server: add quick fixes to ignore rule violations (#613)

Author: sbdchd

Cargo.lock

@@ -42,10 +42,10 @@ fn comment_body(token: &SyntaxToken) -> Option<(&str, TextRange)> {
 }
 
 // TODO: maybe in a future version we can rename this to squawk-ignore-line
-const IGNORE_LINE_TEXT: &str = "squawk-ignore";
-const IGNORE_FILE_TEXT: &str = "squawk-ignore-file";
+pub const IGNORE_LINE_TEXT: &str = "squawk-ignore";
+pub const IGNORE_FILE_TEXT: &str = "squawk-ignore-file";
 
-fn ignore_rule_names(token: &SyntaxToken) -> Option<(&str, TextRange, IgnoreKind)> {
+pub fn ignore_rule_info(token: &SyntaxToken) -> Option<(&str, TextRange, IgnoreKind)> {
     if let Some((comment_body, range)) = comment_body(token) {
         let without_start = comment_body.trim_start();
         let trim_start_size = comment_body.len() - without_start.len();
@@ -74,7 +74,7 @@ pub(crate) fn find_ignores(ctx: &mut Linter, file: &SyntaxNode) {
             rowan::WalkEvent::Enter(NodeOrToken::Token(token))
                 if token.kind() == SyntaxKind::COMMENT =>
             {
-                if let Some((rule_names, range, kind)) = ignore_rule_names(&token) {
+                if let Some((rule_names, range, kind)) = ignore_rule_info(&token) {
                     let mut set = HashSet::new();
                     let mut offset = 0usize;
 

crates/squawk_linter/src/ignore.rs

@@ -15,7 +15,7 @@ use squawk_syntax::{Parse, SourceFile};
 
 pub use version::Version;
 
-mod ignore;
+pub mod ignore;
 mod ignore_index;
 mod version;
 mod visitors;
@@ -250,7 +250,7 @@ pub struct Edit {
     pub text: Option<String>,
 }
 impl Edit {
-    fn insert<T: Into<String>>(text: T, at: TextSize) -> Self {
+    pub fn insert<T: Into<String>>(text: T, at: TextSize) -> Self {
         Self {
             text_range: TextRange::new(at, at),
             text: Some(text.into()),

crates/squawk_linter/src/lib.rs

@@ -19,6 +19,7 @@ squawk_lexer.workspace = true
 squawk_linter.workspace = true
 squawk_syntax.workspace = true
 line-index.workspace = true
+insta.workspace = true
 
 [lints]
 workspace = true

crates/squawk_server/Cargo.toml

@@ -0,0 +1,19 @@
+use serde::{Deserialize, Serialize};
+
+pub(crate) const DIAGNOSTIC_NAME: &str = "squawk";
+
+// Based on Ruff's setup for LSP diagnostic edits
+// see: https://github.com/astral-sh/ruff/blob/1a368b0bf97c3d0246390679166bbd2d589acf39/crates/ruff_server/src/lint.rs#L31
+/// This is serialized on the diagnostic `data` field.
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub(crate) struct AssociatedDiagnosticData {
+    /// The message describing what the fix does, if it exists, or the diagnostic name otherwise.
+    pub(crate) title: String,
+    /// Edits to fix the diagnostic. If this is empty, a fix
+    /// does not exist.
+    pub(crate) edits: Vec<lsp_types::TextEdit>,
+    /// Edit to ignore the rule the line
+    pub(crate) ignore_line_edit: Option<lsp_types::TextEdit>,
+    /// Edit to ignore the rule for the file
+    pub(crate) ignore_file_edit: Option<lsp_types::TextEdit>,
+}

crates/squawk_server/src/diagnostic.rs

@@ -0,0 +1,190 @@
+use line_index::{LineIndex, TextSize};
+use squawk_linter::{
+    Edit, Rule, Violation,
+    ignore::{IGNORE_FILE_TEXT, IGNORE_LINE_TEXT},
+};
+use squawk_syntax::{Parse, SourceFile, SyntaxKind, SyntaxToken, ast::AstNode};
+
+const UNSUPPORTED_RULES: &[Rule] = &[Rule::UnusedIgnore];
+
+pub(crate) fn ignore_line_edit(
+    violation: &Violation,
+    line_index: &LineIndex,
+    parse: &Parse<SourceFile>,
+) -> Option<Edit> {
+    if UNSUPPORTED_RULES.contains(&violation.code) {
+        return None;
+    }
+    let tree = parse.tree();
+    let rule_name = violation.code.to_string();
+
+    let violation_line = line_index.line_col(violation.text_range.start());
+    let previous_line = violation_line.line.checked_sub(1)?;
+    let previous_line_offset = line_index.line(previous_line)?.start();
+    let previous_line_token = tree
+        .syntax()
+        .token_at_offset(previous_line_offset)
+        .right_biased()?;
+
+    match previous_line_token.kind() {
+        SyntaxKind::COMMENT if is_ignore_comment(&previous_line_token) => {
+            let (_str, range, _ignore_kind) =
+                squawk_linter::ignore::ignore_rule_info(&previous_line_token)?;
+            Some(Edit::insert(format!(" {rule_name},"), range.start()))
+        }
+        _ => Some(Edit::insert(
+            format!("-- {IGNORE_LINE_TEXT} {rule_name}\n"),
+            violation.text_range.start(),
+        )),
+    }
+}
+
+pub(crate) fn ignore_file_edit(
+    violation: &Violation,
+    _line_index: &LineIndex,
+    _parse: &Parse<SourceFile>,
+) -> Option<Edit> {
+    if UNSUPPORTED_RULES.contains(&violation.code) {
+        return None;
+    }
+    let rule_name = violation.code.to_string();
+    Some(Edit::insert(
+        format!("-- {IGNORE_FILE_TEXT} {rule_name}\n"),
+        TextSize::new(0),
+    ))
+}
+
+fn is_ignore_comment(token: &SyntaxToken) -> bool {
+    assert_eq!(token.kind(), SyntaxKind::COMMENT);
+    squawk_linter::ignore::ignore_rule_info(&token).is_some()
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{diagnostic::AssociatedDiagnosticData, lint::lint};
+
+    #[test]
+    fn ignore_line() {
+        let sql = "
+create table a (
+  a int
+);
+
+-- an existing comment that shouldn't get in the way of us adding a new ignore
+create table b (
+  b int
+);
+
+-- squawk-ignore prefer-text-field
+create table c (
+  b int
+);
+";
+        let ignore_line_edits = lint(sql)
+            .into_iter()
+            .flat_map(|x| {
+                let data = x.data?;
+                let associated_data: AssociatedDiagnosticData =
+                    serde_json::from_value(data).unwrap();
+                associated_data.ignore_line_edit
+            })
+            .collect::<Vec<_>>();
+        insta::assert_snapshot!(apply_text_edits(sql, ignore_line_edits), @r"
+    -- squawk-ignore prefer-robust-stmts
+    create table a (
+      a int
+    );
+
+    -- an existing comment that shouldn't get in the way of us adding a new ignore
+    -- squawk-ignore prefer-robust-stmts
+    create table b (
+      b int
+    );
+
+    -- squawk-ignore prefer-robust-stmts, prefer-text-field
+    create table c (
+      b int
+    );
+    ");
+    }
+
+    #[test]
+    fn ignore_file() {
+        let sql = "
+-- some existing comment
+create table a (
+  a int
+);
+
+create table b (
+  b int
+);
+
+create table c (
+  b int
+);
+";
+        let ignore_line_edits = lint(sql)
+            .into_iter()
+            .flat_map(|x| {
+                let data = x.data?;
+                let associated_data: AssociatedDiagnosticData =
+                    serde_json::from_value(data).unwrap();
+                associated_data.ignore_file_edit
+            })
+            .collect::<Vec<_>>();
+        insta::assert_snapshot!(apply_text_edits(sql, ignore_line_edits), @r"
+        -- squawk-ignore-file prefer-robust-stmts
+        -- squawk-ignore-file prefer-robust-stmts
+        -- squawk-ignore-file prefer-robust-stmts
+
+        -- some existing comment
+        create table a (
+          a int
+        );
+
+        create table b (
+          b int
+        );
+
+        create table c (
+          b int
+        );
+        ");
+    }
+
+    fn apply_text_edits(sql: &str, mut edits: Vec<lsp_types::TextEdit>) -> String {
+        use line_index::{LineCol, LineIndex};
+
+        // Sort edits by position (reverse order to apply from end to start)
+        edits.sort_by(|a, b| {
+            b.range
+                .start
+                .line
+                .cmp(&a.range.start.line)
+                .then_with(|| b.range.start.character.cmp(&a.range.start.character))
+        });
+
+        let line_index = LineIndex::new(sql);
+        let mut result = sql.to_string();
+
+        for edit in edits {
+            // Convert LSP positions to byte offsets
+            let start_offset = line_index.offset(LineCol {
+                line: edit.range.start.line,
+                col: edit.range.start.character,
+            });
+            let end_offset = line_index.offset(LineCol {
+                line: edit.range.end.line,
+                col: edit.range.end.character,
+            });
+
+            let start_byte: usize = start_offset.unwrap_or_default().into();
+            let end_byte: usize = end_offset.unwrap_or_default().into();
+
+            result.replace_range(start_byte..end_byte, &edit.new_text);
+        }
+
+        result
+    }
+}