Add unit tests for OutputLine

2 files changed, 97 insertions, 5 deletions

diff --git a/pylint/testutils/output_line.py b/pylint/testutils/output_line.py
index a5284e47f..492ce7902 100644
--- a/pylint/testutils/output_line.py
+++ b/pylint/testutils/output_line.py
@@ -36,10 +36,13 @@ class MalformedOutputLineException(Exception):
         ]
         reconstructed_row = ""
         i = 0
-        for i, column in enumerate(row):
-            reconstructed_row += f"\t{expected[i]}='{column}' ?\n"
-        for missing in expected[i + 1 :]:
-            reconstructed_row += f"\t{missing}= Nothing provided !\n"
+        try:
+            for i, column in enumerate(row):
+                reconstructed_row += f"\t{expected[i]}='{column}' ?\n"
+            for missing in expected[i + 1 :]:
+                reconstructed_row += f"\t{missing}= Nothing provided !\n"
+        except IndexError:
+            pass
         raw = ":".join(row)
         msg = f"""\
 {exception}
@@ -73,7 +76,7 @@ class OutputLine(
     @classmethod
     def get_column(cls, column):
         if not PY38_PLUS:
-            return ""
+            return ""  # pragma: no cover
         return str(column)
 
     @classmethod
diff --git a/tests/testutils/test_output_line.py b/tests/testutils/test_output_line.py
new file mode 100644
index 000000000..513d75ee2
--- /dev/null
+++ b/tests/testutils/test_output_line.py
@@ -0,0 +1,89 @@
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/master/LICENSE
+
+# pylint: disable=redefined-outer-name
+
+import pytest
+
+from pylint.interfaces import HIGH
+from pylint.message import Message
+from pylint.testutils.output_line import MalformedOutputLineException, OutputLine
+
+
+@pytest.fixture()
+def message():
+    return Message(
+        symbol="missing-docstring",
+        msg_id="C0123",
+        location=[
+            "abspath",
+            "path",
+            "module",
+            "obj",
+            "line",
+            "column",
+        ],
+        msg="msg",
+        confidence=HIGH,
+    )
+
+
+def test_output_line():
+    output_line = OutputLine(
+        symbol="missing-docstring",
+        lineno=0,
+        column=0,
+        object="",
+        msg="Missing docstring's bad.",
+        confidence=HIGH,
+    )
+    assert output_line.symbol == "missing-docstring"
+
+
+def test_output_line_from_message(message):
+    output_line = OutputLine.from_msg(message)
+    assert output_line.symbol == "missing-docstring"
+    assert output_line.msg == "msg"
+
+
+def test_output_line_to_csv(message):
+    output_line = OutputLine.from_msg(message)
+    csv = output_line.to_csv()
+    assert csv == ("missing-docstring", "line", "column", "obj", "msg")
+
+
+def test_output_line_from_csv_error():
+    with pytest.raises(
+        MalformedOutputLineException,
+        match="msg-symbolic-name:42:27:MyClass.my_function:The message",
+    ):
+        OutputLine.from_csv("'missing-docstring', 'line', 'column', 'obj', 'msg'")
+    with pytest.raises(
+        MalformedOutputLineException, match="symbol='missing-docstring' ?"
+    ):
+        csv = ("missing-docstring", "line", "column", "obj", "msg")
+        OutputLine.from_csv(csv)
+
+
+@pytest.mark.parametrize(
+    "confidence,expected", [[None, "HIGH"], ["INFERENCE", "INFERENCE"]]
+)
+def test_output_line_from_csv(confidence, expected):
+    proper_csv = (
+        "missing-docstring",
+        "1",
+        "2",
+        "obj",
+        "msg",
+    )
+    if confidence is not None:
+        proper_csv += (confidence,)
+    output_line = OutputLine.from_csv(proper_csv)
+    assert output_line == OutputLine(
+        symbol="missing-docstring",
+        lineno=1,
+        column="2",
+        object="obj",
+        msg="msg",
+        confidence=expected,
+    )