"""Command line interface tests for llvm.py build.

Note that although this uses the unittest framework, it does *not* contain unit
tests.

"""
import os

from shutil import rmtree
from tempfile import mkdtemp

from llvmtestcase import LLVMTestCase, require_command_arg, debug


def create_empty_file(path):
    open(path, "wt").close()


class Testllvmbuild(LLVMTestCase):

    @classmethod
    def llvm_build(cls, *args, **kwargs):
        return cls.command_with_defaults("build", *args, **kwargs)

    def setUp(self):
        self.buildDir = mkdtemp()

    def tearDown(self):
        rmtree(self.buildDir)

    @require_command_arg("--build-dir")
    def test_build_dir_is_compulsory(self):
        """Test that we get an error if we don't pass the build dir."""
        self.run_with_output(self.llvm_build())

    def test_dry_run(self):
        """
        Test that we at least dump the expected command. It's difficult to check
        whether we would actually run it correctly without depending too much on
        external factors.
        """
        create_empty_file(os.path.join(self.buildDir, "build.ninja"))

        output = self.run_with_output(
            self.llvm_build(
                "--dry-run",
                "--build-dir",
                self.buildDir,
                "--build-flag=-j8",
                "--build-flag",
                "llc",
                "--build-flag",
                "llvm-mc"))

        self.assertEqual(output,
                         "{}$ ninja -j8 llc llvm-mc\n".format(self.buildDir))