Support scripts with inline script metadata as input files

[chrysle]

Closes #2027.

Contributor checklist

• Included tests for the changes.
• PR title is short, clear, and ready to be included in the user-facing changelog.

Maintainer checklist

• Verified one of these labels is present: backwards incompatible, feature, enhancement, deprecation, bug, dependency, docs or skip-changelog as they determine changelog listing.
• Assign the PR to an existing or new milestone for the target version (following Semantic Versioning).

[chrysle]

@webknjaz please review; there isn't any other active maintainer left, as it seems..

[WhyNotHugo]

What's the use-case for this?

[chrysle]

Hmm, suppose you have a Python script that has dependencies, is probably often in use and not part of a package with corresponding metadata; then setting up an environment fastly would be possible through this functionality.

[chrysle]

@WhyNotHugo would you like to review this? We're really short on help ATM.

[webknjaz]

Should we also have tests for extras?

[webknjaz]

Oh, there's no explicit extras in the spec. But how about requires-python?

[chrysle]

I'm not sure how that would influence the build process?

[webknjaz]

It should reject incompatible runtimes, for example.

[webknjaz]

I recommend using (?x) to be able to make this multiline with comments.

[webknjaz]

pathlib is usually nicer

Suggested change

	os.path.basename(src_file).endswith(".py") and not is_setup_file
	Path(src_file).suffix == ".py" and not is_setup_file

[merwok]

The src path should probably be a local variable (not temporary like in the suggestion), to be used for suffix check here and open / read_text on lines below.

[webknjaz]

Suggested change

	if os.path.basename(src_file).endswith(".py"):
	if Path(src_file).suffix == ".py":

[webknjaz]

@chrysle sorry, I didn't have time lately. I'll try to come back for another review round during/after EuroPython.

[webknjaz]

@chrysle I clicked “rebase” and it looks like there's some actionable feedback in the earlier comments.

[webknjaz]

Let's restructure this as follows

Suggested change

	matches = list(
	filter(
	lambda m: m.group("type") == name,
	re.finditer(INLINE_SCRIPT_METADATA_REGEX, script),
	)
	)
	if len(matches) > 1:
	raise ValueError(f"Multiple {name} blocks found")
	elif len(matches) == 1:
	content = "".join(
	line[2:] if line.startswith("# ") else line[1:]
	for line in matches[0]
	.group("content")
	.splitlines(keepends=True)
	)
	metadata = tomllib.loads(content)
	reqs_str = metadata.get("dependencies", [])
	tmpfile = tempfile.NamedTemporaryFile(mode="wt", delete=False)
	input_reqs = "\n".join(reqs_str)
	comes_from = (
	f"{os.path.basename(src_file)} (inline script metadata)"
	)
	else:
	raise PipToolsError(
	"Input script does not contain valid inline script metadata!"
	)
	script_metadata_matches = list(
	filter(
	lambda m: m.group("type") == name,
	re.finditer(INLINE_SCRIPT_METADATA_REGEX, script),
	)
	)
	if not script_metadata_matches:
	raise PipToolsError(
	"Input script does not contain valid inline script metadata!"
	)
	if len(script_metadata_matches) > 1:
	raise ValueError(f"Multiple {name} blocks found")
	script_metadata_match = script_metadata_matches[0]
	packaging_metadata_toml = "".join(
	line[2:] if line.startswith("# ") else line[1:]
	for line in script_metadata_match
	.group("content")
	.splitlines(keepends=True)
	)
	metadata = tomllib.loads(packaging_metadata_toml)
	reqs_str = metadata.get("dependencies", [])
	tmpfile = tempfile.NamedTemporaryFile(mode="wt", delete=False)
	input_reqs = "\n".join(reqs_str)
	comes_from = (
	f"{os.path.basename(src_file)} (inline script metadata)"
	)