diff --git a/src/borg/testsuite/helpers/parseformat_test.py b/src/borg/testsuite/helpers/parseformat_test.py
index 373a9f6a7..a95245caf 100644
--- a/src/borg/testsuite/helpers/parseformat_test.py
+++ b/src/borg/testsuite/helpers/parseformat_test.py
@@ -4,7 +4,7 @@ from datetime import datetime, timezone
 
 import pytest
 
-from ...constants import * # NOQA
+from ...constants import *  # NOQA
 from ...helpers.argparsing import ArgumentTypeError
 from ...helpers.parseformat import (
     bin_to_hex,
@@ -24,7 +24,7 @@ from ...helpers.parseformat import (
     swidth_slice,
     eval_escapes,
     ChunkerParams,
-    FilesCacheMode,
+    FilesCacheMode,  # <--- MUST BE ADDED HERE
 )
 from ...helpers.time import format_timedelta, parse_timestamp
 from ...platformflags import is_win32
@@ -61,11 +61,13 @@ def test_text_to_json(key, value, strict):
     d = text_to_json(key, value)
     value_b = value.encode("utf-8", errors="surrogateescape")
     if strict:
+        # No surrogate escapes; just Unicode text.
         assert key in d
         assert d[key] == value_b.decode("utf-8", errors="strict")
         assert d[key].encode("utf-8", errors="strict") == value_b
-        assert key_b64 not in d
+        assert key_b64 not in d  # Not needed; pure valid Unicode.
     else:
+        # Requires surrogate escapes. The text has replacement characters; Base64 representation is present.
         assert key in d
         assert d[key] == value.encode("utf-8", errors="replace").decode("utf-8", errors="strict")
         assert d[key].encode("utf-8", errors="strict") == value.encode("utf-8", errors="replace")
@@ -89,24 +91,581 @@ class TestLocationWithoutEnv:
             == "Location(proto='ssh', user='user', pass=None, host='host', port=1234, path='/absolute/path')"
         )
         assert Location("ssh://user@host:1234//absolute/path").to_key_filename() == keys_dir + "host___absolute_path"
+        assert (
+            repr(Location("ssh://user@host:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='host', port=1234, path='relative/path')"
+        )
+        assert Location("ssh://user@host:1234/relative/path").to_key_filename() == keys_dir + "host__relative_path"
+        assert (
+            repr(Location("ssh://user@host/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='host', port=None, path='relative/path')"
+        )
+        assert (
+            repr(Location("ssh://user@[::]:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='::', port=1234, path='relative/path')"
+        )
+        assert Location("ssh://user@[::]:1234/relative/path").to_key_filename() == keys_dir + "____relative_path"
+        assert (
+            repr(Location("ssh://user@[::]/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='::', port=None, path='relative/path')"
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::]:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::', port=1234, path='relative/path')"
+        )
+        assert (
+            Location("ssh://user@[2001:db8::]:1234/relative/path").to_key_filename()
+            == keys_dir + "2001_db8____relative_path"
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::]/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::', port=None, path='relative/path')"
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::c0:ffee]:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::c0:ffee', port=1234, path='relative/path')"  # noqa: E501
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::c0:ffee]/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::c0:ffee', port=None, path='relative/path')"  # noqa: E501
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::192.0.2.1]:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::192.0.2.1', port=1234, path='relative/path')"  # noqa: E501
+        )
+        assert (
+            repr(Location("ssh://user@[2001:db8::192.0.2.1]/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='2001:db8::192.0.2.1', port=None, path='relative/path')"  # noqa: E501
+        )
+        assert (
+            Location("ssh://user@[2001:db8::192.0.2.1]/relative/path").to_key_filename()
+            == keys_dir + "2001_db8__192_0_2_1__relative_path"
+        )
+        assert (
+            repr(Location("ssh://user@[2a02:0001:0002:0003:0004:0005:0006:0007]/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, "
+            "host='2a02:0001:0002:0003:0004:0005:0006:0007', port=None, path='relative/path')"
+        )
+        assert (
+            repr(Location("ssh://user@[2a02:0001:0002:0003:0004:0005:0006:0007]:1234/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, "
+            "host='2a02:0001:0002:0003:0004:0005:0006:0007', port=1234, path='relative/path')"
+        )
+
+    def test_s3(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("s3:/test/path"))
+            == "Location(proto='s3', user=None, pass=None, host=None, port=None, path='test/path')"
+        )
+        assert (
+            repr(Location("s3:profile@http://172.28.52.116:9000/test/path"))
+            == "Location(proto='s3', user='profile', pass=None, host='172.28.52.116', port=9000, path='test/path')"  # noqa: E501
+        )
+        assert (
+            repr(Location("s3:user:pass@http://172.28.52.116:9000/test/path"))
+            == "Location(proto='s3', user='user', pass='REDACTED', host='172.28.52.116', port=9000, path='test/path')"  # noqa: E501
+        )
+        assert (
+            repr(Location("b2:user:pass@https://s3.us-east-005.backblazeb2.com/test/path"))
+            == "Location(proto='b2', user='user', pass='REDACTED', host='s3.us-east-005.backblazeb2.com', port=None, path='test/path')"  # noqa: E501
+        )
+
+    def test_rclone(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("rclone:remote:path"))
+            == "Location(proto='rclone', user=None, pass=None, host=None, port=None, path='remote:path')"
+        )
+        assert Location("rclone:remote:path").to_key_filename() == keys_dir + "remote_path"
+
+    def test_sftp(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        # relative path
+        assert (
+            repr(Location("sftp://user@host:1234/rel/path"))
+            == "Location(proto='sftp', user='user', pass=None, host='host', port=1234, path='rel/path')"
+        )
+        assert Location("sftp://user@host:1234/rel/path").to_key_filename() == keys_dir + "host__rel_path"
+        # absolute path
+        assert (
+            repr(Location("sftp://user@host:1234//abs/path"))
+            == "Location(proto='sftp', user='user', pass=None, host='host', port=1234, path='/abs/path')"
+        )
+        assert Location("sftp://user@host:1234//abs/path").to_key_filename() == keys_dir + "host___abs_path"
+
+    def test_http(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("http://user:pass@host:1234/"))
+            == "Location(proto='http', user='user', pass='REDACTED', host='host', port=1234, path='/')"
+        )
+        assert Location("http://user:pass@host:1234/").to_key_filename() == keys_dir + "host__"
+
+    def test_socket(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        url = "socket:///c:/repo/path" if is_win32 else "socket:///repo/path"
+        path = "c:/repo/path" if is_win32 else "/repo/path"
+        assert (
+            repr(Location(url))
+            == f"Location(proto='socket', user=None, pass=None, host=None, port=None, path='{path}')"
+        )
+        assert Location(url).to_key_filename().endswith("_repo_path")
+
+    def test_file(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        url = "file:///c:/repo/path" if is_win32 else "file:///repo/path"
+        path = "c:/repo/path" if is_win32 else "/repo/path"
+        assert (
+            repr(Location(url)) == f"Location(proto='file', user=None, pass=None, host=None, port=None, path='{path}')"
+        )
+        assert Location(url).to_key_filename().endswith("_repo_path")
+
+    @pytest.mark.skipif(is_win32, reason="still broken")
+    def test_smb(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("file:////server/share/path"))
+            == "Location(proto='file', user=None, pass=None, host=None, port=None, path='//server/share/path')"
+        )
+        assert Location("file:////server/share/path").to_key_filename().endswith("__server_share_path")
+
+    def test_folder(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        rel_path = "path"
+        abs_path = os.path.abspath(rel_path)
+        assert (
+            repr(Location(rel_path))
+            == f"Location(proto='file', user=None, pass=None, host=None, port=None, path='{abs_path}')"
+        )
+        assert Location("path").to_key_filename().endswith(rel_path)
+
+    @pytest.mark.skipif(is_win32, reason="Windows has drive letters in abs paths")
+    def test_abspath(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("/some/absolute/path"))
+            == "Location(proto='file', user=None, pass=None, host=None, port=None, path='/some/absolute/path')"
+        )
+        assert Location("/some/absolute/path").to_key_filename() == keys_dir + "_some_absolute_path"
+        assert (
+            repr(Location("/some/../absolute/path"))
+            == "Location(proto='file', user=None, pass=None, host=None, port=None, path='/absolute/path')"
+        )
+        assert Location("/some/../absolute/path").to_key_filename() == keys_dir + "_absolute_path"
+
+    def test_relpath(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        # For a local path, Borg creates a Location instance with an absolute path.
+        rel_path = "relative/path"
+        abs_path = os.path.abspath(rel_path)
+        assert (
+            repr(Location(rel_path))
+            == f"Location(proto='file', user=None, pass=None, host=None, port=None, path='{abs_path}')"
+        )
+        assert Location(rel_path).to_key_filename().endswith("relative_path")
+        assert (
+            repr(Location("ssh://user@host/relative/path"))
+            == "Location(proto='ssh', user='user', pass=None, host='host', port=None, path='relative/path')"
+        )
+        assert Location("ssh://user@host/relative/path").to_key_filename() == keys_dir + "host__relative_path"
+
+    @pytest.mark.skipif(is_win32, reason="Windows does not support colons in paths")
+    def test_with_colons(self, monkeypatch, keys_dir):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        assert (
+            repr(Location("/abs/path:w:cols"))
+            == "Location(proto='file', user=None, pass=None, host=None, port=None, path='/abs/path:w:cols')"
+        )
+        assert Location("/abs/path:w:cols").to_key_filename() == keys_dir + "_abs_path_w_cols"
+        assert (
+            repr(Location("file:///abs/path:w:cols"))
+            == "Location(proto='file', user=None, pass=None, host=None, port=None, path='/abs/path:w:cols')"
+        )
+        assert Location("file:///abs/path:w:cols").to_key_filename() == keys_dir + "_abs_path_w_cols"
+        assert (
+            repr(Location("ssh://user@host/abs/path:w:cols"))
+            == "Location(proto='ssh', user='user', pass=None, host='host', port=None, path='abs/path:w:cols')"
+        )
+        assert Location("ssh://user@host/abs/path:w:cols").to_key_filename() == keys_dir + "host__abs_path_w_cols"
+
+    def test_canonical_path(self, monkeypatch):
+        monkeypatch.delenv("BORG_REPO", raising=False)
+        locations = [
+            "relative/path",
+            "ssh://host/relative/path",
+            "ssh://host//absolute/path",
+            "ssh://user@host:1234/relative/path",
+            "sftp://host/relative/path",
+            "sftp://host//absolute/path",
+            "sftp://user@host:1234/relative/path",
+            "rclone:remote:path",
+        ]
+        locations.insert(1, "c:/absolute/path" if is_win32 else "/absolute/path")
+        locations.insert(2, "file:///c:/absolute/path" if is_win32 else "file:///absolute/path")
+        locations.insert(3, "socket:///c:/absolute/path" if is_win32 else "socket:///absolute/path")
+        for location in locations:
+            assert (
+                Location(location).canonical_path() == Location(Location(location).canonical_path()).canonical_path()
+            ), ("failed: %s" % location)
 
     def test_bad_syntax(self):
         with pytest.raises(ValueError):
+            # This is invalid due to the second colon. Correct: 'ssh://user@host/path'.
             Location("ssh://user@host:/path")
 
 
-def test_archivename_ok(name="foobar"):
+@pytest.mark.parametrize(
+    "name",
+    [
+        "foobar",
+        # Placeholders
+        "foobar-{now}",
+    ],
+)
+def test_archivename_ok(name):
     assert archivename_validator(name) == name
 
 
+@pytest.mark.parametrize(
+    "name",
+    [
+        "",  # too short
+        "x" * 201,  # too long
+        # Invalid characters:
+        "foo/bar",
+        "foo\\bar",
+        ">foo",
+        "<foo",
+        "|foo",
+        'foo"bar',
+        "foo?",
+        "*bar",
+        "foo\nbar",
+        "foo\0bar",
+        # Leading/trailing blanks
+        " foo",
+        "bar  ",
+        # Contains surrogate escapes
+        "foo\udc80bar",
+        "foo\udcffbar",
+    ],
+)
+def test_archivename_invalid(name):
+    with pytest.raises(ArgumentTypeError):
+        archivename_validator(name)
+
+
+@pytest.mark.parametrize("text", ["", "single line", "multi\nline\ncomment"])
+def test_text_ok(text):
+    assert text_validator(name="text", max_length=100)(text) == text
+
+
+@pytest.mark.parametrize(
+    "text",
+    [
+        "x" * 101,  # too long
+        # Invalid characters:
+        "foo\0bar",
+        # Contains surrogate escapes
+        "foo\udc80bar",
+        "foo\udcffbar",
+    ],
+)
+def test_text_invalid(text):
+    invalid_ctrl_chars = "".join(chr(i) for i in range(32))
+    tv = text_validator(name="text", max_length=100, min_length=1, invalid_ctrl_chars=invalid_ctrl_chars)
+    with pytest.raises(ArgumentTypeError):
+        tv(text)
+
+
+def test_format_timedelta():
+    t0 = datetime(2001, 1, 1, 10, 20, 3, 0)
+    t1 = datetime(2001, 1, 1, 12, 20, 4, 100000)
+    assert format_timedelta(t1 - t0) == "2 hours 1.100 seconds"
+
+
+@pytest.mark.parametrize(
+    "timeframe, num_secs",
+    [
+        ("5S", 5),
+        ("2M", 2 * 60),
+        ("1H", 60 * 60),
+        ("1d", 24 * 60 * 60),
+        ("1w", 7 * 24 * 60 * 60),
+        ("1m", 31 * 24 * 60 * 60),
+        ("1y", 365 * 24 * 60 * 60),
+    ],
+)
+def test_interval(timeframe, num_secs):
+    assert interval(timeframe) == num_secs
+
+
+@pytest.mark.parametrize(
+    "invalid_interval, error_tuple",
+    [
+        ("H", ('Invalid number "": expected positive integer',)),
+        ("-1d", ('Invalid number "-1": expected positive integer',)),
+        ("food", ('Invalid number "foo": expected positive integer',)),
+    ],
+)
+def test_interval_time_unit(invalid_interval, error_tuple):
+    with pytest.raises(ArgumentTypeError) as exc:
+        interval(invalid_interval)
+    assert exc.value.args == error_tuple
+
+
+def test_interval_number():
+    with pytest.raises(ArgumentTypeError) as exc:
+        interval("5")
+    assert exc.value.args == ('Unexpected time unit "5": choose from y, m, w, d, H, M, S',)
+
+
+def test_parse_timestamp():
+    assert parse_timestamp("2015-04-19T20:25:00.226410") == datetime(2015, 4, 19, 20, 25, 0, 226410, timezone.utc)
+    assert parse_timestamp("2015-04-19T20:25:00") == datetime(2015, 4, 19, 20, 25, 0, 0, timezone.utc)
+
+
+@pytest.mark.parametrize(
+    "size, fmt",
+    [
+        (0, "0 B"),  # No rounding necessary for these.
+        (1, "1 B"),
+        (142, "142 B"),
+        (999, "999 B"),
+        (1000, "1.00 kB"),  # rounding starts here
+        (1001, "1.00 kB"),  # should be rounded away
+        (1234, "1.23 kB"),  # should be rounded down
+        (1235, "1.24 kB"),  # should be rounded up
+        (1010, "1.01 kB"),  # rounded down as well
+        (999990000, "999.99 MB"),  # rounded down
+        (999990001, "999.99 MB"),  # rounded down
+        (999995000, "1.00 GB"),  # Rounded up to the next unit.
+        (10**6, "1.00 MB"),  # and all the remaining units, megabytes
+        (10**9, "1.00 GB"),  # gigabytes
+        (10**12, "1.00 TB"),  # terabytes
+        (10**15, "1.00 PB"),  # petabytes
+        (10**18, "1.00 EB"),  # exabytes
+        (10**21, "1.00 ZB"),  # zottabytes
+        (10**24, "1.00 YB"),  # yottabytes
+        (-1, "-1 B"),  # negative value
+        (-1010, "-1.01 kB"),  # negative value with rounding
+    ],
+)
+def test_file_size(size, fmt):
+    """test the size formatting routines"""
+    assert format_file_size(size) == fmt
+
+
+@pytest.mark.parametrize(
+    "size, fmt",
+    [
+        (0, "0 B"),
+        (2**0, "1 B"),
+        (2**10, "1.00 KiB"),
+        (2**20, "1.00 MiB"),
+        (2**30, "1.00 GiB"),
+        (2**40, "1.00 TiB"),
+        (2**50, "1.00 PiB"),
+        (2**60, "1.00 EiB"),
+        (2**70, "1.00 ZiB"),
+        (2**80, "1.00 YiB"),
+        (-(2**0), "-1 B"),
+        (-(2**10), "-1.00 KiB"),
+        (-(2**20), "-1.00 MiB"),
+    ],
+)
+def test_file_size_iec(size, fmt):
+    """test the size formatting routines"""
+    assert format_file_size(size, iec=True) == fmt
+
+
+@pytest.mark.parametrize(
+    "original_size, formatted_size",
+    [
+        (1234, "1.2 kB"),  # rounded down
+        (1254, "1.3 kB"),  # rounded up
+        (999990000, "1.0 GB"),  # and not 999.9 MB or 1000.0 MB
+    ],
+)
+def test_file_size_precision(original_size, formatted_size):
+    assert format_file_size(original_size, precision=1) == formatted_size
+
+
+@pytest.mark.parametrize("size, fmt", [(0, "0 B"), (1, "+1 B"), (1234, "+1.23 kB"), (-1, "-1 B"), (-1234, "-1.23 kB")])
+def test_file_size_sign(size, fmt):
+    assert format_file_size(size, sign=True) == fmt
+
+
+@pytest.mark.parametrize(
+    "string, value", [("1", 1), ("20", 20), ("5K", 5000), ("1.75M", 1750000), ("1e+9", 1e9), ("-1T", -1e12)]
+)
+def test_parse_file_size(string, value):
+    assert parse_file_size(string) == int(value)
+
+
+@pytest.mark.parametrize("string", ("", "5 Äpfel", "4E", "2229 bit", "1B"))
+def test_parse_file_size_invalid(string):
+    with pytest.raises(ValueError):
+        parse_file_size(string)
+
+
+@pytest.mark.parametrize(
+    "fmt, items_map, expected_result",
+    [
+        ("{space:10}", {"space": " "}, " " * 10),
+        ("{foobar}", {"bar": "wrong", "foobar": "correct"}, "correct"),
+        ("{unknown_key}", {}, "{unknown_key}"),
+        ("{key}{{escaped_key}}", {}, "{key}{{escaped_key}}"),
+        ("{{escaped_key}}", {"escaped_key": 1234}, "{{escaped_key}}"),
+    ],
+)
+def test_partial_format(fmt, items_map, expected_result):
+    assert partial_format(fmt, items_map) == expected_result
+
+
+def test_clean_lines():
+    conf = """\
+#comment
+data1 #data1
+data2
+
+ data3
+""".splitlines(keepends=True)
+    assert list(clean_lines(conf)) == ["data1 #data1", "data2", "data3"]
+    assert list(clean_lines(conf, lstrip=False)) == ["data1 #data1", "data2", " data3"]
+    assert list(clean_lines(conf, rstrip=False)) == ["data1 #data1\n", "data2\n", "data3\n"]
+    assert list(clean_lines(conf, remove_empty=False)) == ["data1 #data1", "data2", "", "data3"]
+    assert list(clean_lines(conf, remove_comments=False)) == ["#comment", "data1 #data1", "data2", "data3"]
+
+
+def test_format_line():
+    data = dict(foo="bar baz")
+    assert format_line("", data) == ""
+    assert format_line("{foo}", data) == "bar baz"
+    assert format_line("foo{foo}foo", data) == "foobar bazfoo"
+
+
+def test_format_line_erroneous():
+    data = dict()
+    with pytest.raises(PlaceholderError):
+        assert format_line("{invalid}", data)
+    with pytest.raises(PlaceholderError):
+        assert format_line("{}", data)
+    with pytest.raises(PlaceholderError):
+        assert format_line("{now!r}", data)
+    with pytest.raises(PlaceholderError):
+        assert format_line("{now.__class__.__module__.__builtins__}", data)
+
+
+def test_replace_placeholders():
+    replace_placeholders.reset()  # avoid overrides are spoiled by previous tests
+    now = datetime.now()
+    assert " " not in replace_placeholders("{now}")
+    assert int(replace_placeholders("{now:%Y}")) == now.year
+
+
+def test_override_placeholders():
+    assert replace_placeholders("{uuid4}", overrides={"uuid4": "overridden"}) == "overridden"
+
+
+def working_swidth():
+    from ...platform import swidth
+
+    return swidth("선") == 2
+
+
+@pytest.mark.skipif(not working_swidth(), reason="swidth() is not supported / active")
+def test_swidth_slice():
+    string = "나윤선나윤선나윤선나윤선나윤선"
+    assert swidth_slice(string, 1) == ""
+    assert swidth_slice(string, -1) == ""
+    assert swidth_slice(string, 4) == "나윤"
+    assert swidth_slice(string, -4) == "윤선"
+
+
+@pytest.mark.skipif(not working_swidth(), reason="swidth() is not supported / active")
+def test_swidth_slice_mixed_characters():
+    string = "나윤a선나윤선나윤선나윤선나윤선"
+    assert swidth_slice(string, 5) == "나윤a"
+    assert swidth_slice(string, 6) == "나윤a"
+
+
+def test_eval_escapes():
+    assert eval_escapes("\\n") == "\n"
+    assert eval_escapes("\\t") == "\t"
+    assert eval_escapes("\\r") == "\r"
+    assert eval_escapes("\\f") == "\f"
+    assert eval_escapes("\\b") == "\b"
+    assert eval_escapes("\\a") == "\a"
+    assert eval_escapes("\\v") == "\v"
+    assert eval_escapes("\\\\") == "\\"
+    assert eval_escapes('\\"') == '"'
+    assert eval_escapes("\\'") == "'"
+    assert eval_escapes("\\101") == "A"  # ord('A') == 65 == 0o101
+    assert eval_escapes("\\x41") == "A"  # ord('A') == 65 == 0x41
+    assert eval_escapes("\\u0041") == "A"  # ord('A') == 65 == 0x41
+    assert eval_escapes("\\U00000041") == "A"  # ord('A') == 65 == 0x41
+    assert eval_escapes("äç\\n") == "äç\n"
+
+
+@pytest.mark.parametrize(
+    "chunker_params, expected_return",
+    [
+        ("default", ("buzhash", 19, 23, 21, 4095)),
+        ("19,23,21,4095", ("buzhash", 19, 23, 21, 4095)),
+        ("buzhash,19,23,21,4095", ("buzhash", 19, 23, 21, 4095)),
+        ("10,23,16,4095", ("buzhash", 10, 23, 16, 4095)),
+        ("fixed,4096", ("fixed", 4096, 0)),
+        ("fixed,4096,200", ("fixed", 4096, 200)),
+    ],
+)
+def test_valid_chunkerparams(chunker_params, expected_return):
+    assert ChunkerParams(chunker_params) == expected_return
+
+
+@pytest.mark.parametrize(
+    "invalid_chunker_params",
+    [
+        "crap,1,2,3,4",  # invalid algo
+        "buzhash,5,7,6,4095",  # too small min. size
+        "buzhash,19,24,21,4095",  # too big max. size
+        "buzhash,23,19,21,4095",  # violates min <= mask <= max
+        "buzhash,19,23,21,4096",  # even window size
+        "fixed,63",  # too small block size
+        "fixed,%d,%d" % (MAX_DATA_SIZE + 1, 4096),  # too big block size
+        "fixed,%d,%d" % (4096, MAX_DATA_SIZE + 1),  # too big header size
+    ],
+)
+def test_invalid_chunkerparams(invalid_chunker_params):
+    with pytest.raises(ArgumentTypeError):
+        ChunkerParams(invalid_chunker_params)
+
+
 def test_files_cache_mode_win32_restriction(monkeypatch):
     from borg.helpers import parseformat
+    from borg.helpers.parseformat import FilesCacheMode, ArgumentTypeError
+    import pytest
 
+    # 1. Simulate being on a Windows system
     monkeypatch.setattr(parseformat, "is_win32", True)
+
+    # 2. Test that 'cis' (contains ctime) raises the error
     with pytest.raises(ArgumentTypeError, match="ctime is not supported"):
         FilesCacheMode("cis")
+
+    # 3. Test that comma-separated 'ctime,size' also raises the error
     with pytest.raises(ArgumentTypeError, match="ctime is not supported"):
         FilesCacheMode("ctime,size")
+
+    # 4. Ensure a non-ctime mode still works on 'Windows'
     assert FilesCacheMode("ims") == "ims"
+
+    # 5. Switch back to non-Windows and ensure 'cis' works again
     monkeypatch.setattr(parseformat, "is_win32", False)
-    assert FilesCacheMode("cis") == "cis"
\ No newline at end of file
+    assert FilesCacheMode("cis") == "cis"
+
+
+def test_new_placeholder():
+    # Simple test for a helper function like eval_escapes
+    assert eval_escapes(r"hello\nworld") == "hello\nworld"