Issue/1499/float to top single line multiline comment

CHANGELOG.md

@@ -12,6 +12,7 @@ Find out more about isort's release policy [here](https://pycqa.github.io/isort/
   - Fixed #1461: Quiet config option not respected by file API in some circumstances.
   - Fixed #1482: pylama integration is not working correctly out-of-the-box.
   - Fixed #1492: --check does not work with stdin source.
+  - Fixed #1499: isort gets confused by single line, multi-line style comments when using float-to-top.
 
 ### 5.5.3 [Hotfix] September 20, 2020
   - Fixed #1488: in rare cases isort can mangle `yield from` or `raise from` statements.

isort/parse.py

@@ -200,12 +200,16 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
         if skipping_line:
             out_lines.append(line)
             continue
-        elif (
+
+        lstripped_line = line.lstrip()
+        if (
             config.float_to_top
             and import_index == -1
             and line
             and not in_quote
-            and not line.strip().startswith("#")
+            and not lstripped_line.startswith("#")
+            and not lstripped_line.startswith("'''")
+            and not lstripped_line.startswith('"""')
         ):
             import_index = index - 1
             while import_index and not in_lines[import_index - 1]:

tests/unit/test_regressions.py

@@ -1081,3 +1081,80 @@ def generator_function():
      from \\
 """
     assert isort.check_code(raise_from_at_file_end_ignored, show_diff=True)
+
+
+def test_isort_float_to_top_correctly_identifies_single_line_comments_1499():
+    """Test to ensure isort correctly handles the case where float to top is used
+    to push imports to the top and the top comment is a multiline type but only
+    one line.
+    See: https://github.com/PyCQA/isort/issues/1499
+    """
+    assert (
+        isort.code(
+            '''#!/bin/bash
+"""My comment"""
+def foo():
+    pass
+
+import a
+
+def bar():
+    pass
+''',
+            float_to_top=True,
+        )
+        == (
+            '''#!/bin/bash
+"""My comment"""
+import a
+
+
+def foo():
+    pass
+
+
+def bar():
+    pass
+'''
+        )
+    )
+    assert (
+        isort.code(
+            """#!/bin/bash
+'''My comment'''
+def foo():
+    pass
+
+import a
+
+def bar():
+    pass
+""",
+            float_to_top=True,
+        )
+        == (
+            """#!/bin/bash
+'''My comment'''
+import a
+
+
+def foo():
+    pass
+
+
+def bar():
+    pass
+"""
+        )
+    )
+
+    assert isort.check_code(
+        """#!/bin/bash
+'''My comment'''
+import a
+
+x = 1
+""",
+        float_to_top=True,
+        show_diff=True,
+    )