tasks: add lint tasks: lint, format, mypy (#9)

Author: stanislaw

hpdf/hpdf.py

@@ -4,12 +4,11 @@
 import base64
 import os.path
 import sys
-import tempfile
 from datetime import datetime
 from pathlib import Path
 from shutil import copy
 from time import sleep
-from typing import Optional, List
+from typing import Dict, List, Optional
 
 import requests
 from requests import Response
@@ -151,25 +150,28 @@ def get_pdf_from_html(driver, url) -> bytes:
     print("html2pdf: executing print command with ChromeDriver.")  # noqa: T201
     result = driver.execute_cdp_cmd("Page.printToPDF", calculated_print_options)
 
-    class Done(Exception): pass
+    class Done(Exception):
+        pass
 
     datetime_start = datetime.today()
 
-    logs = None
+    logs: List[Dict[str, str]] = []
     try:
         while True:
             logs = driver.get_log("browser")
             for entry_ in logs:
                 if "HTML2PDF4DOC time" in entry_["message"]:
-                    print("success: HTML2PDF completed its job.")
+                    print("success: HTML2PDF completed its job.")  # noqa: T201
                     raise Done
             if (datetime.today() - datetime_start).total_seconds() > 60:
                 raise TimeoutError
             sleep(0.5)
     except Done:
         pass
     except TimeoutError:
-        print("error: could not receive a successful completion status from HTML2PDF.")
+        print(  # noqa: T201
+            "error: could not receive a successful completion status from HTML2PDF."
+        )
         sys.exit(1)
 
     print("html2pdf: JS logs from the print session:")  # noqa: T201
@@ -244,19 +246,15 @@ def main():
         type=str,
         help="Optional path to a cache directory whereto the ChromeDriver is downloaded.",
     )
-    parser.add_argument("paths", nargs='+', help="Paths to input HTML file.")
+    parser.add_argument("paths", nargs="+", help="Paths to input HTML file.")
     args = parser.parse_args()
 
     paths: List[str] = args.paths
 
     path_to_cache_dir: str = (
         args.cache_dir
         if args.cache_dir is not None
-        else (
-            os.path.join(
-                Path.home(), ".hpdf", "chromedriver"
-            )
-        )
+        else (os.path.join(Path.home(), ".hpdf", "chromedriver"))
     )
     driver = create_webdriver(args.chromedriver, path_to_cache_dir)
 
@@ -265,7 +263,9 @@ def exit_handler():
         print("html2pdf: exit handler: quitting the ChromeDriver.")  # noqa: T201
         driver.quit()
 
-    assert len(paths) % 2 == 0, f"Expecting an even number of input/output path arguments: {paths}."
+    assert len(paths) % 2 == 0, (
+        f"Expecting an even number of input/output path arguments: {paths}."
+    )
     for current_pair_idx in range(0, 2, len(paths)):
         path_to_input_html = paths[current_pair_idx]
         path_to_output_pdf = paths[current_pair_idx + 1]

requirements.development.txt

@@ -3,6 +3,12 @@ toml
 packaging
 setuptools
 
+#
+# Lint
+#
+mypy>=0.910
+ruff>=0.9
+
 #
 # Integration tests
 #

ruff.toml

@@ -0,0 +1,103 @@
+target-version = "py38"
+line-length = 80
+
+[lint]
+select = [
+  "A",
+  "ARG",
+  "B",
+  # "BLE",
+  "C",
+  "C4",
+  # "C90"  mccabe
+
+  # Not clear if this check is useful. Too many commas everywhere.
+  # "COM",
+
+  # "D",
+  # "DTZ",
+  # "E",
+  "EXE",
+  "ERA",
+  "F",
+  # "FBT",
+  "G",
+  "I",
+  "ISC",
+  "ICN",
+  # "N",
+  "PGH",
+  # "PIE",
+  "PL",  # Pylint
+  # "PT",  # pytest
+  # "PTH",
+  "Q",  # Quotes
+  # "RET",
+  # "RUF",
+  # "S",
+  # "SIM",
+  # "SLF",
+ "T20",
+  # "TCH",
+  # "TRY",
+  "UP",
+  "W",
+  "YTT",
+]
+
+ignore = [
+    # TBD: Unnecessary `list` comprehension (rewrite using `list()`)
+    "C416",
+    # TBD: Unnecessary `map` usage (rewrite using a `list` comprehension)
+    "C417",
+
+    # X is too complex
+    "C901",
+
+    "E501",  # (line length violations).
+
+    # A warning by ruff format:
+    # warning: The following rules may cause conflicts when used with the formatter: `ISC001`.
+    "ISC001",
+
+    # Too many return statements
+    "PLR0911",
+
+    # Too many branches
+    "PLR0912",
+
+    # Too many arguments in function definition
+    "PLR0913",
+
+    # Too many statements
+    "PLR0915",
+
+    # TBD: Enable: Use `sys.exit()` instead of `exit`
+    "PLR1722",
+
+    # Magic value used in comparison
+    "PLR2004",
+
+    # Use `elif` instead of `else` then `if`, to reduce indentation
+    "PLR5501",
+
+    "UP035", # [*] Import from `collections.abc` instead: `Iterator`
+    "UP038", # [*] Use `X | Y` in `isinstance` call instead of `(X, Y)` (conflict with Pylint)
+]
+
+# Avoid trying to fix flake8-bugbear (`B`) violations.
+unfixable = ["B"]
+
+# Skip non UTF-8 test files
+# exclude = ["tests/**/invalid_file*"]
+
+# B008 Do not perform function calls in argument defaults.
+# The call is performed only once at function definition time.
+
+[lint.per-file-ignores]
+# "foo.py" = ["B008"]
+
+# Some of our helpers have deliberatly the name of a standard library module
+
+[lint.flake8-builtins]
+builtins-allowed-modules = ["math", "pickle", "string"]

tasks.py

@@ -60,21 +60,76 @@ def bootstrap(context):
 
 @task
 def build(context):
-    run_invoke(context, "cd submodules/html2pdf && npm install && npm run build")
+    run_invoke(
+        context, "cd submodules/html2pdf && npm install && npm run build"
+    )
 
 
 @task
 def format_readme(context):
-    run_invoke(context, """
+    run_invoke(
+        context,
+        """
     prettier
         --write --print-width 80 --prose-wrap always --parser=markdown
         README.md
-    """)
+    """,
+    )
 
 
 @task
+def lint_ruff_format(context):
+    result: invoke.runners.Result = run_invoke(
+        context,
+        """
+            ruff
+                format
+                *.py
+                hpdf/
+                tests/integration/
+        """,
+    )
+    # Ruff always exits with 0, so we handle the output.
+    if "reformatted" in result.stdout:
+        print("invoke: ruff format found issues")  # noqa: T201
+        result.exited = 1
+        raise invoke.exceptions.UnexpectedExit(result)
+
+
+@task(aliases=["lr"])
+def lint_ruff(context):
+    run_invoke(
+        context,
+        """
+            ruff check *.py hpdf/ --fix --cache-dir build/ruff
+        """,
+    )
+
+
+@task(aliases=["lm"])
+def lint_mypy(context):
+    # These checks do not seem to be useful:
+    # - import
+    # - misc
+    run_invoke(
+        context,
+        """
+            mypy hpdf/
+                --show-error-codes
+                --disable-error-code=import
+                --disable-error-code=misc
+                --cache-dir=build/mypy
+                --strict
+                --python-version=3.8
+        """,
+    )
+
+
+@task(aliases=["l"])
 def lint(context):
-    pass
+    lint_ruff_format(context)
+    lint_ruff(context)
+    lint_mypy(context)
 
 
 @task

tests/integration/check_exists.py

@@ -56,25 +56,19 @@
 else:
     if os.path.exists(args.input_path):
         print(  # noqa: T201
-            "error: expected path to not exist, but it does: {}".format(
-                args.input_path
-            ),
+            f"error: expected path to not exist, but it does: {args.input_path}",
             file=sys.stderr,
         )
         exit(1)
     if args.file and os.path.isfile(args.input_path):
         print(  # noqa: T201
-            "error: expected path to not exist, but is a file: {}".format(
-                args.input_path
-            ),
+            f"error: expected path to not exist, but is a file: {args.input_path}",
             file=sys.stderr,
         )
         exit(1)
     if args.dir and os.path.isdir(args.input_path):
         print(  # noqa: T201
-            "error: expected path to not exist, but is a directory: {}".format(
-                args.input_path
-            ),
+            f"error: expected path to not exist, but is a directory: {args.input_path}",
             file=sys.stderr,
         )
         exit(1)

tests/integration/expect_exit.py

@@ -51,9 +51,7 @@
 unexpected_exit_code = process.returncode != expected_exit_code
 if unexpected_exit_code:
     print(  # noqa: T201
-        "error: expect_exit: expected exit code: {}, actual: {}".format(
-            expected_exit_code, process.returncode
-        )
+        f"error: expect_exit: expected exit code: {expected_exit_code}, actual: {process.returncode}"
     )
 
 unexpected_content = expect_no_content and len(stdout) > 0