# Copyright 2019 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.

import("//build/dart/dart_library.gni")
import("//build/dart/toolchain.gni")
import("//build/testing/test_spec.gni")

# Defines a Dart test suite.
#
# Parameters
#
#   sources
#     Required: The list of public dart sources files defining the test.
#       NOTE: this template assumes that all test entrypoints are defined by
#       files with a suffix of "_test.dart".
#
#   source_dir
#     Optional: The directory of test sources files. Defaults to "test".
#
#   deps
#     Optional: Dart dependencies of the test.
#
#   non_dart_deps
#     Optional: List of labels this package depends on that are not Dart
#       packages.
#
#   environments
#     Optional: What environments this test should target. Only used here for
#       linux and mac tests, with a default value of a general linux/mac
#       environment (as a function of $current_os).
#       See //build/testing/test_spec.gni for more details.
#
#   args
#     Optional: Command-line arguments to pass to the Dart application. These
#       arguments are inserted ahead of any arguments given to the invocation,
#       like the program/args entry in a component manifest.
#
template("dart_test") {
  assert(defined(invoker.sources), "dart_test() must specify sources")

  _main_target_name = target_name
  _dart_library_target_name = "${target_name}_dart_library"
  _test_grouping_target_name = "${target_name}_test_grouping"
  _copy_target_name = "${target_name}_copy"
  _snapshot_target_name = "${target_name}_snapshot"
  _spec_target_name = "${target_name}_spec"

  if (defined(invoker.source_dir)) {
    _source_dir = invoker.source_dir
  } else {
    _source_dir = "test"
  }

  dart_library(_dart_library_target_name) {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "sources",
                           ])
    source_dir = _source_dir
    infer_package_name = true
  }

  # Create a single, grouped test file, as snapshot files correspond to a single
  # entrypoint.
  _grouped_main_file = "$target_gen_dir/${_main_target_name}_grouped.dart"

  action(_test_grouping_target_name) {
    script = "//build/dart/group_tests.py"
    outputs = [
      _grouped_main_file,
    ]
    args = [
      "--out",
      rebase_path(_grouped_main_file),
    ]
    foreach(src, invoker.sources) {
      args += [
        "--source",
        rebase_path("$_source_dir/$src"),
      ]
    }
  }

  _dart_binary = "$target_gen_dir/$_main_target_name/dart"
  copy(_copy_target_name) {
    sources = [
      "//prebuilt/third_party/dart/$host_os-$host_cpu/bin/dart",
    ]
    outputs = [
      _dart_binary,
    ]
  }

  # Creates a snapshot file, which allows the test to be invoked hermetically.
  _snapshot = "$target_gen_dir/${target_name}.snapshot"
  _dart_target_gen_dir =
      get_label_info(":anything($dart_toolchain)", "target_gen_dir")
  _packages_path = "$_dart_target_gen_dir/${_dart_library_target_name}.packages"

  action(_snapshot_target_name) {
    depfile = "${_snapshot}.d"

    outputs = [
      _snapshot,
    ]

    script = _dart_binary

    # The snapshot path needs to be rebased on top of the root build dir so
    # that the resulting depfile gets properly formatted.
    _rebased_snapshot = rebase_path(_snapshot, root_build_dir)
    _rebased_depfile = rebase_path(depfile)
    _rebased_packages_path = rebase_path(_packages_path)

    args = [
      "--snapshot=$_rebased_snapshot",
      "--snapshot-depfile=$_rebased_depfile",
      "--packages=$_rebased_packages_path",
      rebase_path(_grouped_main_file),
    ]

    deps = dart_sdk_deps + [
             ":$_dart_library_target_name",
             ":$_test_grouping_target_name",
             ":$_copy_target_name",
           ]

    metadata = {
      test_runtime_deps = [
        _dart_binary,
        _snapshot,
      ]
    }
  }

  _invocation = "$root_out_dir/$_main_target_name"
  test_spec(_spec_target_name) {
    name = _main_target_name
    location = _invocation

    forward_variables_from(invoker,
                           [
                             "deps",
                             "environments",
                           ])
    deps += [ ":$_snapshot_target_name" ]
    if (defined(invoker.non_dart_deps)) {
      deps += invoker.non_dart_deps
    }
  }

  # Creates a convenience script to invoke the test.
  action(_main_target_name) {
    script = "//build/dart/gen_dart_test_invocation.py"

    inputs = [
      _snapshot,
    ]
    outputs = [
      _invocation,
    ]

    args = [
      "--wd",

      # TODO(crbug.com/gn/56): Rebasing root_build_dir alone yields a path
      # component that leaves root_build_dir, preventing portability.
      rebase_path("$root_build_dir/dummy/..",
                  get_path_info(_invocation, "dir")),
      "--out",
      rebase_path(_invocation),
      "--dart",
      rebase_path(_dart_binary, root_build_dir),
      "--snapshot",
      rebase_path(_snapshot, root_build_dir),
    ]

    # TODO(joshuaseaton): use test_spec's `command` field when fx supports
    # running tests out of $root_build_dir/tests.json.
    # CL to back out: https://fuchsia-review.googlesource.com/269458
    if (defined(invoker.args) && invoker.args != []) {
      argstr = ""
      foreach(arg, invoker.args) {
        argstr += "\"" + arg + "\" "
      }

      args += [
        "--args",
        argstr,
      ]
    }

    deps = dart_sdk_deps + [
             ":$_snapshot_target_name",
             ":$_spec_target_name",
           ]
  }
}