1 files changed, 87 insertions, 0 deletions
diff --git a/gitlint-core/gitlint/utils.py b/gitlint-core/gitlint/utils.py
new file mode 100644
index 0000000..3ccb78b
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+++ b/gitlint-core/gitlint/utils.py
@@ -0,0 +1,87 @@
+import codecs
+import locale
+import os
+import platform
+
+# Note: While we can easily inline the logic related to the constants set in this module, we deliberately create
+# small functions that encapsulate that logic as this enables easy unit testing. In particular, by creating functions
+# we can easily mock the dependencies during testing, which is not possible if the code is not enclosed in a function
+# and just executed at import-time.
+
+########################################################################################################################
+LOG_FORMAT = "%(levelname)s: %(name)s %(message)s"
+
+########################################################################################################################
+# PLATFORM_IS_WINDOWS
+
+
+def platform_is_windows():
+    return "windows" in platform.system().lower()
+
+
+PLATFORM_IS_WINDOWS = platform_is_windows()
+
+########################################################################################################################
+# USE_SH_LIB
+# Determine whether to use the `sh` library
+# On windows we won't want to use the sh library since it's not supported - instead we'll use our own shell module.
+# However, we want to be able to overwrite this behavior for testing using the GITLINT_USE_SH_LIB env var.
+
+
+def use_sh_library():
+    gitlint_use_sh_lib_env = os.environ.get("GITLINT_USE_SH_LIB", None)
+    if gitlint_use_sh_lib_env:
+        return gitlint_use_sh_lib_env == "1"
+    return False
+
+
+USE_SH_LIB = use_sh_library()
+
+########################################################################################################################
+# TERMINAL_ENCODING
+# Encoding used for terminal encoding/decoding.
+
+
+def getpreferredencoding():
+    """Modified version of local.getpreferredencoding() that takes into account LC_ALL, LC_CTYPE, LANG env vars
+    on windows and falls back to UTF-8."""
+    fallback_encoding = "UTF-8"
+    preferred_encoding = locale.getpreferredencoding() or fallback_encoding
+
+    # On Windows, we mimic git/linux by trying to read the LC_ALL, LC_CTYPE, LANG env vars manually
+    # (on Linux/MacOS the `getpreferredencoding()` call will take care of this).
+    # We fallback to UTF-8
+    if PLATFORM_IS_WINDOWS:
+        preferred_encoding = fallback_encoding
+        for env_var in ["LC_ALL", "LC_CTYPE", "LANG"]:
+            encoding = os.environ.get(env_var, False)
+            if encoding:
+                # Support dotted (C.UTF-8) and non-dotted (C or UTF-8) charsets:
+                # If encoding contains a dot: split and use second part, otherwise use everything
+                dot_index = encoding.find(".")
+                preferred_encoding = encoding[dot_index + 1 :] if dot_index != -1 else encoding
+                break
+
+        # We've determined what encoding the user *wants*, let's now check if it's actually a valid encoding on the
+        # system. If not, fallback to UTF-8.
+        # This scenario is fairly common on Windows where git sets LC_CTYPE=C when invoking the commit-msg hook, which
+        # is not a valid encoding in Python on Windows.
+        try:
+            codecs.lookup(preferred_encoding)
+        except LookupError:
+            preferred_encoding = fallback_encoding
+
+    return preferred_encoding
+
+
+TERMINAL_ENCODING = getpreferredencoding()
+
+########################################################################################################################
+# FILE_ENCODING
+# Gitlint assumes UTF-8 encoding for all file operations:
+#  - reading/writing its own hook and config files
+#  - reading/writing git commit messages
+# Git does have i18n.commitEncoding and i18n.logOutputEncoding options which we might want to take into account,
+# but that's not supported today.
+
+FILE_ENCODING = "UTF-8"