Add PEP517 check suite and support disabling setup.py for sdists

[abn]

1. Adds scaffolding and a few integration tests for PEP517 tests.
2. Support opt-in disabling of setup.py in sdists.
3. Support "tool.poetry.build" section to support "generate-setup-file"

[tool.poetry.build]
generate-setup-file = true

This change will also mean that tool.poetry.build = "build.py" usage is now deprecated in favour of tool.poetry.build.script. The older cofiguration will continue to work as expected.

I have also added some additional converage for PEP-517 concerns in a new github actions workflow.

Integration Test Suite Notes

To run pytest integration cases locally, you can do so using one of the following.

1. Use tox. This runs only the integration tests placed in tests/integration.

tox -e integration

2. Using pytest. Using the --integration option will enable all tests with the integration marker. You can restrict running only these tests by specifying tests/integration directory as an argument.

pytest --integration

If developing/adding tests, you can simply mark a test as integration, and it will only be executed when the integration suite is executed.

[abn]

PEP-517 tests seem to pass okay locally on all versions, but CI does not like them. Need to investigate a bit further.

EDIT: This was resolved.

[abn]

@sdispater any thought on the naming for the configuration section? The idea is to reuse this section for project specific configuration. Ideally would like to evolve this further later to provide project specific overrides etc.

[sdispater]

The table to store the setting should be tool.poetry.build.config (or even a simpler tool.poetry.build where it would be possible to put build-related settings) instead of tool.poetry.config.

The reason for that is I don't want people to start thinking that they can put any setting in this section (we already have poetry.toml for that). So having a build section would be better. However this will break the projects of people currently using the build property to specify a build script.

I don't know how many users use this feature, and I don't mind breaking it this it was never documented and it needs improvements anyway but that's something to have in mind and we need to find a way to make it work.

[abn]

@sdispater I fear quite a few people are using this feature (based on incoming issues) as this is the only way today the extensions work. I am reluctant to recommend removing it as it is a useful feature.

Also, tool.poetry.toml is not really documented either as far as I can tell.

[sdispater]

@abn When I said poetry.toml, I meant the poetry.toml file that's used for the --local option of the config command (see https://python-poetry.org/docs/configuration/#local-configuration).

If we are not comfortable in removing it, we will need to make it backward compatible, meaning we will need to support both (build as a string pointing to a build script and build as a table representing a build configuration).

So basically people would need to migrate from:

build = "my_script.py"

to

[tool.poetry.build.config]
script = "my_script.py"
generate-setup-file = false

[abn]

@sdispater the change has been applied.

[sdispater]

Looks good to me 👍

[ghost]

Hello 2023 people!

Once again we have a great poetry point release breaking existing features.

This previous statement is no longer true:

we will need to make it backward compatible, meaning we will need to support both (build as a string pointing to a build script and build as a table representing a build configuration).

The previous syntax is now gone and your builds are breaking until you use the new syntax (which i couldn't find/search in the docs anywhere? it only exists here?) of:

[tool.poetry.build.config]
script = "my_script.py"
generate-setup-file = true

[phillipuniverse]

@mattpeople that config doesn't work, here's what I have:

  [tool.poetry.build.config]
  generate-setup-file = true

and I get this error:

The Poetry configuration is invalid:
  - [build] {'config': {'generate-setup-file': True}} is not valid under any of the given schemas

The one in the description of this PR does work:

  [tool.poetry.build]
  generate-setup-file = true