Disallow newlines in format specifiers of sinlge quoted f- or t-strings

Author: MichaReiser

crates/ruff_python_formatter/resources/test/fixtures/black/cases/pep_701.py

@@ -74,8 +74,7 @@
 f'{(abc:=10)}'
 
 f"This is a really long string, but just make sure that you reflow fstrings {
-    2+2:d
-}"
+    2+2:d}"
 f"This is a really long string, but just make sure that you reflow fstrings correctly {2+2:d}"
 
 f"{2+2=}"

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/fstring.py

@@ -282,16 +282,7 @@
 
 # Combine conversion flags with format specifiers
 x = f"{x   =   !  s
-         :>0
-
-         }"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = f"{x  !s
-         :>0
-         # comment 21
-         }"
+         :>0}"
 
 x = f"{
     x!s:>{
@@ -315,14 +306,14 @@
         """
 
 # Mix of various features.
-f"{  # comment 26
+f"""{  # comment 26
     foo # after foo
    :>{
           x # after x
           }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 
 f"""{foo
@@ -336,8 +327,7 @@
 f"{
     # comment 31
     foo
-   :>
-}"
+   :>}"
 
 # Assignment statement
 
@@ -491,13 +481,11 @@
 
 # This is not a multiline f-string even though it has a newline after the format specifier.
 aaaaaaaaaaaaaaaaaa = f"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 
 aaaaaaaaaaaaaaaaaa = (
     f"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 )
 
 # The newline is only considered when it's a tripled-quoted f-string.

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/tstring.py

@@ -278,16 +278,7 @@
 
 # Combine conversion flags with format specifiers
 x = t"{x   =   !  s
-         :>0
-
-         }"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = t"{x  !s
-         :>0
-         # comment 21
-         }"
+         :>0}"
 
 x = f"{
     x!s:>{
@@ -310,14 +301,14 @@
         """
 
 # Mix of various features.
-t"{  # comment 26
+t"""{  # comment 26
     foo # after foo
    :>{
           x # after x
           }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 # Assignment statement
 
@@ -471,13 +462,11 @@
 
 # This is not a multiline t-string even though it has a newline after the format specifier.
 aaaaaaaaaaaaaaaaaa = t"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 
 aaaaaaaaaaaaaaaaaa = (
     t"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 )
 
 # The newline is only considered when it's a tripled-quoted t-string.

crates/ruff_python_formatter/src/other/interpolated_string_element.rs

@@ -7,7 +7,7 @@ use ruff_python_ast::{
 };
 use ruff_text_size::{Ranged, TextSlice};
 
-use crate::comments::{dangling_open_parenthesis_comments, trailing_comments};
+use crate::comments::dangling_open_parenthesis_comments;
 use crate::context::{
     InterpolatedStringState, NodeLevel, WithInterpolatedStringState, WithNodeLevel,
 };
@@ -214,31 +214,6 @@ impl Format<PyFormatContext<'_>> for FormatInterpolatedElement<'_> {
                     }
                 }
 
-                // These trailing comments can only occur if the format specifier is
-                // present. For example,
-                //
-                // ```python
-                // f"{
-                //    x:.3f
-                //    # comment
-                // }"
-                // ```
-
-                // This can also be triggered outside of a format spec, at
-                // least until https://github.com/astral-sh/ruff/issues/18632 is a syntax error
-                // TODO(https://github.com/astral-sh/ruff/issues/18632) Remove this
-                //   and double check if it is still necessary for the triple quoted case
-                //   once this is a syntax error.
-                // ```py
-                // f"{
-                //     foo
-                //    :{x}
-                //     # comment 28
-                // } woah {x}"
-                // ```
-                // Any other trailing comments are attached to the expression itself.
-                trailing_comments(comments.trailing(self.element)).fmt(f)?;
-
                 if conversion.is_none() && format_spec.is_none() {
                     bracket_spacing.fmt(f)?;
                 } else if comments.has_trailing_own_line(self.element) {

crates/ruff_python_formatter/tests/fixtures.rs

@@ -324,7 +324,12 @@ fn format_file(source: &str, options: &PyFormatOptions, input_path: &Path) -> St
 
         (Cow::Owned(without_markers), content)
     } else {
-        let printed = format_module_source(source, options.clone()).expect("Formatting to succeed");
+        let printed = format_module_source(source, options.clone()).unwrap_or_else(|err| {
+            panic!(
+                "Formatting of `{input_path} to succeed but it failed: {err}",
+                input_path = input_path.display()
+            )
+        });
         let formatted_code = printed.into_code();
 
         ensure_stability_when_formatting_twice(&formatted_code, options, input_path);

crates/ruff_python_formatter/tests/snapshots/black_compatibility@cases__pep_701.py.snap

@@ -81,8 +81,7 @@ x = f"a{2+2:=^{foo(x+y**2):something else}one more}b"
 f'{(abc:=10)}'
 
 f"This is a really long string, but just make sure that you reflow fstrings {
-    2+2:d
-}"
+    2+2:d}"
 f"This is a really long string, but just make sure that you reflow fstrings correctly {2+2:d}"
 
 f"{2+2=}"

crates/ruff_python_formatter/tests/snapshots/format@expression__fstring.py.snap

@@ -288,16 +288,7 @@ x = f"aaaaaaaaa { x   = !  r  }"
 
 # Combine conversion flags with format specifiers
 x = f"{x   =   !  s
-         :>0
-
-         }"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = f"{x  !s
-         :>0
-         # comment 21
-         }"
+         :>0}"
 
 x = f"{
     x!s:>{
@@ -321,14 +312,14 @@ x = f"""{"foo " +    # comment 24
         """
 
 # Mix of various features.
-f"{  # comment 26
+f"""{  # comment 26
     foo # after foo
    :>{
           x # after x
           }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 
 f"""{foo
@@ -342,8 +333,7 @@ f"""{foo
 f"{
     # comment 31
     foo
-   :>
-}"
+   :>}"
 
 # Assignment statement
 
@@ -497,13 +487,11 @@ aaaaa[aaaaaaaaaaa] = (
 
 # This is not a multiline f-string even though it has a newline after the format specifier.
 aaaaaaaaaaaaaaaaaa = f"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 
 aaaaaaaaaaaaaaaaaa = (
     f"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 )
 
 # The newline is only considered when it's a tripled-quoted f-string.
@@ -1079,13 +1067,6 @@ x = f"aaaaaaaaa { x   = !r}"
 
 # Combine conversion flags with format specifiers
 x = f"{x   =   !s:>0}"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = f"{
-    x!s:>0
-    # comment 21
-}"
 
 x = f"{
     x!s:>{
@@ -1110,13 +1091,13 @@ x = f"""{
         """
 
 # Mix of various features.
-f"{  # comment 26
+f"""{  # comment 26
     foo:>{  # after foo
         x  # after x
     }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 
 f"""{
@@ -1907,13 +1888,6 @@ x = f"aaaaaaaaa { x   = !r}"
 
 # Combine conversion flags with format specifiers
 x = f"{x   =   !s:>0}"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = f"{
-    x!s:>0
-    # comment 21
-}"
 
 x = f"{
     x!s:>{
@@ -1938,13 +1912,13 @@ x = f"""{
         """
 
 # Mix of various features.
-f"{  # comment 26
+f"""{  # comment 26
     foo:>{  # after foo
         x  # after x
     }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 
 f"""{

crates/ruff_python_formatter/tests/snapshots/format@expression__tstring.py.snap

@@ -284,16 +284,7 @@ x = t"aaaaaaaaa { x   = !  r  }"
 
 # Combine conversion flags with format specifiers
 x = t"{x   =   !  s
-         :>0
-
-         }"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = t"{x  !s
-         :>0
-         # comment 21
-         }"
+         :>0}"
 
 x = f"{
     x!s:>{
@@ -316,14 +307,14 @@ x = t"""{"foo " +    # comment 24
         """
 
 # Mix of various features.
-t"{  # comment 26
+t"""{  # comment 26
     foo # after foo
    :>{
           x # after x
           }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 # Assignment statement
 
@@ -477,13 +468,11 @@ aaaaa[aaaaaaaaaaa] = (
 
 # This is not a multiline t-string even though it has a newline after the format specifier.
 aaaaaaaaaaaaaaaaaa = t"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 
 aaaaaaaaaaaaaaaaaa = (
     t"testeeeeeeeeeeeeeeeeeeeeeeeee{
-    a:.3f
-    }moreeeeeeeeeeeeeeeeeetest"  # comment
+    a:.3f}moreeeeeeeeeeeeeeeeeetest"  # comment
 )
 
 # The newline is only considered when it's a tripled-quoted t-string.
@@ -1053,13 +1042,6 @@ x = t"aaaaaaaaa { x   = !r}"
 
 # Combine conversion flags with format specifiers
 x = t"{x   =   !s:>0}"
-# This is interesting. There can be a comment after the format specifier but only if it's
-# on it's own line. Refer to https://github.com/astral-sh/ruff/pull/7787 for more details.
-# We'll format is as trailing comments.
-x = t"{
-    x!s:>0
-    # comment 21
-}"
 
 x = f"{
     x!s:>{
@@ -1083,13 +1065,13 @@ x = t"""{
         """
 
 # Mix of various features.
-t"{  # comment 26
+t"""{  # comment 26
     foo:>{  # after foo
         x  # after x
     }
     # comment 27
     # comment 28
-} woah {x}"
+} woah {x}"""
 
 # Assignment statement