CLI Application Validation Reference

# Build → Execute → Capture → Verify (always this order)
BUILD_CMD="cargo build --release"  # or: go build -o ./bin/app, npm run build
BINARY="./target/release/myapp"    # adjust for language

# 1. Build and verify binary exists
$BUILD_CMD 2>&1 | tee build.log
[ $? -ne 0 ] && echo "BUILD FAILED" && cat build.log && exit 1

# 2. Verify binary is executable
[ ! -x "$BINARY" ] && echo "Binary not found at $BINARY" && exit 1
$BINARY --version  # Smoke test

# 3. Execute with real input, capture everything
$BINARY process input.json > stdout.txt 2> stderr.txt
EXIT_CODE=$?

# 4. Verify
echo "Exit code: $EXIT_CODE"
echo "=== STDOUT ===" && cat stdout.txt
echo "=== STDERR ===" && cat stderr.txt

# Install → Verify Entry Point → Execute → Capture → Verify

# 1. Install in editable mode (creates real entry points)
pip install -e . 2>&1 | tee install.log
[ $? -ne 0 ] && echo "INSTALL FAILED" && cat install.log && exit 1

# 2. Verify the entry point exists and is callable
#    Option A: If pyproject.toml defines [project.scripts]
which my-tool  # Must resolve to a real path, not "not found"
my-tool --help 2>&1 | head -5

#    Option B: If the project uses __main__.py (python -m invocation)
python3 -m my_module --help 2>&1 | head -5

# 3. Execute with real input AS AN END USER WOULD
my-tool run input.json > stdout.txt 2> stderr.txt
# OR: python3 -m my_module run input.json > stdout.txt 2> stderr.txt
EXIT_CODE=$?

# 4. Verify
echo "Exit code: $EXIT_CODE"
echo "=== STDOUT ===" && cat stdout.txt
echo "=== STDERR ===" && cat stderr.txt