cli.utils.formatter: respect max file name length

src/streamlink_cli/utils/formatter.py

@@ -2,17 +2,18 @@ from pathlib import Path
 from typing import Optional
 
 from streamlink.utils.formatter import Formatter as _BaseFormatter
-from streamlink_cli.utils.path import replace_chars, replace_path
+from streamlink_cli.utils.path import replace_chars, replace_path, truncate_path
 
 
 class Formatter(_BaseFormatter):
     title = _BaseFormatter.format
 
-    def path(self, pathlike: str, charmap: Optional[str] = None) -> Path:
+    def path(self, pathlike: str, charmap: Optional[str] = None, max_filename_length: int = 255) -> Path:
         def mapper(s):
             return replace_chars(s, charmap)
 
-        def format_part(part):
-            return self._format(part, mapper, {})
+        def format_part(part: str, isfile: bool) -> str:
+            formatted = self._format(part, mapper, {})
+            return truncate_path(formatted, max_filename_length, keep_extension=isfile)
 
         return replace_path(pathlike, format_part)

src/streamlink_cli/utils/path.py

@@ -57,9 +57,12 @@ def truncate_path(path: str, length: int = 255, keep_extension: bool = True) ->
     return f"{decoded}.{parts[1]}"
 
 
-def replace_path(pathlike: Union[str, Path], mapper: Callable[[str], str]) -> Path:
-    def get_part(part):
-        newpart = mapper(part)
+def replace_path(pathlike: Union[str, Path], mapper: Callable[[str, bool], str]) -> Path:
+    def get_part(part: str, isfile: bool) -> str:
+        newpart = mapper(part, isfile)
         return REPLACEMENT if part != newpart and newpart in SPECIAL_PATH_PARTS else newpart
 
-    return Path(*(get_part(part) for part in Path(pathlike).expanduser().parts))
+    parts = Path(pathlike).expanduser().parts
+    last = len(parts) - 1
+
+    return Path(*(get_part(part, i == last) for i, part in enumerate(parts)))

tests/cli/utils/test_formatter.py

@@ -1,6 +1,7 @@
 from datetime import datetime
 from os.path import sep
 from pathlib import Path
+from string import ascii_letters as alphabet
 from unittest.mock import Mock, call, patch
 
 import pytest
@@ -79,3 +80,19 @@ class TestCLIFormatter:
         path = formatter.path(f"{{current}}{sep}{{parent}}{sep}{{dots}}{sep}{{separator}}{sep}foo{sep}.{sep}..{sep}bar")
         assert path == Path("_", "_", "...", "_", "foo", ".", "..", "bar"), \
             "Formats the path's parts separately and ignores current and parent directories in substitutions only"
+
+    def test_path_truncation_ascii(self, formatter: Formatter):
+        formatter.mapping.update({
+            "dir": lambda: alphabet * 10,
+            "file": lambda: alphabet * 10,
+        })
+        path = formatter.path(f"{{dir}}.fakeext{sep}{{file}}.ext")
+        assert path == Path((alphabet * 10)[:255], f"{(alphabet * 10)[:251]}.ext")
+
+    def test_path_truncation_unicode(self, formatter: Formatter):
+        formatter.mapping.update({
+            "dir": lambda: "🐻" * 512,
+            "file": lambda: "🐻" * 512,
+        })
+        path = formatter.path(f"{{dir}}.fakeext{sep}{{file}}.ext")
+        assert path == Path("🐻" * 63, f"{'🐻' * 62}.ext")

tests/cli/utils/test_path.py

@@ -59,7 +59,7 @@ def test_replace_chars_replacement():
 
 
 def test_replace_path():
-    def mapper(s):
+    def mapper(s, *_):
         return dict(foo=".", bar="..").get(s, s)
 
     path = Path("foo", ".", "bar", "..", "baz")
@@ -70,15 +70,15 @@ def test_replace_path():
 @pytest.mark.posix_only()
 @pytest.mark.parametrize("os_environ", [pytest.param({"HOME": "/home/foo"}, id="posix")], indirect=True)
 def test_replace_path_expanduser_posix(os_environ):
-    assert replace_path("~/bar", lambda s: s) == Path("/home/foo/bar")
-    assert replace_path("foo/bar", lambda s: dict(foo="~").get(s, s)) == Path("~/bar")
+    assert replace_path("~/bar", lambda s, *_: s) == Path("/home/foo/bar")
+    assert replace_path("foo/bar", lambda s, *_: dict(foo="~").get(s, s)) == Path("~/bar")
 
 
 @pytest.mark.windows_only()
 @pytest.mark.parametrize("os_environ", [pytest.param({"USERPROFILE": "C:\\Users\\foo"}, id="windows")], indirect=True)
 def test_replace_path_expanduser_windows(os_environ):
-    assert replace_path("~\\bar", lambda s: s) == Path("C:\\Users\\foo\\bar")
-    assert replace_path("foo\\bar", lambda s: dict(foo="~").get(s, s)) == Path("~\\bar")
+    assert replace_path("~\\bar", lambda s, *_: s) == Path("C:\\Users\\foo\\bar")
+    assert replace_path("foo\\bar", lambda s, *_: dict(foo="~").get(s, s)) == Path("~\\bar")
 
 
 text = alphabet * 10