tools/devshell/lib/dart_utils.sh

# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# The functions here are used to compile Dart commands, but may be generalized
# later to support compiling other tools if needed. This functionality is also
# covered by host-tools code, but host-tools doesn't correctly generate the
# metadata entries in //out/default/tool_paths.json for Dart binaries.

# Build the tool, but only if necessary.
function _build {
  local target="$1"
  local executable="$2"

  fx-info "Building required tool \"${target}\"..."
  if ! fx-command-run build "${target}"; then
    fx-error "Could not compile ${executable##*/}"
    exit 1
  fi
}

# Run a dart tool, checking first if it needs to be built. The calling script
# must call `fx-config-read` before calling this function because it depends on
# HOST_OUT_DIR.
function run-dart-tool {
  local tool_name="$1"
  shift

  local executable="${HOST_OUT_DIR}/dart-tools/${tool_name}"
  local tool_build_target="${HOST_OUT_DIR##*/}/dart-tools/${tool_name}"

  # Rebuild if the binary isn't present. Generally, the Dart executable is
  # rebuilt as part of an `fx build` so always up-to-date.
  if [[ ! -f "${executable}" ]]; then
    _build "${tool_build_target}" "${executable}"
  fi

  "${executable}" "$@"
  local status=$?
  if [[ "${status}" == 253 ]]; then
    # This error typically occurs when files that the executable depends on
    # have been updated, but the executable itself has not. Rebuilding the
    # command.
    _build "${tool_build_target}" "${executable}"
    "${executable}" "$@"
    status=$?
  fi
  exit "${status}"
}