# Copyright 2018 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/rust/rustc_artifact.gni")

# Defines a Rust unit test, without also compiling a separate binary or library
# target.
#
# Parameters
#
#   name
#     Name of the test binary, also used as the crate name as defined in its
#     manifest file. If not specified, it is assumed to be the same as the
#     target name.
#
#   version
#     Semver version of the crate as seen on crates.io.
#
#   edition
#     Edition of the Rust language to be used.
#     Options are "2015" and "2018". If unsure, choose "2018".
#
#   deps (optional)
#     List of rust_library GN targets on which this crate depends.
#     Third party crates can be included through paths like
#     "//third_party/rust_crates:<cratename>",
#
#   non_rust_deps (optional)
#     List of non-rust_library GN targets on which this crate depends.
#
#   test_environments (optional)
#     What environments the unit 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 environments parameter on //build/testing/test_spec.gni for more
#     details.
#
#   source_root (optional)
#     Location of the crate root (e.g. `src/main.rs` or `src/lib.rs`).
#     This should usually be 'src/lib.rs/ for libraries (the default)
#     and `src/main.rs` for binaries.
#
#   features (optional)
#     A list of conditional compilation flags to enable. This can be used to set features for crates
#     built in-tree which are also published to crates.io. This would be passed to rustc as
#     '--cfg feature=XXX'
#
# Example of usage:
#
#   rustc_test("foo_test") {
#     source_root = "src/foo_test.rs",
#     deps = [
#       "//src/lib/foo/bar",
#       "//third_party/rust_crates:clap",
#       "//third_party/rust_crates:serde",
#       "//third_party/rust_crates:slab",
#     ]
#   }
template("rustc_test") {
  rustc_artifact(target_name) {
    forward_variables_from(invoker,
                           [
                             "name",
                             "version",
                             "edition",
                             "deps",
                             "non_rust_deps",
                             "test_environments",
                             "source_root",
                             "features",
                             "visibility",
                             "with_lto",
                             "__unstable_netstack3_only_specialization_bypass",
                           ])
    if (!defined(source_root)) {
      source_root = "src/lib.rs"
    }
    type = "bin"
    only_unit_tests = true
    testonly = true
  }
}