Render tabs as 4 spaces in diagnostics

crates/ruff/src/message/text.rs

@@ -8,7 +8,8 @@ use bitflags::bitflags;
 use colored::Colorize;
 use ruff_diagnostics::DiagnosticKind;
 use ruff_python_ast::source_code::{OneIndexed, SourceLocation};
-use ruff_text_size::TextRange;
+use ruff_text_size::{TextRange, TextSize};
+use std::borrow::Cow;
 use std::fmt::{Display, Formatter};
 use std::io::Write;
 
@@ -172,6 +173,7 @@ impl Display for MessageCodeFrame<'_> {
         };
 
         let source_code = file.to_source_code();
+
         let content_start_index = source_code.line_index(range.start());
         let mut start_index = content_start_index.saturating_sub(2);
 
@@ -200,26 +202,23 @@ impl Display for MessageCodeFrame<'_> {
         let start_offset = source_code.line_start(start_index);
         let end_offset = source_code.line_end(end_index);
 
-        let source_text = source_code.slice(TextRange::new(start_offset, end_offset));
-
-        let annotation_start_offset = range.start() - start_offset;
-        let annotation_end_offset = range.end() - start_offset;
+        let source = replace_whitespace(
+            source_code.slice(TextRange::new(start_offset, end_offset)),
+            range - start_offset,
+        );
 
-        let start_char = source_text[TextRange::up_to(annotation_start_offset)]
+        let start_char = source.text[TextRange::up_to(source.annotation_range.start())]
             .chars()
             .count();
 
-        let char_length = source_text
-            [TextRange::new(annotation_start_offset, annotation_end_offset)]
-        .chars()
-        .count();
+        let char_length = source.text[source.annotation_range].chars().count();
 
         let label = kind.rule().noqa_code().to_string();
 
         let snippet = Snippet {
             title: None,
             slices: vec![Slice {
-                source: source_text,
+                source: &source.text,
                 line_start: content_start_index.get(),
                 annotations: vec![SourceAnnotation {
                     label: &label,
@@ -245,6 +244,43 @@ impl Display for MessageCodeFrame<'_> {
     }
 }
 
+fn replace_whitespace(source: &str, annotation_range: TextRange) -> SourceCode {
+    let mut result = String::new();
+    let mut last_end = 0;
+    let mut range = annotation_range;
+
+    for (index, _) in source.match_indices('\t') {
+        if index < usize::from(annotation_range.start()) {
+            range += TextSize::new(3);
+        } else if index < usize::from(annotation_range.end()) {
+            range = range.add_end(TextSize::new(3));
+        }
+
+        result.push_str(&source[last_end..index]);
+        result.push_str("    ");
+        last_end = index + 1;
+    }
+
+    // No tabs
+    if result.is_empty() {
+        SourceCode {
+            annotation_range,
+            text: Cow::Borrowed(source),
+        }
+    } else {
+        result.push_str(&source[last_end..]);
+        SourceCode {
+            annotation_range: range,
+            text: Cow::Owned(result),
+        }
+    }
+}
+
+struct SourceCode<'a> {
+    text: Cow<'a, str>,
+    annotation_range: TextRange,
+}
+
 #[cfg(test)]
 mod tests {
     use crate::message::tests::{capture_emitter_output, create_messages};

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E101_E101.py.snap

@@ -5,8 +5,8 @@ E101.py:11:1: E101 Indentation contains mixed spaces and tabs
    |
 11 | def func_mixed_start_with_tab():
 12 |     # E101
-13 | 	  print("mixed starts with tab")
-   | ^^ E101
+13 |       print("mixed starts with tab")
+   | ^^^^^^ E101
 14 | 
 15 | def func_mixed_start_with_space():
    |
@@ -15,8 +15,8 @@ E101.py:15:1: E101 Indentation contains mixed spaces and tabs
    |
 15 | def func_mixed_start_with_space():
 16 |     # E101
-17 |  	  	  	   print("mixed starts with space")
-   | ^^^^^^^^ E101
+17 |                     print("mixed starts with space")
+   | ^^^^^^^^^^^^^^^^^^^^ E101
 18 | 
 19 | def xyz():
    |
@@ -25,8 +25,8 @@ E101.py:19:1: E101 Indentation contains mixed spaces and tabs
    |
 19 | def xyz():
 20 |     # E101
-21 |    	print("xyz");
-   | ^^^ E101
+21 |        print("xyz");
+   | ^^^^^^^ E101
    |
 
 

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E117_E11.py.snap

@@ -25,8 +25,8 @@ E11.py:42:1: E117 Over-indented
    |
 42 | #: E117 W191
 43 | def start():
-44 | 		print()
-   |  E117
+44 |         print()
+   | ^^^^^^^^ E117
    |
 
 

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E201_E20.py.snap

@@ -27,34 +27,34 @@ E20.py:6:15: E201 Whitespace after '('
  8 | spam(ham[1], { eggs: 2})
    |                E201
  9 | #: E201:1:6
-10 | spam(	ham[1], {eggs: 2})
+10 | spam(    ham[1], {eggs: 2})
    |
 
 E20.py:8:6: E201 Whitespace after '('
    |
  8 | spam(ham[1], { eggs: 2})
  9 | #: E201:1:6
-10 | spam(	ham[1], {eggs: 2})
+10 | spam(    ham[1], {eggs: 2})
    |       E201
 11 | #: E201:1:10
-12 | spam(ham[	1], {eggs: 2})
+12 | spam(ham[    1], {eggs: 2})
    |
 
 E20.py:10:10: E201 Whitespace after '('
    |
-10 | spam(	ham[1], {eggs: 2})
+10 | spam(    ham[1], {eggs: 2})
 11 | #: E201:1:10
-12 | spam(ham[	1], {eggs: 2})
+12 | spam(ham[    1], {eggs: 2})
    |           E201
 13 | #: E201:1:15
-14 | spam(ham[1], {	eggs: 2})
+14 | spam(ham[1], {    eggs: 2})
    |
 
 E20.py:12:15: E201 Whitespace after '('
    |
-12 | spam(ham[	1], {eggs: 2})
+12 | spam(ham[    1], {eggs: 2})
 13 | #: E201:1:15
-14 | spam(ham[1], {	eggs: 2})
+14 | spam(ham[1], {    eggs: 2})
    |                E201
 15 | #: Okay
 16 | spam(ham[1], {eggs: 2})

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E202_E20.py.snap

@@ -27,34 +27,34 @@ E20.py:23:11: E202 Whitespace before ')'
 25 | spam(ham[1 ], {eggs: 2})
    |            E202
 26 | #: E202:1:23
-27 | spam(ham[1], {eggs: 2}	)
+27 | spam(ham[1], {eggs: 2}    )
    |
 
 E20.py:25:23: E202 Whitespace before ')'
    |
 25 | spam(ham[1 ], {eggs: 2})
 26 | #: E202:1:23
-27 | spam(ham[1], {eggs: 2}	)
+27 | spam(ham[1], {eggs: 2}    )
    |                        E202
 28 | #: E202:1:22
-29 | spam(ham[1], {eggs: 2	})
+29 | spam(ham[1], {eggs: 2    })
    |
 
 E20.py:27:22: E202 Whitespace before ')'
    |
-27 | spam(ham[1], {eggs: 2}	)
+27 | spam(ham[1], {eggs: 2}    )
 28 | #: E202:1:22
-29 | spam(ham[1], {eggs: 2	})
+29 | spam(ham[1], {eggs: 2    })
    |                       E202
 30 | #: E202:1:11
-31 | spam(ham[1	], {eggs: 2})
+31 | spam(ham[1    ], {eggs: 2})
    |
 
 E20.py:29:11: E202 Whitespace before ')'
    |
-29 | spam(ham[1], {eggs: 2	})
+29 | spam(ham[1], {eggs: 2    })
 30 | #: E202:1:11
-31 | spam(ham[1	], {eggs: 2})
+31 | spam(ham[1    ], {eggs: 2})
    |            E202
 32 | #: Okay
 33 | spam(ham[1], {eggs: 2})

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E203_E20.py.snap

@@ -14,7 +14,7 @@ E20.py:55:10: E203 Whitespace before ',', ';', or ':'
    |
 55 |     x, y = y, x
 56 | #: E203:1:10
-57 | if x == 4	:
+57 | if x == 4    :
    |           E203
 58 |     print x, y
 59 |     x, y = y, x
@@ -34,7 +34,7 @@ E20.py:63:15: E203 Whitespace before ',', ';', or ':'
    |
 63 | #: E203:2:15 E702:2:16
 64 | if x == 4:
-65 |     print x, y	; x, y = y, x
+65 |     print x, y    ; x, y = y, x
    |                E203
 66 | #: E203:3:13
 67 | if x == 4:
@@ -54,7 +54,7 @@ E20.py:71:13: E203 Whitespace before ',', ';', or ':'
    |
 71 | if x == 4:
 72 |     print x, y
-73 |     x, y = y	, x
+73 |     x, y = y    , x
    |              E203
 74 | #: Okay
 75 | if x == 4:

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E223_E22.py.snap

@@ -5,7 +5,7 @@ E22.py:43:2: E223 Tab before operator
    |
 43 | #: E223
 44 | foobart = 4
-45 | a	= 3  # aligned with tab
+45 | a    = 3  # aligned with tab
    |   E223
 46 | #:
    |

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E224_E22.py.snap

@@ -4,7 +4,7 @@ source: crates/ruff/src/rules/pycodestyle/mod.rs
 E22.py:48:5: E224 Tab after operator
    |
 48 | #: E224
-49 | a +=	1
+49 | a +=    1
    |      E224
 50 | b += 1000
 51 | #:

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E271_E27.py.snap

@@ -28,12 +28,12 @@ E27.py:8:3: E271 Multiple spaces after keyword
 10 | if   1:
    |    E271
 11 | #: E273
-12 | True and		False
+12 | True and        False
    |
 
 E27.py:14:6: E271 Multiple spaces after keyword
    |
-14 | True		and	False
+14 | True        and    False
 15 | #: E271
 16 | a and  b
    |       E271

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E272_E27.py.snap

@@ -28,7 +28,7 @@ E27.py:24:5: E272 Multiple spaces before keyword
 26 | this  and False
    |      E272
 27 | #: E273
-28 | a and	b
+28 | a and    b
    |
 
 

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E273_E27.py.snap

@@ -5,28 +5,28 @@ E27.py:10:9: E273 Tab after keyword
    |
 10 | if   1:
 11 | #: E273
-12 | True and		False
+12 | True and        False
    |          E273
 13 | #: E273 E274
-14 | True		and	False
+14 | True        and    False
    |
 
 E27.py:12:5: E273 Tab after keyword
    |
-12 | True and		False
+12 | True and        False
 13 | #: E273 E274
-14 | True		and	False
+14 | True        and    False
    |      E273
 15 | #: E271
 16 | a and  b
    |
 
 E27.py:12:10: E273 Tab after keyword
    |
-12 | True and		False
+12 | True and        False
 13 | #: E273 E274
-14 | True		and	False
-   |         E273
+14 | True        and    False
+   |                 E273
 15 | #: E271
 16 | a and  b
    |
@@ -35,18 +35,18 @@ E27.py:26:6: E273 Tab after keyword
    |
 26 | this  and False
 27 | #: E273
-28 | a and	b
+28 | a and    b
    |       E273
 29 | #: E274
-30 | a		and b
+30 | a        and b
    |
 
 E27.py:30:10: E273 Tab after keyword
    |
-30 | a		and b
+30 | a        and b
 31 | #: E273 E274
-32 | this		and	False
-   |         E273
+32 | this        and    False
+   |                 E273
 33 | #: Okay
 34 | from u import (a, b)
    |

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E274_E27.py.snap

@@ -3,20 +3,20 @@ source: crates/ruff/src/rules/pycodestyle/mod.rs
 ---
 E27.py:28:3: E274 Tab before keyword
    |
-28 | a and	b
+28 | a and    b
 29 | #: E274
-30 | a		and b
-   |   E274
+30 | a        and b
+   |       E274
 31 | #: E273 E274
-32 | this		and	False
+32 | this        and    False
    |
 
 E27.py:30:6: E274 Tab before keyword
    |
-30 | a		and b
+30 | a        and b
 31 | #: E273 E274
-32 | this		and	False
-   |      E274
+32 | this        and    False
+   |          E274
 33 | #: Okay
 34 | from u import (a, b)
    |