Add development and testing infrastructure

Added build targets:
- make asan        - AddressSanitizer for memory bugs
- make debug       - Debug symbols
- make valgrind    - Valgrind helper
- make check       - Static analysis (cppcheck, clang-tidy)

Added test scripts:
- test_basic.sh    - Basic functionality tests
  * Server startup
  * SSH connection
  * Message logging

- test_stress.sh   - Load testing
  * Configurable client count
  * Configurable duration
  * Automatic cleanup

Updated .gitignore:
- test.log
- *.dSYM/

Philosophy: Simple, minimal, Unix-style tools.
No dependencies on complex test frameworks.

.gitignore

@@ -6,3 +6,5 @@ host_key
 host_key.pub
 *.swp
 .DS_Store
+test.log
+*.dSYM/

Makefile

@@ -23,7 +23,7 @@ SOURCES = $(wildcard $(SRC_DIR)/*.c)
 OBJECTS = $(SOURCES:$(SRC_DIR)/%.c=$(OBJ_DIR)/%.o)
 TARGET = tnt
 
-.PHONY: all clean install uninstall
+.PHONY: all clean install uninstall debug release asan valgrind check info
 
 all: $(TARGET)
 
@@ -56,6 +56,19 @@ release: CFLAGS += -O3 -DNDEBUG
 release: clean $(TARGET)
 	strip $(TARGET)
 
+asan: CFLAGS += -g -fsanitize=address -fno-omit-frame-pointer
+asan: LDFLAGS += -fsanitize=address
+asan: clean $(TARGET)
+	@echo "AddressSanitizer build complete. Run with: ASAN_OPTIONS=detect_leaks=1 ./tnt"
+
+valgrind: debug
+	@echo "Run: valgrind --leak-check=full --track-origins=yes ./tnt"
+
+# Static analysis
+check:
+	@command -v cppcheck >/dev/null 2>&1 && cppcheck --enable=warning,performance --quiet src/ || echo "cppcheck not installed"
+	@command -v clang-tidy >/dev/null 2>&1 && clang-tidy src/*.c -- -Iinclude $(INCLUDES) || echo "clang-tidy not installed"
+
 # Show build info
 info:
 	@echo "Compiler: $(CC)"

test_basic.sh

@@ -0,0 +1,60 @@
+#!/bin/sh
+# Basic functional tests
+# Usage: ./test_basic.sh
+
+PORT=${PORT:-2222}
+PASS=0
+FAIL=0
+
+cleanup() {
+    kill $SERVER_PID 2>/dev/null
+    rm -f test.log
+}
+
+trap cleanup EXIT
+
+echo "=== TNT Basic Tests ==="
+
+# Start server
+./tnt -p $PORT >test.log 2>&1 &
+SERVER_PID=$!
+sleep 2
+
+# Test 1: Server started
+if kill -0 $SERVER_PID 2>/dev/null; then
+    echo "✓ Server started"
+    PASS=$((PASS + 1))
+else
+    echo "✗ Server failed to start"
+    FAIL=$((FAIL + 1))
+    exit 1
+fi
+
+# Test 2: SSH connection
+if timeout 5 ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null \
+    -o BatchMode=yes -p $PORT localhost exit 2>/dev/null; then
+    echo "✓ SSH connection works"
+    PASS=$((PASS + 1))
+else
+    echo "✗ SSH connection failed"
+    FAIL=$((FAIL + 1))
+fi
+
+# Test 3: Message logging
+echo "test message" | timeout 5 ssh -o StrictHostKeyChecking=no \
+    -o UserKnownHostsFile=/dev/null -p $PORT localhost >/dev/null 2>&1 &
+sleep 3
+if [ -f messages.log ]; then
+    echo "✓ Message logging works"
+    PASS=$((PASS + 1))
+else
+    echo "✗ Message logging failed"
+    FAIL=$((FAIL + 1))
+fi
+
+# Summary
+echo ""
+echo "PASSED: $PASS"
+echo "FAILED: $FAIL"
+[ $FAIL -eq 0 ] && echo "All tests passed" || echo "Some tests failed"
+exit $FAIL

test_stress.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+# Stress test for TNT server
+# Usage: ./test_stress.sh [num_clients]
+
+PORT=${PORT:-2222}
+CLIENTS=${1:-10}
+DURATION=${2:-30}
+
+echo "Starting TNT server on port $PORT..."
+./tnt -p $PORT &
+SERVER_PID=$!
+sleep 2
+
+if ! kill -0 $SERVER_PID 2>/dev/null; then
+    echo "Server failed to start"
+    exit 1
+fi
+
+echo "Spawning $CLIENTS clients for ${DURATION}s..."
+
+for i in $(seq 1 $CLIENTS); do
+    (
+        sleep $((i % 5))
+        echo "test user $i" | timeout $DURATION ssh -o StrictHostKeyChecking=no \
+            -o UserKnownHostsFile=/dev/null -p $PORT localhost \
+            >/dev/null 2>&1
+    ) &
+done
+
+echo "Running stress test..."
+sleep $DURATION
+
+echo "Cleaning up..."
+kill $SERVER_PID 2>/dev/null
+wait
+
+echo "Stress test complete"
+ps aux | grep tnt | grep -v grep && echo "WARNING: tnt process still running"