Merge pull request #289 from krassowski/fix-and-test-black-tidy-imports

Fix tidy-imports failure when black is used and `pyproject.toml` is missing

lib/python/pyflyby/_importstmt.py

@@ -25,9 +25,9 @@ def read_black_config():
 
 
     """
-    value = find_pyproject_toml('.')
+    pyproject_path = find_pyproject_toml('.')
 
-    raw_config = parse_pyproject_toml(value)
+    raw_config = parse_pyproject_toml(pyproject_path) if pyproject_path else {}
 
     config = {}
     for key in [
@@ -46,7 +46,7 @@ def read_black_config():
             config["target_version"] = set(target_version)
         else:
             raise ValueError(
-                f"Invalid config for black = {target_version!r} in {value}"
+                f"Invalid config for black = {target_version!r} in {pyproject_path}"
             )
     return config
 

tests/test_importstmt.py

@@ -4,10 +4,13 @@
 # http://creativecommons.org/publicdomain/zero/1.0/
 
 
+from   pytest                   import raises
+from   unittest.mock            import patch
 
 from   pyflyby._flags           import CompilerFlags
-from   pyflyby._importstmt      import Import, ImportSplit, ImportStatement
-
+from   pyflyby._format          import FormatParams
+from   pyflyby._importstmt      import (Import, ImportSplit, ImportStatement,
+                                        read_black_config)
 
 def test_Import_from_parts_1():
     imp = Import.from_parts(".foo.bar", "bar")
@@ -118,6 +121,13 @@ def test_Import_replace_2():
     assert result == Import('from xx import yy as bb')
 
 
+@patch("pyflyby._importstmt.read_black_config", lambda: {"line_length": 20})
+def test_Import_black_line_length():
+    stmt = Import("from a123456789 import b123456789")
+    result = stmt.pretty_print(params=FormatParams(use_black=True))
+    assert result == "from a123456789 import (\n    b123456789,\n)\n"
+
+
 def test_ImportStatement_1():
     stmt = ImportStatement("import  foo . bar")
     assert stmt.fromname == None
@@ -206,3 +216,58 @@ def test_ImportStatement_eqne_2():
     assert not (stmt1a != stmt1b)
     assert     (stmt1a != stmt2 )
     assert not (stmt1a == stmt2 )
+
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: None)
+def test_ImportStatement_pretty_print_black_no_config():
+    # running should not error out when no pyproject.toml file is found
+    stmt = ImportStatement("from a import b")
+    result = stmt.pretty_print(params=FormatParams(use_black=True))
+    assert isinstance(result, str)
+
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: None)
+def test_read_black_config_no_config():
+    # reading black config should work when no pyproject.toml file is found
+    config = read_black_config()
+    assert config == {}
+
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: "pyproject.toml")
+@patch(
+    "pyflyby._importstmt.parse_pyproject_toml",
+    lambda path: {
+        "line_length": 80,
+        "skip_magic_trailing_comma": True,
+        "skip_string_normalization": False,
+        "skip_source_first_line": True
+    }
+)
+def test_read_black_config_extracts_config_subset():
+    config = read_black_config()
+    # should copy the desired black options
+    assert config["line_length"] == 80
+    assert config["skip_magic_trailing_comma"] == True
+    assert config["skip_string_normalization"] == False
+    # should not copy anything else
+    assert "skip_source_first_line" not in config
+
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: "pyproject.toml")
+@patch("pyflyby._importstmt.parse_pyproject_toml", lambda path: {"target_version": ["py310", "py311"]})
+def test_read_black_config_target_version_list():
+    config = read_black_config()
+    assert config["target_version"] == {"py310", "py311"}
+
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: "pyproject.toml")
+@patch("pyflyby._importstmt.parse_pyproject_toml", lambda path: {"target_version": "py311"})
+def test_read_black_config_target_version_str():
+    config = read_black_config()
+    assert config["target_version"] == "py311"
+
+@patch("pyflyby._importstmt.find_pyproject_toml", lambda root: "pyproject.toml")
+@patch("pyflyby._importstmt.parse_pyproject_toml", lambda path: {"target_version": object()})
+def test_read_black_config_target_version_other():
+    with raises(ValueError, match="Invalid config for black"):
+        read_black_config()