def test_read_file_ok():
    assert.eq(io.read_file("support/file_to_read.txt"), "Hello, world!\n")
    assert.eq(io.read_file("//testdata/misc/support/file_to_read.txt"), "Hello, world!\n")

def test_read_file_fail():
    assert.fails(lambda: io.read_file("missing_file.txt"), "no such file")
    assert.fails(lambda: io.read_file("//missing_file.txt"), "no such file")
    assert.fails(lambda: io.read_file("../../../README.md"), "outside the package root")

test_read_file_ok()
test_read_file_fail()