Hug multiline-strings preview style (#9243)

crates/ruff_python_formatter/resources/test/fixtures/ruff/multiline_string_deviations.py

@@ -0,0 +1,43 @@
+# This file documents the deviations for formatting multiline strings with black.
+
+# Black hugs the parentheses for `%` usages -> convert to fstring.
+# Can get unreadable if the arguments split
+# This could be solved by using `best_fitting` to try to format the arguments on a single
+# line. Let's consider adding this later.
+# ```python
+# call(
+#    3,
+#    "dogsay",
+#    textwrap.dedent(
+#        """dove
+#    coo""" % "cowabunga",
+#        more,
+#        and_more,
+#        "aaaaaaa",
+#        "bbbbbbbbb",
+#        "cccccccc",
+#    ),
+# )
+# ```
+call(3, "dogsay", textwrap.dedent("""dove
+    coo""" % "cowabunga"))
+
+# Black applies the hugging recursively. We don't (consistent with the hugging style).
+path.write_text(textwrap.dedent("""\
+    A triple-quoted string
+    actually leveraging the textwrap.dedent functionality
+    that ends in a trailing newline,
+    representing e.g. file contents.
+"""))
+
+
+
+# Black avoids parenthesizing the following lambda. We could potentially support
+# this by changing `Lambda::needs_parentheses` to return `BestFit` but it causes
+# issues when the lambda has comments.
+# Let's keep this as a known deviation for now.
+generated_readme = lambda project_name: """
+{}
+
+<Add content here!>
+""".strip().format(project_name)