scripts/diff_shades_gha_helper.py - third_party/github.com/psf/black - Git at Google

 """Helper script for psf/black's diff-shades Github Actions integration.

 diff-shades is a tool for analyzing what happens when you run Black on
 OSS code capturing it for comparisons or other usage. It's used here to
 help measure the impact of a change *before* landing it (in particular
 posting a comment on completion for PRs).

 This script exists as a more maintainable alternative to using inline
 Javascript in the workflow YAML files. The revision configuration and
 resolving, caching, and PR comment logic is contained here.

 For more information, please see the developer docs:

 https://black.readthedocs.io/en/latest/contributing/gauging_changes.html#diff-shades
 """

 import json
 import os
 import platform
 import pprint
 import subprocess
 import sys
 import zipfile
 from io import BytesIO
 from pathlib import Path
 from typing import Any

 import click
 import urllib3
 from packaging.version import Version

 if sys.version_info >= (3, 8):
     from typing import Final, Literal
 else:
     from typing_extensions import Final, Literal

 COMMENT_FILE: Final = ".pr-comment.json"
 DIFF_STEP_NAME: Final = "Generate HTML diff report"
 DOCS_URL: Final = (
     "https://black.readthedocs.io/en/latest/"
     "contributing/gauging_changes.html#diff-shades"
 )
 USER_AGENT: Final = f"psf/black diff-shades workflow via urllib3/{urllib3.__version__}"
 SHA_LENGTH: Final = 10
 GH_API_TOKEN: Final = os.getenv("GITHUB_TOKEN")
 REPO: Final = os.getenv("GITHUB_REPOSITORY", default="psf/black")
 http = urllib3.PoolManager()


 def set_output(name: str, value: str) -> None:
     if len(value) < 200:
         print(f"[INFO]: setting '{name}' to '{value}'")
     else:
         print(f"[INFO]: setting '{name}' to [{len(value)} chars]")
     print(f"::set-output name={name}::{value}")


 def http_get(url: str, *, is_json: bool = True, **kwargs: Any) -> Any:
     headers = kwargs.get("headers") or {}
     headers["User-Agent"] = USER_AGENT
     if "github" in url:
         if GH_API_TOKEN:
             headers["Authorization"] = f"token {GH_API_TOKEN}"
         headers["Accept"] = "application/vnd.github.v3+json"
     kwargs["headers"] = headers

     r = http.request("GET", url, **kwargs)
     if is_json:
         data = json.loads(r.data.decode("utf-8"))
     else:
         data = r.data
     print(f"[INFO]: issued GET request for {r.geturl()}")
     if not (200 <= r.status < 300):
         pprint.pprint(dict(r.info()))
         pprint.pprint(data)
         raise RuntimeError(f"unexpected status code: {r.status}")

     return data


 def get_main_revision() -> str:
     data = http_get(
         f"https://api.github.com/repos/{REPO}/commits",
         fields={"per_page": "1", "sha": "main"},
     )
     assert isinstance(data[0]["sha"], str)
     return data[0]["sha"]


 def get_pr_revision(pr: int) -> str:
     data = http_get(f"https://api.github.com/repos/{REPO}/pulls/{pr}")
     assert isinstance(data["head"]["sha"], str)
     return data["head"]["sha"]


 def get_pypi_version() -> Version:
     data = http_get("https://pypi.org/pypi/black/json")
     versions = [Version(v) for v in data["releases"]]
     sorted_versions = sorted(versions, reverse=True)
     return sorted_versions[0]


 @click.group()
 def main() -> None:
     pass


 @main.command("config", help="Acquire run configuration and metadata.")
 @click.argument("event", type=click.Choice(["push", "pull_request"]))
 def config(event: Literal["push", "pull_request"]) -> None:
     import diff_shades

     if event == "push":
         jobs = [{"mode": "preview-changes", "force-flag": "--force-preview-style"}]
         # Push on main, let's use PyPI Black as the baseline.
         baseline_name = str(get_pypi_version())
         baseline_cmd = f"git checkout {baseline_name}"
         target_rev = os.getenv("GITHUB_SHA")
         assert target_rev is not None
         target_name = "main-" + target_rev[:SHA_LENGTH]
         target_cmd = f"git checkout {target_rev}"

     elif event == "pull_request":
         jobs = [
             {"mode": "preview-changes", "force-flag": "--force-preview-style"},
             {"mode": "assert-no-changes", "force-flag": "--force-stable-style"},
         ]
         # PR, let's use main as the baseline.
         baseline_rev = get_main_revision()
         baseline_name = "main-" + baseline_rev[:SHA_LENGTH]
         baseline_cmd = f"git checkout {baseline_rev}"
         pr_ref = os.getenv("GITHUB_REF")
         assert pr_ref is not None
         pr_num = int(pr_ref[10:-6])
         pr_rev = get_pr_revision(pr_num)
         target_name = f"pr-{pr_num}-{pr_rev[:SHA_LENGTH]}"
         target_cmd = f"gh pr checkout {pr_num} && git merge origin/main"

     env = f"{platform.system()}-{platform.python_version()}-{diff_shades.__version__}"
     for entry in jobs:
         entry["baseline-analysis"] = f"{entry['mode']}-{baseline_name}.json"
         entry["baseline-setup-cmd"] = baseline_cmd
         entry["target-analysis"] = f"{entry['mode']}-{target_name}.json"
         entry["target-setup-cmd"] = target_cmd
         entry["baseline-cache-key"] = f"{env}-{baseline_name}-{entry['mode']}"
         if event == "pull_request":
             # These are only needed for the PR comment.
             entry["baseline-sha"] = baseline_rev
             entry["target-sha"] = pr_rev

     set_output("matrix", json.dumps(jobs, indent=None))
     pprint.pprint(jobs)


 @main.command("comment-body", help="Generate the body for a summary PR comment.")
 @click.argument("baseline", type=click.Path(exists=True, path_type=Path))
 @click.argument("target", type=click.Path(exists=True, path_type=Path))
 @click.argument("baseline-sha")
 @click.argument("target-sha")
 @click.argument("pr-num", type=int)
 def comment_body(
     baseline: Path, target: Path, baseline_sha: str, target_sha: str, pr_num: int
 ) -> None:
     # fmt: off
     cmd = [
         sys.executable, "-m", "diff_shades", "--no-color",
         "compare", str(baseline), str(target), "--quiet", "--check"
     ]
     # fmt: on
     proc = subprocess.run(cmd, stdout=subprocess.PIPE, encoding="utf-8")
     if not proc.returncode:
         body = (
             f"**diff-shades** reports zero changes comparing this PR ({target_sha}) to"
             f" main ({baseline_sha}).\n\n---\n\n"
         )
     else:
         body = (
             f"**diff-shades** results comparing this PR ({target_sha}) to main"
             f" ({baseline_sha}). The full diff is [available in the logs]"
             f'($job-diff-url) under the "{DIFF_STEP_NAME}" step.'
         )
         body += "\n```text\n" + proc.stdout.strip() + "\n```\n"
     body += (
         f"[**What is this?**]({DOCS_URL}) | [Workflow run]($workflow-run-url) |"
         " [diff-shades documentation](https://github.com/ichard26/diff-shades#readme)"
     )
     print(f"[INFO]: writing comment details to {COMMENT_FILE}")
     with open(COMMENT_FILE, "w", encoding="utf-8") as f:
         json.dump({"body": body, "pr-number": pr_num}, f)


 @main.command("comment-details", help="Get PR comment resources from a workflow run.")
 @click.argument("run-id")
 def comment_details(run_id: str) -> None:
     data = http_get(f"https://api.github.com/repos/{REPO}/actions/runs/{run_id}")
     if data["event"] != "pull_request" or data["conclusion"] == "cancelled":
         set_output("needs-comment", "false")
         return

     set_output("needs-comment", "true")
     jobs = http_get(data["jobs_url"])["jobs"]
     job = next(j for j in jobs if j["name"] == "analysis / preview-changes")
     diff_step = next(s for s in job["steps"] if s["name"] == DIFF_STEP_NAME)
     diff_url = job["html_url"] + f"#step:{diff_step['number']}:1"

     artifacts = http_get(data["artifacts_url"])["artifacts"]
     comment_artifact = next(a for a in artifacts if a["name"] == COMMENT_FILE)
     comment_url = comment_artifact["archive_download_url"]
     comment_zip = BytesIO(http_get(comment_url, is_json=False))
     with zipfile.ZipFile(comment_zip) as zfile:
         with zfile.open(COMMENT_FILE) as rf:
             comment_data = json.loads(rf.read().decode("utf-8"))

     set_output("pr-number", str(comment_data["pr-number"]))
     body = comment_data["body"]
     # It's more convenient to fill in these fields after the first workflow is done
     # since this command can access the workflows API (doing it in the main workflow
     # while it's still in progress seems impossible).
     body = body.replace("$workflow-run-url", data["html_url"])
     body = body.replace("$job-diff-url", diff_url)
     # https://github.community/t/set-output-truncates-multiline-strings/16852/3
     escaped = body.replace("%", "%25").replace("\n", "%0A").replace("\r", "%0D")
     set_output("comment-body", escaped)


 if __name__ == "__main__":
     main()
	"""Helper script for psf/black's diff-shades Github Actions integration.

	diff-shades is a tool for analyzing what happens when you run Black on
	OSS code capturing it for comparisons or other usage. It's used here to
	help measure the impact of a change before landing it (in particular
	posting a comment on completion for PRs).

	This script exists as a more maintainable alternative to using inline
	Javascript in the workflow YAML files. The revision configuration and
	resolving, caching, and PR comment logic is contained here.

	For more information, please see the developer docs:

	https://black.readthedocs.io/en/latest/contributing/gauging_changes.html#diff-shades
	"""

	import json
	import os
	import platform
	import pprint
	import subprocess
	import sys
	import zipfile
	from io import BytesIO
	from pathlib import Path
	from typing import Any

	import click
	import urllib3
	from packaging.version import Version

	if sys.version_info >= (3, 8):
	from typing import Final, Literal
	else:
	from typing_extensions import Final, Literal

	COMMENT_FILE: Final = ".pr-comment.json"
	DIFF_STEP_NAME: Final = "Generate HTML diff report"
	DOCS_URL: Final = (
	"https://black.readthedocs.io/en/latest/"
	"contributing/gauging_changes.html#diff-shades"
	)
	USER_AGENT: Final = f"psf/black diff-shades workflow via urllib3/{urllib3.__version__}"
	SHA_LENGTH: Final = 10
	GH_API_TOKEN: Final = os.getenv("GITHUB_TOKEN")
	REPO: Final = os.getenv("GITHUB_REPOSITORY", default="psf/black")
	http = urllib3.PoolManager()


	def set_output(name: str, value: str) -> None:
	if len(value) < 200:
	print(f"[INFO]: setting '{name}' to '{value}'")
	else:
	print(f"[INFO]: setting '{name}' to [{len(value)} chars]")
	print(f"::set-output name={name}::{value}")


	def http_get(url: str, , is_json: bool = True, *kwargs: Any) -> Any:
	headers = kwargs.get("headers") or {}
	headers["User-Agent"] = USER_AGENT
	if "github" in url:
	if GH_API_TOKEN:
	headers["Authorization"] = f"token {GH_API_TOKEN}"
	headers["Accept"] = "application/vnd.github.v3+json"
	kwargs["headers"] = headers

	r = http.request("GET", url, **kwargs)
	if is_json:
	data = json.loads(r.data.decode("utf-8"))
	else:
	data = r.data
	print(f"[INFO]: issued GET request for {r.geturl()}")
	if not (200 <= r.status < 300):
	pprint.pprint(dict(r.info()))
	pprint.pprint(data)
	raise RuntimeError(f"unexpected status code: {r.status}")

	return data


	def get_main_revision() -> str:
	data = http_get(
	f"https://api.github.com/repos/{REPO}/commits",
	fields={"per_page": "1", "sha": "main"},
	)
	assert isinstance(data[0]["sha"], str)
	return data[0]["sha"]


	def get_pr_revision(pr: int) -> str:
	data = http_get(f"https://api.github.com/repos/{REPO}/pulls/{pr}")
	assert isinstance(data["head"]["sha"], str)
	return data["head"]["sha"]


	def get_pypi_version() -> Version:
	data = http_get("https://pypi.org/pypi/black/json")
	versions = [Version(v) for v in data["releases"]]
	sorted_versions = sorted(versions, reverse=True)
	return sorted_versions[0]


	@click.group()
	def main() -> None:
	pass


	@main.command("config", help="Acquire run configuration and metadata.")
	@click.argument("event", type=click.Choice(["push", "pull_request"]))
	def config(event: Literal["push", "pull_request"]) -> None:
	import diff_shades

	if event == "push":
	jobs = [{"mode": "preview-changes", "force-flag": "--force-preview-style"}]
	# Push on main, let's use PyPI Black as the baseline.
	baseline_name = str(get_pypi_version())
	baseline_cmd = f"git checkout {baseline_name}"
	target_rev = os.getenv("GITHUB_SHA")
	assert target_rev is not None
	target_name = "main-" + target_rev[:SHA_LENGTH]
	target_cmd = f"git checkout {target_rev}"

	elif event == "pull_request":
	jobs = [
	{"mode": "preview-changes", "force-flag": "--force-preview-style"},
	{"mode": "assert-no-changes", "force-flag": "--force-stable-style"},
	]
	# PR, let's use main as the baseline.
	baseline_rev = get_main_revision()
	baseline_name = "main-" + baseline_rev[:SHA_LENGTH]
	baseline_cmd = f"git checkout {baseline_rev}"
	pr_ref = os.getenv("GITHUB_REF")
	assert pr_ref is not None
	pr_num = int(pr_ref[10:-6])
	pr_rev = get_pr_revision(pr_num)
	target_name = f"pr-{pr_num}-{pr_rev[:SHA_LENGTH]}"
	target_cmd = f"gh pr checkout {pr_num} && git merge origin/main"

	env = f"{platform.system()}-{platform.python_version()}-{diff_shades.__version__}"
	for entry in jobs:
	entry["baseline-analysis"] = f"{entry['mode']}-{baseline_name}.json"
	entry["baseline-setup-cmd"] = baseline_cmd
	entry["target-analysis"] = f"{entry['mode']}-{target_name}.json"
	entry["target-setup-cmd"] = target_cmd
	entry["baseline-cache-key"] = f"{env}-{baseline_name}-{entry['mode']}"
	if event == "pull_request":
	# These are only needed for the PR comment.
	entry["baseline-sha"] = baseline_rev
	entry["target-sha"] = pr_rev

	set_output("matrix", json.dumps(jobs, indent=None))
	pprint.pprint(jobs)


	@main.command("comment-body", help="Generate the body for a summary PR comment.")
	@click.argument("baseline", type=click.Path(exists=True, path_type=Path))
	@click.argument("target", type=click.Path(exists=True, path_type=Path))
	@click.argument("baseline-sha")
	@click.argument("target-sha")
	@click.argument("pr-num", type=int)
	def comment_body(
	baseline: Path, target: Path, baseline_sha: str, target_sha: str, pr_num: int
	) -> None:
	# fmt: off
	cmd = [
	sys.executable, "-m", "diff_shades", "--no-color",
	"compare", str(baseline), str(target), "--quiet", "--check"
	]
	# fmt: on
	proc = subprocess.run(cmd, stdout=subprocess.PIPE, encoding="utf-8")
	if not proc.returncode:
	body = (
	f"diff-shades reports zero changes comparing this PR ({target_sha}) to"
	f" main ({baseline_sha}).\n\n---\n\n"
	)
	else:
	body = (
	f"diff-shades results comparing this PR ({target_sha}) to main"
	f" ({baseline_sha}). The full diff is [available in the logs]"
	f'($job-diff-url) under the "{DIFF_STEP_NAME}" step.'
	)
	body += "\n```text\n" + proc.stdout.strip() + "\n```\n"
	body += (
	f"[What is this?]({DOCS_URL}) \| [Workflow run]($workflow-run-url) \|"
	" [diff-shades documentation](https://github.com/ichard26/diff-shades#readme)"
	)
	print(f"[INFO]: writing comment details to {COMMENT_FILE}")
	with open(COMMENT_FILE, "w", encoding="utf-8") as f:
	json.dump({"body": body, "pr-number": pr_num}, f)


	@main.command("comment-details", help="Get PR comment resources from a workflow run.")
	@click.argument("run-id")
	def comment_details(run_id: str) -> None:
	data = http_get(f"https://api.github.com/repos/{REPO}/actions/runs/{run_id}")
	if data["event"] != "pull_request" or data["conclusion"] == "cancelled":
	set_output("needs-comment", "false")
	return

	set_output("needs-comment", "true")
	jobs = http_get(data["jobs_url"])["jobs"]
	job = next(j for j in jobs if j["name"] == "analysis / preview-changes")
	diff_step = next(s for s in job["steps"] if s["name"] == DIFF_STEP_NAME)
	diff_url = job["html_url"] + f"#step:{diff_step['number']}:1"

	artifacts = http_get(data["artifacts_url"])["artifacts"]
	comment_artifact = next(a for a in artifacts if a["name"] == COMMENT_FILE)
	comment_url = comment_artifact["archive_download_url"]
	comment_zip = BytesIO(http_get(comment_url, is_json=False))
	with zipfile.ZipFile(comment_zip) as zfile:
	with zfile.open(COMMENT_FILE) as rf:
	comment_data = json.loads(rf.read().decode("utf-8"))

	set_output("pr-number", str(comment_data["pr-number"]))
	body = comment_data["body"]
	# It's more convenient to fill in these fields after the first workflow is done
	# since this command can access the workflows API (doing it in the main workflow
	# while it's still in progress seems impossible).
	body = body.replace("$workflow-run-url", data["html_url"])
	body = body.replace("$job-diff-url", diff_url)
	# https://github.community/t/set-output-truncates-multiline-strings/16852/3
	escaped = body.replace("%", "%25").replace("\n", "%0A").replace("\r", "%0D")
	set_output("comment-body", escaped)


	if __name__ == "__main__":
	main()