Support Python 3.8 (#14)

* support Python 3.8

Author: provinzkraut

.github/workflows/CI.yaml

@@ -27,10 +27,11 @@ jobs:
       fail-fast: true
       matrix:
         python-version:
+          - "3.8"
           - "3.9"
           - "3.10"
           - "3.11"
-          - "3.12-dev"
+          - "3.12"
     runs-on: ubuntu-latest
     steps:
       - name: Check out repository

poetry.lock

@@ -7,12 +7,12 @@ license = "MIT"
 readme = "README.md"
 
 [tool.poetry.dependencies]
-python = "^3.9"
+python = "^3.8"
 libcst = "^1.0.0"
 click = "^8.1.7"
-rich = "^13.5.2"
-anyio = "^3.7.0"
-msgspec = "^0.17.0"
+rich = "^13.6.0"
+anyio = "^4.0.0"
+msgspec = "^0.18.4"
 tomli-w = "^1.0.0"
 rich-click = "^1.6.1"
 ruff = {version = "*", optional = true}
@@ -44,7 +44,7 @@ select = [
     "TCH", # flake8-type-checking
     "UP",  # pyupgrade
 ]
-target-version = "py39"
+target-version = "py38"
 
 [tool.mypy]
 strict = true

pyproject.toml

@@ -406,12 +406,12 @@ def test_transform_source_and_target_changed_no_transformation(
     runner: CliRunner, source_file: Path, target_file: Path, mock_transform: MagicMock
 ) -> None:
     args = [f"{source_file}:{target_file}"]
-    result_1 = runner.invoke(main, args)
+    result_1 = runner.invoke(main, args, catch_exceptions=False)
 
     target_file.write_text(TEST_TRANSFORMED_CONTENT + "\n\nimport foo")
     source_file.write_text(TEST_CONTENT + "\n\nimport foo")
 
-    result_2 = runner.invoke(main, args)
+    result_2 = runner.invoke(main, args, catch_exceptions=False)
 
     assert result_1.exit_code == 1
     assert result_2.exit_code == 0
@@ -421,7 +421,11 @@ def test_transform_source_and_target_changed_no_transformation(
 def test_transform_add_editors_note(
     runner: CliRunner, source_file: Path, target_file: Path
 ) -> None:
-    result = runner.invoke(main, [f"{source_file}:{target_file}", "--add-editors-note"])
+    result = runner.invoke(
+        main,
+        [f"{source_file}:{target_file}", "--add-editors-note"],
+        catch_exceptions=False,
+    )
 
     assert result.exit_code == 1
     expected_content = (

test/test_cli.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import time
+from contextlib import nullcontext
 from pathlib import Path
 
 import rich
@@ -20,22 +21,18 @@ async def _run(*, config: Config, check_only: bool, verbose: bool) -> bool:
     files_changed = 0
     files_unchanged = 0
 
-    status = console.status("Processing")
-    if not verbose:
-        status.start()
+    status = console.status("Processing") if not verbose else nullcontext()
+    with status:  # type: ignore[attr-defined]
+        async for result in unasync_files(config=config):
+            if not result.transformed:
+                files_unchanged += 1
+                continue
 
-    async for result in unasync_files(config=config):
-        if not result.transformed:
-            files_unchanged += 1
-            continue
+            files_changed += 1
 
-        files_changed += 1
-
-        verbose_console.print(
-            f"Transformed [yellow]{result.source}[/] > [green]{result.target}[/]"
-        )
-
-    status.stop()
+            verbose_console.print(
+                f"Transformed [yellow]{result.source}[/] > [green]{result.target}[/]"
+            )
 
     console.print(f"Finished in {round(time.perf_counter() - start, 2)} seconds")
     console.print(

unasyncd/cli.py

@@ -7,7 +7,7 @@
 import textwrap
 from concurrent.futures import ProcessPoolExecutor
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Dict
 
 import anyio
 import anyio.to_process
@@ -16,17 +16,96 @@
 from anyio import Path
 
 if TYPE_CHECKING:
-    from collections.abc import AsyncGenerator
+    from collections.abc import AsyncGenerator, Iterator
 
     from .config import Config
 
 
 def _hash_ast(source: str) -> str:
     return hashlib.sha1(
-        ast.unparse(ast.parse(source, type_comments=True)).encode("utf-8")
+        "".join(_stringify_ast(ast.parse(source, type_comments=True))).encode("utf-8")
     ).hexdigest()
 
 
+def _normalize(lineend: str, value: str) -> str:
+    # To normalize, we strip any leading and trailing space from
+    # each line...
+    stripped = [i.strip() for i in value.splitlines()]
+    normalized = lineend.join(stripped)
+    # ...and remove any blank lines at the beginning and end of
+    # the whole string
+    return normalized.strip()
+
+
+def _stringify_ast(node: ast.AST, depth: int = 0) -> Iterator[str]:
+    # this was taken from black
+    # https://github.com/psf/black/blob/ddfecf06c13dd86205c851e340124e325ed82c5c/src/black/parsing.py#L143-L216
+    # and serves as a workaround for generating a hash of an AST, because ast.unparse
+    # is not available until Python 3.9
+    """Simple visitor generating strings to compare ASTs by content."""
+
+    if (
+        isinstance(node, ast.Constant)
+        and isinstance(node.value, str)
+        and node.kind == "u"
+    ):
+        # It's a quirk of history that we strip the u prefix over here. We used to
+        # rewrite the AST nodes for Python version compatibility and we never copied
+        # over the kind
+        node.kind = None
+
+    yield f"{'  ' * depth}{node.__class__.__name__}("
+
+    for field in sorted(node._fields):
+        # TypeIgnore has only one field 'lineno' which breaks this comparison
+        if isinstance(node, ast.TypeIgnore):
+            break
+
+        try:
+            value = getattr(node, field)
+        except AttributeError:
+            continue
+
+        yield f"{'  ' * (depth+1)}{field}="
+
+        if isinstance(value, list):
+            for item in value:
+                # Ignore nested tuples within del statements, because we may insert
+                # parentheses and they change the AST.
+                if (
+                    field == "targets"
+                    and isinstance(node, ast.Delete)
+                    and isinstance(item, ast.Tuple)
+                ):
+                    for elt in item.elts:
+                        yield from _stringify_ast(elt, depth + 2)
+
+                elif isinstance(item, ast.AST):
+                    yield from _stringify_ast(item, depth + 2)
+
+        elif isinstance(value, ast.AST):
+            yield from _stringify_ast(value, depth + 2)
+
+        else:
+            if (
+                isinstance(node, ast.Constant)
+                and field == "value"
+                and isinstance(value, str)
+            ):
+                # Constant strings may be indented across newlines, if they are
+                # docstrings; fold spaces after newlines when comparing. Similarly,
+                # trailing and leading space may be removed.
+                normalized = _normalize("\n", value)
+            elif field == "type_comment" and isinstance(value, str):
+                # Trailing whitespace in type comments is removed.
+                normalized = value.rstrip()
+            else:
+                normalized = value
+            yield f"{'  ' * (depth+2)}{normalized!r},  # {value.__class__.__name__}"
+
+    yield f"{'  ' * depth})  # /{node.__class__.__name__}"
+
+
 @dataclass
 class TransformationResult:
     source: Path
@@ -147,7 +226,7 @@ async def get_meta(self, file: File) -> FileMeta | None:
         """
         if self._meta is None:
             if meta_raw := await self.cache.get("meta.json"):
-                self._meta = msgspec.json.decode(meta_raw, type=dict[str, FileMeta])
+                self._meta = msgspec.json.decode(meta_raw, type=Dict[str, FileMeta])
             else:
                 self._meta = {}