chore(common): add unit tests for compile

Author: nickchecan

Makefile

@@ -6,7 +6,7 @@ ROOT_DIR := $(CURDIR)
 BUILDPACK_DIR := $(ROOT_DIR)
 PYTHON_BIN ?= python3
 
-.PHONY: test-buildpack clean-test-buildpack test-detect smoke-test start-local
+.PHONY: test-buildpack clean-test-buildpack test-detect test-compile smoke-test start-local
 
 # Reset the temporary staging directories used for local buildpack testing.
 clean-test-buildpack:
@@ -16,6 +16,10 @@ clean-test-buildpack:
 test-detect:
 	@bash ./test/unit/detect_test.sh
 
+# Run unit tests for the compile script with stubbed python and uv commands.
+test-compile:
+	@bash ./test/unit/compile_test.sh
+
 # Run the sample app through detect, compile, and release using the same
 # temporary directories each time so local testing is repeatable.
 test-buildpack: clean-test-buildpack

test/unit/compile_test.sh

@@ -0,0 +1,237 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+COMPILE_SCRIPT="$ROOT_DIR/bin/compile"
+TMP_DIR="$(mktemp -d /tmp/compile-test.XXXXXX)"
+TEST_ROOT="$TMP_DIR/test-root"
+FAKE_BIN_DIR="$TMP_DIR/fake-bin"
+
+cleanup() {
+  rm -rf "$TMP_DIR"
+}
+
+trap cleanup EXIT
+
+assert_exit_code() {
+  local actual="$1"
+  local expected="$2"
+  local message="$3"
+
+  if [ "$actual" -ne "$expected" ]; then
+    echo "FAIL: $message"
+    echo "Expected exit code: $expected"
+    echo "Actual exit code: $actual"
+    exit 1
+  fi
+}
+
+assert_contains() {
+  local actual="$1"
+  local expected="$2"
+  local message="$3"
+
+  if [[ "$actual" != *"$expected"* ]]; then
+    echo "FAIL: $message"
+    echo "Expected to find: $expected"
+    echo "Actual output: $actual"
+    exit 1
+  fi
+}
+
+assert_file_contains() {
+  local file_path="$1"
+  local expected="$2"
+  local message="$3"
+
+  if ! grep -Fq -- "$expected" "$file_path"; then
+    echo "FAIL: $message"
+    echo "Expected to find: $expected"
+    echo "In file: $file_path"
+    echo "Actual file contents:"
+    cat "$file_path"
+    exit 1
+  fi
+}
+
+assert_path_exists() {
+  local file_path="$1"
+  local message="$2"
+
+  if [ ! -e "$file_path" ]; then
+    echo "FAIL: $message"
+    echo "Missing path: $file_path"
+    exit 1
+  fi
+}
+
+setup_fake_commands() {
+  mkdir -p "$FAKE_BIN_DIR"
+
+  cat > "$FAKE_BIN_DIR/python3" <<'EOF'
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [ "$#" -ge 2 ] && [ "$1" = "-c" ] && [ "$2" = "import sys; print(f\"{sys.version_info.major}.{sys.version_info.minor}\")" ]; then
+  printf '3.13\n'
+  exit 0
+fi
+
+if [ "$#" -ge 3 ] && [ "$1" = "-m" ] && [ "$2" = "pip" ]; then
+  log_file="${TEST_ROOT}/pip.log"
+  mkdir -p "$(dirname "$log_file")"
+  printf '%s\n' "$*" >> "$log_file"
+
+  target_dir=""
+  requirements_file=""
+
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      --target)
+        shift
+        target_dir="$1"
+        ;;
+      -r)
+        shift
+        requirements_file="$1"
+        ;;
+    esac
+    shift || true
+  done
+
+  if [ -n "$target_dir" ]; then
+    mkdir -p "$target_dir"
+    touch "$target_dir/fake-installed-package.txt"
+  fi
+
+  if [ -n "$requirements_file" ]; then
+    printf '%s\n' "$requirements_file" > "${TEST_ROOT}/last-requirements-file.txt"
+  fi
+
+  exit 0
+fi
+
+echo "Unexpected python3 invocation: $*" >&2
+exit 1
+EOF
+
+  cat > "$FAKE_BIN_DIR/uv" <<'EOF'
+#!/usr/bin/env bash
+set -euo pipefail
+
+log_file="${TEST_ROOT}/uv.log"
+mkdir -p "$(dirname "$log_file")"
+printf '%s\n' "$*" >> "$log_file"
+
+if [ "$1" = "export" ]; then
+  output_file=""
+
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      -o)
+        shift
+        output_file="$1"
+        ;;
+    esac
+    shift || true
+  done
+
+  cat > "$output_file" <<'REQ'
+fastapi==0.135.3
+uvicorn==0.44.0
+REQ
+  exit 0
+fi
+
+echo "Unexpected uv invocation: $*" >&2
+exit 1
+EOF
+
+  chmod +x "$FAKE_BIN_DIR/python3" "$FAKE_BIN_DIR/uv"
+}
+
+run_compile() {
+  local build_dir="$1"
+  local cache_dir="$2"
+  local env_dir="$3"
+  local output_file="$TEST_ROOT/output.txt"
+
+  set +e
+  PATH="$FAKE_BIN_DIR:/usr/bin:/bin" TEST_ROOT="$TEST_ROOT" "$COMPILE_SCRIPT" "$build_dir" "$cache_dir" "$env_dir" >"$output_file" 2>&1
+  status=$?
+  set -e
+
+  output="$(cat "$output_file")"
+}
+
+test_compile_succeeds_for_locked_uv_project() {
+  # Arrange
+  local build_dir="$TEST_ROOT/success/build"
+  local cache_dir="$TEST_ROOT/success/cache"
+  local env_dir="$TEST_ROOT/success/env"
+  local site_packages_dir="$build_dir/.python_packages/lib/python3.13/site-packages"
+  local profile_file="$build_dir/.profile.d/python.sh"
+  local export_file="$build_dir/.uv-export-requirements.txt"
+
+  mkdir -p "$build_dir" "$cache_dir" "$env_dir"
+  touch "$build_dir/pyproject.toml" "$build_dir/uv.lock"
+  setup_fake_commands
+
+  # Act
+  run_compile "$build_dir" "$cache_dir" "$env_dir"
+
+  # Assert
+  assert_exit_code "$status" 0 "compile should succeed for a locked uv project"
+  assert_contains "$output" "Detected uv project with lockfile. Installing dependencies with uv." "compile should announce supported uv projects"
+  assert_path_exists "$site_packages_dir" "compile should create the staged site-packages directory"
+  assert_path_exists "$profile_file" "compile should write a profile script for runtime imports"
+  assert_path_exists "$export_file" "compile should write the exported requirements file"
+  assert_file_contains "$profile_file" "$site_packages_dir" "profile script should add staged dependencies to PYTHONPATH"
+  assert_file_contains "$TEST_ROOT/uv.log" "export --locked --format requirements-txt --no-emit-local -o $export_file" "compile should export locked third-party dependencies"
+  assert_file_contains "$TEST_ROOT/pip.log" "-m pip install uv" "compile should install uv with pip"
+  assert_file_contains "$TEST_ROOT/pip.log" "--no-deps --target $site_packages_dir -r $export_file" "compile should install exported dependencies into the staged site-packages directory"
+}
+
+test_compile_adds_src_directory_to_pythonpath_when_present() {
+  # Arrange
+  local build_dir="$TEST_ROOT/src-layout/build"
+  local cache_dir="$TEST_ROOT/src-layout/cache"
+  local env_dir="$TEST_ROOT/src-layout/env"
+  local profile_file="$build_dir/.profile.d/python.sh"
+
+  mkdir -p "$build_dir/src" "$cache_dir" "$env_dir"
+  touch "$build_dir/pyproject.toml" "$build_dir/uv.lock"
+  setup_fake_commands
+
+  # Act
+  run_compile "$build_dir" "$cache_dir" "$env_dir"
+
+  # Assert
+  assert_exit_code "$status" 0 "compile should succeed for src-layout projects"
+  assert_file_contains "$profile_file" "$build_dir/src" "profile script should add src layout projects to PYTHONPATH"
+}
+
+test_compile_fails_when_lockfile_is_missing() {
+  # Arrange
+  local build_dir="$TEST_ROOT/missing-lock/build"
+  local cache_dir="$TEST_ROOT/missing-lock/cache"
+  local env_dir="$TEST_ROOT/missing-lock/env"
+
+  mkdir -p "$build_dir" "$cache_dir" "$env_dir"
+  touch "$build_dir/pyproject.toml"
+  setup_fake_commands
+
+  # Act
+  run_compile "$build_dir" "$cache_dir" "$env_dir"
+
+  # Assert
+  assert_exit_code "$status" 1 "compile should fail when uv.lock is missing"
+  assert_contains "$output" "No supported uv project found. Expected both pyproject.toml and uv.lock." "compile should explain why unsupported projects fail"
+}
+
+test_compile_succeeds_for_locked_uv_project
+test_compile_adds_src_directory_to_pythonpath_when_present
+test_compile_fails_when_lockfile_is_missing
+
+echo "PASS: compile unit tests"