp -t dawn-precommit-build-failed.XXXXXX.log)
   cp "$BUILD_LOG" "$PRESERVED"
   echo ""
   echo -e "${YELLOW}Full log preserved at: $PRESERVED${NC}"
   echo -e "${YELLOW}Bypass:                git commit --no-verify${NC}"
   exit 1
fi

echo -e "${BLUE}Pre-commit: running CI test suite…${NC}"
if ! ctest --test-dir "$BUILD_DIR" --output-on-failure --no-tests=error -L ci > "$TEST_LOG" 2>&1; then
   echo ""
   echo -e "${RED}Test suite FAILED.  Failing cases:${NC}"
   grep -E "FAIL:|\*\*\*Failed|tests failed" "$TEST_LOG" | head -20
   PRESERVED=$(mktemp -t dawn-precommit-test-failed.XXXXXX.log)
   cp "$TEST_LOG" "$PRESERVED"
   echo ""
   echo -e "${YELLOW}Reproduce: ctest --test-dir $BUILD_DIR --output-on-failure -L ci${NC}"
   echo -e "${YELLOW}Full log:  $PRESERVED${NC}"
   echo -e "${YELLOW}Bypass:    git commit --no-verify${NC}"
   exit 1
fi

PASS_LINE=$(grep -E "tests passed" "$TEST_LOG" | tail -1)
if [ -n "$PASS_LINE" ]; then
   echo -e "${GREEN}Pre-commit: $PASS_LINE${NC}"
else
   echo -e "${GREEN}Pre-commit: test suite passed.${NC}"
fi

run_local_extension
exit 0