convert remaining __file__ usage to pathlib

Bug: None
Test: `./run_tests`
Change-Id: Iaaf7b0c8ce388f6e39123b16bf6c71d3a51edd0f
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repohooks/+/565942
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: Raul Rangel <rrangel@google.com>

rh/config_test.py

diff --git a/rh/config_test.py b/rh/config_test.py
index b63a657..a34b889 100755
--- a/rh/config_test.py
+++ b/rh/config_test.py
@@ -17,12 +17,15 @@
 
 import argparse
 import os
+from pathlib import Path
 import re
 import sys
 
 
-REPOTOOLS = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
-REPO_ROOT = os.path.dirname(os.path.dirname(REPOTOOLS))
+THIS_FILE = Path(__file__).resolve()
+THIS_DIR = THIS_FILE.parent
+# This default assumes an Android checkout.
+REPO_ROOT = THIS_DIR.parent.parent.parent
 
 
 def assertEqual(msg, exp, actual):

rh/hooks.py

diff --git a/rh/hooks.py b/rh/hooks.py
index 506feb1..538d6b0 100644
--- a/rh/hooks.py
+++ b/rh/hooks.py
@@ -343,10 +343,10 @@
 
 
 # Where helper programs exist.
-TOOLS_DIR = os.path.realpath(__file__ + "/../../tools")
+TOOLS_DIR = THIS_DIR.parent / "tools"
 
 
-def get_helper_path(tool):
+def get_helper_path(tool: str) -> str:
     """Return the full path to the helper |tool|."""
     return os.path.join(TOOLS_DIR, tool)
 
@@ -1338,13 +1338,13 @@
 TOOL_PATHS = {
     "aidl-format": "aidl-format",
     "alint": "alint",
-    "android-test-mapping-format": os.path.join(
-        TOOLS_DIR, "android_test_mapping_format.py"
+    "android-test-mapping-format": get_helper_path(
+        "android_test_mapping_format.py"
     ),
     "black": "black",
     "bpfmt": "bpfmt",
     "clang-format": "clang-format",
-    "cpplint": os.path.join(TOOLS_DIR, "cpplint.py"),
+    "cpplint": get_helper_path("cpplint.py"),
     "git-clang-format": "git-clang-format",
     "gofmt": "gofmt",
     "google-java-format": "google-java-format",

tools/pylint.py

diff --git a/tools/pylint.py b/tools/pylint.py
index 92b0dd3..ebf9575 100755
--- a/tools/pylint.py
+++ b/tools/pylint.py
@@ -18,6 +18,7 @@
 import argparse
 import errno
 import os
+from pathlib import Path
 import sys
 import subprocess
 from typing import Dict, List, Optional, Set
@@ -31,9 +32,9 @@
 ), f"Python 3.6 or newer is required; found {sys.version}"
 
 
-DEFAULT_PYLINTRC_PATH = os.path.join(
-    os.path.dirname(os.path.realpath(__file__)), "pylintrc"
-)
+THIS_FILE = Path(__file__).resolve()
+THIS_DIR = THIS_FILE.parent
+DEFAULT_PYLINTRC_PATH = str(THIS_DIR / "pylintrc")
 
 
 def run_lint(
@@ -69,9 +70,11 @@
         )
     except OSError as e:
         if e.errno == errno.ENOENT:
-            print(f"{__file__}: unable to run `{cmd[0]}`: {e}", file=sys.stderr)
             print(
-                f"{__file__}: Try installing pylint: sudo apt-get install "
+                f"{THIS_FILE}: unable to run `{cmd[0]}`: {e}", file=sys.stderr
+            )
+            print(
+                f"{THIS_FILE}: Try installing pylint: sudo apt-get install "
                 f"{os.path.basename(cmd[0])}",
                 file=sys.stderr,
             )
@@ -80,7 +83,7 @@
         raise
 
     if result.returncode:
-        print(f"{__file__}: Using pylintrc: {pylintrc}")
+        print(f"{THIS_FILE}: Using pylintrc: {pylintrc}")
         print(result.stdout)
         return False
 
@@ -101,7 +104,7 @@
 
     if not key.startswith(rootdir):
         sys.exit(
-            f"{__file__}: The search directory {key} is outside the "
+            f"{THIS_FILE}: The search directory {key} is outside the "
             f"repo dir {rootdir}"
         )
 
@@ -155,7 +158,7 @@
                 pylintrc_map[rc_dir].add(f)
                 break
         else:
-            sys.exit(f"{__file__}: Failed to map file {f} to a pylintrc file.")
+            sys.exit(f"{THIS_FILE}: Failed to map file {f} to a pylintrc file.")
 
     return pylintrc_map
 
@@ -195,7 +198,7 @@
                 first = False
                 assert os.path.abspath(rc_dir) == os.path.abspath(
                     "."
-                ), f"{__file__}: pylintrc in top dir not first in list"
+                ), f"{THIS_FILE}: pylintrc in top dir not first in list"
                 if not os.path.exists(pylintrc):
                     pylintrc = DEFAULT_PYLINTRC_PATH
             if not run_lint(