Fix issue #1061

3 files changed, 21 insertions, 8 deletions

diff --git a/isort/main.py b/isort/main.py
index 18c4d164..dfd09873 100644
--- a/isort/main.py
+++ b/isort/main.py
@@ -296,13 +296,6 @@ def parse_args(argv: Optional[Sequence[str]] = None) -> Dict[str, Any]:
         action="store_true",
         help="Turns off default behavior that removes direct imports when as imports exist.",
     )
-    parser.add_argument(
-        "-l",
-        "--lines",
-        help="[Deprecated] The max length of an import line (used for wrapping " "long imports).",
-        dest="line_length",
-        type=int,
-    )
     parser.add_argument("-lai", "--lines-after-imports", dest="lines_after_imports", type=int)
     parser.add_argument("-lbt", "--lines-between-types", dest="lines_between_types", type=int)
     parser.add_argument(
@@ -481,7 +474,9 @@ def parse_args(argv: Optional[Sequence[str]] = None) -> Dict[str, Any]:
         help="Returns just the current version number without the logo",
     )
     parser.add_argument(
+        "-l",
         "-w",
+        "--line-length",
         "--line-width",
         help="The max length of an import line (used for wrapping long imports).",
         dest="line_length",
@@ -492,7 +487,8 @@ def parse_args(argv: Optional[Sequence[str]] = None) -> Dict[str, Any]:
         "--wrap-length",
         dest="wrap_length",
         type=int,
-        help="Specifies how long lines that are wrapped should be, if not set line_length is used.",
+        help="Specifies how long lines that are wrapped should be, if not set line_length is used."
+        "\nNOTE: wrap_length must be LOWER than or equal to line_length.",
     )
     parser.add_argument(
         "--ws",
diff --git a/isort/settings.py b/isort/settings.py
index 387d10e4..04b488f1 100644
--- a/isort/settings.py
+++ b/isort/settings.py
@@ -208,6 +208,11 @@ class _Config:
             object.__setattr__(self, "no_sections", True)
             object.__setattr__(self, "lines_between_types", 1)
             object.__setattr__(self, "from_first", True)
+        if self.wrap_length > self.line_length:
+            raise ValueError(
+                "wrap_length must be set lower than or equal to line_length: "
+                f"{self.wrap_length} > {self.line_length}."
+            )
 
 
 _DEFAULT_SETTINGS = {**vars(_Config()), "source": "defaults"}
diff --git a/tests/test_isort.py b/tests/test_isort.py
index db982587..9e7bcb35 100644
--- a/tests/test_isort.py
+++ b/tests/test_isort.py
@@ -196,6 +196,18 @@ def test_line_length() -> None:
         "                         lib22)\n"
     )
 
+    test_input = (
+        "from .test import a_very_long_function_name_that_exceeds_the_normal_pep8_line_length\n"
+    )
+    with pytest.raises(ValueError):
+        test_output = SortImports(
+            file_contents=REALLY_LONG_IMPORT, line_length=80, wrap_length=99
+        ).output
+    test_output = (
+        SortImports(file_contents=REALLY_LONG_IMPORT, line_length=100, wrap_length=99).output
+        == test_input
+    )
+
 
 def test_output_modes() -> None:
     """Test setting isort to use various output modes works as expected"""