Carlo Cabrera 98a53e4781
language/python: support python3 from PATH in #detected_python_shebang
Some formulae are flexible about the version of Python3 that they use.
However, when we use `#detected_python_shebang` on these formulae, they
become coupled to the specific version of Python3 declared in the
formula.

This is harmful because
1. it prevents us from using `uses_from_macos "python"` even in formulae
   where we should be able to
2. it forces us to rebuild the formula whenever we make changes to the
   Python dependency when nothing but the shebang would have changed as
   a consequence of the rebuild

For an example of this, see Homebrew/homebrew-core#107905.

I'd also like to do this to get rid of some really terrible hacks we
have in `glib-utils` as a means of decoupling `glib` from the specific
versioned Python dependency it used to have.

See Homebrew/homebrew-core#103916, or Homebrew/homebrew-core#106045 for
a proposal to give the same treatment to `gobject-introspection`.
2022-08-13 01:11:09 +08:00

59 lines
1.3 KiB
Ruby

# typed: false
# frozen_string_literal: true
require "language/python"
require "utils/shebang"
describe Language::Python::Shebang do
let(:file) { Tempfile.new("python-shebang") }
let(:python_f) do
formula "python@3.11" do
url "https://brew.sh/python-1.0.tgz"
end
end
let(:f) do
formula "foo" do
url "https://brew.sh/foo-1.0.tgz"
depends_on "python@3.11"
end
end
before do
file.write <<~EOS
#!/usr/bin/python2
a
b
c
EOS
file.flush
end
after { file.unlink }
describe "#detected_python_shebang" do
it "can be used to replace Python shebangs" do
expect(Formulary).to receive(:factory).with(python_f.name).and_return(python_f)
Utils::Shebang.rewrite_shebang described_class.detected_python_shebang(f, use_python_from_path: false), file
expect(File.read(file)).to eq <<~EOS
#!#{HOMEBREW_PREFIX}/opt/python@3.11/bin/python3.11
a
b
c
EOS
end
it "can be pointed to a `python3` in PATH" do
Utils::Shebang.rewrite_shebang described_class.detected_python_shebang(f, use_python_from_path: true), file
expect(File.read(file)).to eq <<~EOS
#!/usr/bin/env python3
a
b
c
EOS
end
end
end