Implement D206, D207, and D208 (#429)

README.md

@@ -216,12 +216,13 @@ variables.)
 
 ruff also implements some of the most popular Flake8 plugins natively, including:
 
+- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
+- [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/)
 - [`flake8-builtins`](https://pypi.org/project/flake8-builtins/)
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
 - [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/)
 - [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (3/32)
-- [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/) (41/48)
 - [`pyupgrade`](https://pypi.org/project/pyupgrade/) (8/34)
 
 Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis Flake8:
@@ -327,6 +328,9 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | D203 | OneBlankLineBeforeClass | 1 blank line required before class docstring |  |  |
 | D204 | OneBlankLineAfterClass | 1 blank line required after class docstring |  |  |
 | D205 | NoBlankLineAfterSummary | 1 blank line required between summary line and description |  |  |
+| D206 | IndentWithSpaces | Docstring should be indented with spaces, not tabs |  |  |
+| D207 | NoUnderIndentation | Docstring is under-indented |  |  |
+| D208 | NoOverIndentation | Docstring is over-indented |  |  |
 | D209 | NewLineAfterLastParagraph | Multi-line docstring closing quotes should be on a separate line |  |  |
 | D210 | NoSurroundingWhitespace | No whitespaces allowed surrounding docstring text |  |  |
 | D211 | NoBlankLineBeforeClass | No blank lines allowed before class docstring |  |  |

src/check_ast.rs

@@ -1969,6 +1969,12 @@ impl<'a> Checker<'a> {
             if self.settings.enabled.contains(&CheckCode::D205) {
                 docstring_plugins::blank_after_summary(self, &docstring);
             }
+            if self.settings.enabled.contains(&CheckCode::D206)
+                || self.settings.enabled.contains(&CheckCode::D207)
+                || self.settings.enabled.contains(&CheckCode::D208)
+            {
+                docstring_plugins::indent(self, &docstring);
+            }
             if self.settings.enabled.contains(&CheckCode::D209) {
                 docstring_plugins::newline_after_last_paragraph(self, &docstring);
             }

src/checks.rs

@@ -170,6 +170,9 @@ pub enum CheckCode {
     D203,
     D204,
     D205,
+    D206,
+    D207,
+    D208,
     D209,
     D210,
     D211,
@@ -309,6 +312,7 @@ pub enum CheckKind {
     EndsInPunctuation,
     FirstLineCapitalized,
     FitsOnOneLine,
+    IndentWithSpaces,
     MagicMethod,
     MultiLineSummaryFirstLine,
     MultiLineSummarySecondLine,
@@ -319,9 +323,11 @@ pub enum CheckKind {
     NoBlankLineBeforeClass(usize),
     NoBlankLineBeforeFunction(usize),
     NoBlankLinesBetweenHeaderAndContent(String),
+    NoOverIndentation,
     NoSignature,
     NoSurroundingWhitespace,
     NoThisPrefix,
+    NoUnderIndentation,
     NonEmpty,
     NonEmptySection(String),
     OneBlankLineAfterClass(usize),
@@ -473,6 +479,9 @@ impl CheckCode {
             CheckCode::D203 => CheckKind::OneBlankLineBeforeClass(0),
             CheckCode::D204 => CheckKind::OneBlankLineAfterClass(0),
             CheckCode::D205 => CheckKind::NoBlankLineAfterSummary,
+            CheckCode::D206 => CheckKind::IndentWithSpaces,
+            CheckCode::D207 => CheckKind::NoUnderIndentation,
+            CheckCode::D208 => CheckKind::NoOverIndentation,
             CheckCode::D209 => CheckKind::NewLineAfterLastParagraph,
             CheckCode::D210 => CheckKind::NoSurroundingWhitespace,
             CheckCode::D211 => CheckKind::NoBlankLineBeforeClass(1),
@@ -609,6 +618,7 @@ impl CheckKind {
             CheckKind::EndsInPunctuation => &CheckCode::D415,
             CheckKind::FirstLineCapitalized => &CheckCode::D403,
             CheckKind::FitsOnOneLine => &CheckCode::D200,
+            CheckKind::IndentWithSpaces => &CheckCode::D206,
             CheckKind::MagicMethod => &CheckCode::D105,
             CheckKind::MultiLineSummaryFirstLine => &CheckCode::D212,
             CheckKind::MultiLineSummarySecondLine => &CheckCode::D213,
@@ -619,9 +629,11 @@ impl CheckKind {
             CheckKind::NoBlankLineBeforeClass(_) => &CheckCode::D211,
             CheckKind::NoBlankLineBeforeFunction(_) => &CheckCode::D201,
             CheckKind::NoBlankLinesBetweenHeaderAndContent(_) => &CheckCode::D412,
+            CheckKind::NoOverIndentation => &CheckCode::D208,
             CheckKind::NoSignature => &CheckCode::D402,
             CheckKind::NoSurroundingWhitespace => &CheckCode::D210,
             CheckKind::NoThisPrefix => &CheckCode::D404,
+            CheckKind::NoUnderIndentation => &CheckCode::D207,
             CheckKind::NonEmpty => &CheckCode::D419,
             CheckKind::NonEmptySection(_) => &CheckCode::D414,
             CheckKind::OneBlankLineAfterClass(_) => &CheckCode::D204,
@@ -1009,6 +1021,11 @@ impl CheckKind {
                     format!("Missing argument descriptions in the docstring: {names}")
                 }
             }
+            CheckKind::IndentWithSpaces => {
+                "Docstring should be indented with spaces, not tabs".to_string()
+            }
+            CheckKind::NoUnderIndentation => "Docstring is under-indented".to_string(),
+            CheckKind::NoOverIndentation => "Docstring is over-indented".to_string(),
             // Meta
             CheckKind::UnusedNOQA(codes) => match codes {
                 None => "Unused `noqa` directive".to_string(),

src/docstrings/docstring_plugins.rs

@@ -9,6 +9,7 @@ use crate::check_ast::Checker;
 use crate::checks::{Check, CheckCode, CheckKind};
 use crate::docstrings::google::check_google_section;
 use crate::docstrings::helpers;
+use crate::docstrings::helpers::{indentation, leading_space};
 use crate::docstrings::numpy::check_numpy_section;
 use crate::docstrings::sections::section_contexts;
 use crate::docstrings::styles::SectionStyle;
@@ -303,6 +304,89 @@ pub fn blank_after_summary(checker: &mut Checker, definition: &Definition) {
     }
 }
 
+/// D206, D207, D208
+pub fn indent(checker: &mut Checker, definition: &Definition) {
+    if let Some(docstring) = definition.docstring {
+        if let ExprKind::Constant {
+            value: Constant::Str(string),
+            ..
+        } = &docstring.node
+        {
+            let lines: Vec<&str> = string.lines().collect();
+            if lines.len() <= 1 {
+                return;
+            }
+
+            let mut has_seen_tab = false;
+            let mut has_seen_over_indent = false;
+            let mut has_seen_under_indent = false;
+
+            let docstring_indent = indentation(checker, docstring).to_string();
+            if !has_seen_tab {
+                if docstring_indent.contains('\t') {
+                    if checker.settings.enabled.contains(&CheckCode::D206) {
+                        checker.add_check(Check::new(
+                            CheckKind::IndentWithSpaces,
+                            helpers::range_for(docstring),
+                        ));
+                    }
+                    has_seen_tab = true;
+                }
+            }
+
+            for i in 0..lines.len() {
+                // First lines and continuations doesn't need any indentation.
+                if i == 0 || lines[i - 1].ends_with('\\') {
+                    continue;
+                }
+
+                // Omit empty lines, except for the last line, which is non-empty by way of
+                // containing the closing quotation marks.
+                if i < lines.len() - 1 && lines[i].trim().is_empty() {
+                    continue;
+                }
+
+                let line_indent = leading_space(lines[i]);
+                if !has_seen_tab {
+                    if line_indent.contains('\t') {
+                        if checker.settings.enabled.contains(&CheckCode::D206) {
+                            checker.add_check(Check::new(
+                                CheckKind::IndentWithSpaces,
+                                helpers::range_for(docstring),
+                            ));
+                        }
+                        has_seen_tab = true;
+                    }
+                }
+
+                if !has_seen_over_indent {
+                    if line_indent.len() > docstring_indent.len() {
+                        if checker.settings.enabled.contains(&CheckCode::D208) {
+                            checker.add_check(Check::new(
+                                CheckKind::NoOverIndentation,
+                                helpers::range_for(docstring),
+                            ));
+                        }
+                        has_seen_over_indent = true;
+                    }
+                }
+
+                if !has_seen_under_indent {
+                    if line_indent.len() < docstring_indent.len() {
+                        if checker.settings.enabled.contains(&CheckCode::D207) {
+                            checker.add_check(Check::new(
+                                CheckKind::NoUnderIndentation,
+                                helpers::range_for(docstring),
+                            ));
+                        }
+                        has_seen_under_indent = true;
+                    }
+                }
+            }
+        }
+    }
+}
+
 /// D209
 pub fn newline_after_last_paragraph(checker: &mut Checker, definition: &Definition) {
     if let Some(docstring) = definition.docstring {

src/linter.rs

@@ -273,6 +273,9 @@ mod tests {
     #[test_case(CheckCode::D203, Path::new("D.py"); "D203")]
     #[test_case(CheckCode::D204, Path::new("D.py"); "D204")]
     #[test_case(CheckCode::D205, Path::new("D.py"); "D205")]
+    #[test_case(CheckCode::D206, Path::new("D.py"); "D206")]
+    #[test_case(CheckCode::D207, Path::new("D.py"); "D207")]
+    #[test_case(CheckCode::D208, Path::new("D.py"); "D208")]
     #[test_case(CheckCode::D209, Path::new("D.py"); "D209")]
     #[test_case(CheckCode::D210, Path::new("D.py"); "D210")]
     #[test_case(CheckCode::D211, Path::new("D.py"); "D211")]

src/snapshots/ruff__linter__tests__D206_D.py.snap

@@ -0,0 +1,6 @@
+---
+source: src/linter.rs
+expression: checks
+---
+[]
+

src/snapshots/ruff__linter__tests__D207_D.py.snap

@@ -0,0 +1,29 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: NoUnderIndentation
+  location:
+    row: 225
+    column: 5
+  end_location:
+    row: 229
+    column: 8
+  fix: ~
+- kind: NoUnderIndentation
+  location:
+    row: 235
+    column: 5
+  end_location:
+    row: 239
+    column: 4
+  fix: ~
+- kind: NoUnderIndentation
+  location:
+    row: 433
+    column: 37
+  end_location:
+    row: 436
+    column: 8
+  fix: ~
+

src/snapshots/ruff__linter__tests__D208_D.py.snap

@@ -0,0 +1,29 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: NoOverIndentation
+  location:
+    row: 245
+    column: 5
+  end_location:
+    row: 249
+    column: 8
+  fix: ~
+- kind: NoOverIndentation
+  location:
+    row: 255
+    column: 5
+  end_location:
+    row: 259
+    column: 12
+  fix: ~
+- kind: NoOverIndentation
+  location:
+    row: 265
+    column: 5
+  end_location:
+    row: 269
+    column: 8
+  fix: ~
+