Fixed #1290: Unecessary blank lines above nested imports when import …

…comments turned on.
PyCQA · Jul 8, 2020 · a35e464 · a35e464
1 parent bff46f3
commit a35e464
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Showing 3 changed files with 59 additions and 24 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,7 @@ NOTE: isort follows the [semver](https://semver.org/) versioning standard.
   - Fixed #1284: Regression when sorting `.pyi` files from CLI using black profile.
   - Fixed #1275 & #1283: Blank line after docstring removed.
   - Fixed #1298: CLI Help out of date with isort 5.
+  - Fixed #1290: Unecessary blank lines above nested imports when import comments turned on.
 
 ### 5.0.4 July 6, 2020
   - Fixed #1264: a regression with comment handling and `force_sort_within_sections` config option

diff --git a/isort/api.py b/isort/api.py
@@ -560,31 +560,32 @@ def _sort_imports(
                         extension,
                         import_type="cimport" if cimports else "import",
                     )
-                    if indent:
-                        sorted_import_section = (
-                            leading_whitespace
-                            + textwrap.indent(sorted_import_section, indent).strip()
-                            + trailing_whitespace
-                        )
-
-                    if not made_changes:
-                        if config.ignore_whitespace:
-                            compare_in = remove_whitespace(
-                                raw_import_section, line_separator=line_separator
-                            ).strip()
-                            compare_out = remove_whitespace(
-                                sorted_import_section, line_separator=line_separator
-                            ).strip()
-                        else:
-                            compare_in = raw_import_section.strip()
-                            compare_out = sorted_import_section.strip()
-
-                        if compare_out != compare_in:
-                            made_changes = True
+                    if not (import_section.strip() and not sorted_import_section):
+                        if indent:
+                            sorted_import_section = (
+                                leading_whitespace
+                                + textwrap.indent(sorted_import_section, indent).strip()
+                                + trailing_whitespace
+                            )
 
-                    output_stream.write(sorted_import_section)
-                    if not line and not indent and next_import_section:
-                        output_stream.write(line_separator)
+                        if not made_changes:
+                            if config.ignore_whitespace:
+                                compare_in = remove_whitespace(
+                                    raw_import_section, line_separator=line_separator
+                                ).strip()
+                                compare_out = remove_whitespace(
+                                    sorted_import_section, line_separator=line_separator
+                                ).strip()
+                            else:
+                                compare_in = raw_import_section.strip()
+                                compare_out = sorted_import_section.strip()
+
+                            if compare_out != compare_in:
+                                made_changes = True
+
+                        output_stream.write(sorted_import_section)
+                        if not line and not indent and next_import_section:
+                            output_stream.write(line_separator)
 
                 if indent:
                     output_stream.write(line)

diff --git a/tests/test_regressions.py b/tests/test_regressions.py
@@ -61,6 +61,7 @@ def test_blank_lined_removed_issue_1275():
 '''
     )
 
+
 def test_blank_lined_removed_issue_1283():
     """Ensure isort doesn't accidentally remove blank lines after __version__ identifiers.
     See: https://github.com/timothycrosley/isort/issues/1283
@@ -70,3 +71,35 @@ def test_blank_lined_removed_issue_1283():
 from starlette import status
 """
     assert isort.code(test_input) == test_input
+
+
+def test_extra_blank_line_added_nested_imports_issue_1290():
+    """Ensure isort doesn't added unecessary blank lines above nested imports.
+    See: https://github.com/timothycrosley/isort/issues/1290
+    """
+    test_input = '''from typing import TYPE_CHECKING
+
+# Special imports
+from special import thing
+
+if TYPE_CHECKING:
+    # Special imports
+    from special import another_thing
+
+
+def func():
+    """Docstring"""
+
+    # Special imports
+    from special import something_else
+    return
+'''
+    assert (
+        isort.code(
+            test_input,
+            import_heading_special="Special imports",
+            known_special=["special"],
+            sections=["FUTURE", "STDLIB", "THIRDPARTY", "SPECIAL", "FIRSTPARTY", "LOCALFOLDER"],
+        )
+        == test_input
+    )