ruff/crates/ty_python_semantic/src/suppression.rs

1435 lines
45 KiB
Rust

use smallvec::{SmallVec, smallvec};
use std::error::Error;
use std::fmt;
use std::fmt::Formatter;
use std::fmt::Write as _;
use thiserror::Error;
use crate::diagnostic::DiagnosticGuard;
use crate::lint::{GetLintError, Level, LintMetadata, LintRegistry, LintStatus};
use crate::types::TypeCheckDiagnostics;
use crate::{Db, declare_lint, lint::LintId};
use ruff_db::diagnostic::{
Annotation, Diagnostic, DiagnosticId, IntoDiagnosticMessage, Severity, Span,
};
use ruff_db::{files::File, parsed::parsed_module, source::source_text};
use ruff_diagnostics::{Edit, Fix};
use ruff_python_parser::TokenKind;
use ruff_python_trivia::Cursor;
use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
declare_lint! {
/// ## What it does
/// Checks for `type: ignore` or `ty: ignore` directives that are no longer applicable.
///
/// ## Why is this bad?
/// A `type: ignore` directive that no longer matches any diagnostic violations is likely
/// included by mistake, and should be removed to avoid confusion.
///
/// ## Examples
/// ```py
/// a = 20 / 2 # ty: ignore[division-by-zero]
/// ```
///
/// Use instead:
///
/// ```py
/// a = 20 / 2
/// ```
pub(crate) static UNUSED_IGNORE_COMMENT = {
summary: "detects unused `type: ignore` comments",
status: LintStatus::stable("0.0.1-alpha.1"),
default_level: Level::Ignore,
}
}
declare_lint! {
/// ## What it does
/// Checks for `ty: ignore[code]` where `code` isn't a known lint rule.
///
/// ## Why is this bad?
/// A `ty: ignore[code]` directive with a `code` that doesn't match
/// any known rule will not suppress any type errors, and is probably a mistake.
///
/// ## Examples
/// ```py
/// a = 20 / 0 # ty: ignore[division-by-zer]
/// ```
///
/// Use instead:
///
/// ```py
/// a = 20 / 0 # ty: ignore[division-by-zero]
/// ```
pub(crate) static IGNORE_COMMENT_UNKNOWN_RULE = {
summary: "detects `ty: ignore` comments that reference unknown rules",
status: LintStatus::stable("0.0.1-alpha.1"),
default_level: Level::Warn,
}
}
declare_lint! {
/// ## What it does
/// Checks for `type: ignore` and `ty: ignore` comments that are syntactically incorrect.
///
/// ## Why is this bad?
/// A syntactically incorrect ignore comment is probably a mistake and is useless.
///
/// ## Examples
/// ```py
/// a = 20 / 0 # type: ignoree
/// ```
///
/// Use instead:
///
/// ```py
/// a = 20 / 0 # type: ignore
/// ```
pub(crate) static INVALID_IGNORE_COMMENT = {
summary: "detects ignore comments that use invalid syntax",
status: LintStatus::stable("0.0.1-alpha.1"),
default_level: Level::Warn,
}
}
#[salsa::tracked(returns(ref), heap_size=ruff_memory_usage::heap_size)]
pub(crate) fn suppressions(db: &dyn Db, file: File) -> Suppressions {
let parsed = parsed_module(db, file).load(db);
let source = source_text(db, file);
let mut builder = SuppressionsBuilder::new(&source, db.lint_registry());
let mut line_start = TextSize::default();
for token in parsed.tokens() {
if !token.kind().is_trivia() {
builder.set_seen_non_trivia_token();
}
match token.kind() {
TokenKind::Comment => {
let parser = SuppressionParser::new(&source, token.range());
for comment in parser {
match comment {
Ok(comment) => {
builder.add_comment(comment, TextRange::new(line_start, token.end()));
}
Err(error) => match error.kind {
ParseErrorKind::NotASuppression
| ParseErrorKind::CommentWithoutHash => {
// Skip non suppression comments and comments that miss a hash (shouldn't ever happen)
}
ParseErrorKind::NoWhitespaceAfterIgnore(kind)
| ParseErrorKind::CodesMissingComma(kind)
| ParseErrorKind::InvalidCode(kind)
| ParseErrorKind::CodesMissingClosingBracket(kind) => {
builder.add_invalid_comment(kind, error);
}
},
}
}
}
TokenKind::Newline | TokenKind::NonLogicalNewline => {
line_start = token.end();
}
_ => {}
}
}
builder.finish()
}
pub(crate) fn check_suppressions(
db: &dyn Db,
file: File,
diagnostics: TypeCheckDiagnostics,
) -> Vec<Diagnostic> {
let mut context = CheckSuppressionsContext::new(db, file, diagnostics);
check_unknown_rule(&mut context);
check_invalid_suppression(&mut context);
check_unused_suppressions(&mut context);
context.diagnostics.into_inner().into_diagnostics()
}
/// Checks for `ty: ignore` comments that reference unknown rules.
fn check_unknown_rule(context: &mut CheckSuppressionsContext) {
if context.is_lint_disabled(&IGNORE_COMMENT_UNKNOWN_RULE) {
return;
}
for unknown in &context.suppressions.unknown {
if let Some(diag) = context.report_lint(&IGNORE_COMMENT_UNKNOWN_RULE, unknown.range) {
diag.into_diagnostic(&unknown.reason);
}
}
}
fn check_invalid_suppression(context: &mut CheckSuppressionsContext) {
if context.is_lint_disabled(&INVALID_IGNORE_COMMENT) {
return;
}
for invalid in &context.suppressions.invalid {
if let Some(diag) = context.report_lint(&INVALID_IGNORE_COMMENT, invalid.error.range) {
diag.into_diagnostic(format_args!(
"Invalid `{kind}` comment: {reason}",
kind = invalid.kind,
reason = &invalid.error
));
}
}
}
/// Checks for unused suppression comments in `file` and
/// adds diagnostic for each of them to `diagnostics`.
///
/// Does nothing if the [`UNUSED_IGNORE_COMMENT`] rule is disabled.
fn check_unused_suppressions(context: &mut CheckSuppressionsContext) {
if context.is_lint_disabled(&UNUSED_IGNORE_COMMENT) {
return;
}
let diagnostics = context.diagnostics.get_mut();
let all = context.suppressions;
let mut unused = Vec::with_capacity(
all.file
.len()
.saturating_add(all.line.len())
.saturating_sub(diagnostics.used_len()),
);
// Collect all suppressions that are unused after type-checking.
for suppression in all {
if diagnostics.is_used(suppression.id()) {
continue;
}
// `unused-ignore-comment` diagnostics can only be suppressed by specifying a
// code. This is necessary because every `type: ignore` would implicitly also
// suppress its own unused-ignore-comment diagnostic.
if let Some(unused_suppression) = all
.lint_suppressions(suppression.range, LintId::of(&UNUSED_IGNORE_COMMENT))
.find(|unused_ignore_suppression| unused_ignore_suppression.target.is_lint())
{
// A `unused-ignore-comment` suppression can't ignore itself.
// It can only ignore other suppressions.
if unused_suppression.id() != suppression.id() {
diagnostics.mark_used(unused_suppression.id());
continue;
}
}
unused.push(suppression);
}
let mut unused_iter = unused
.iter()
.filter(|suppression| {
// This looks silly but it's necessary to check again if a `unused-ignore-comment` is indeed unused
// in case the "unused" directive comes after it:
// ```py
// a = 10 / 2 # ty: ignore[unused-ignore-comment, division-by-zero]
// ```
!context.is_suppression_used(suppression.id())
})
.peekable();
let source = source_text(context.db, context.file);
while let Some(suppression) = unused_iter.next() {
let mut diag = match suppression.target {
SuppressionTarget::All => {
let Some(diag) =
context.report_unchecked(&UNUSED_IGNORE_COMMENT, suppression.range)
else {
continue;
};
diag.into_diagnostic(format_args!(
"Unused blanket `{}` directive",
suppression.kind
))
}
SuppressionTarget::Lint(lint) => {
// A single code in a `ty: ignore[<code1>, <code2>, ...]` directive
// Is this the first code directly after the `[`?
let includes_first_code = source[..suppression.range.start().to_usize()]
.trim_end()
.ends_with('[');
let mut current = suppression;
let mut unused_codes = Vec::new();
// Group successive codes together into a single diagnostic,
// or report the entire directive if all codes are unused.
while let Some(next) = unused_iter.peek() {
if let SuppressionTarget::Lint(next_lint) = next.target
&& next.comment_range == current.comment_range
&& source[TextRange::new(current.range.end(), next.range.start())]
.chars()
.all(|c| c.is_whitespace() || c == ',')
{
unused_codes.push(next_lint);
current = *next;
unused_iter.next();
} else {
break;
}
}
// Is the last suppression code the last code before the closing `]`.
let includes_last_code = source[current.range.end().to_usize()..]
.trim_start()
.starts_with(']');
// If only some codes are unused
if !includes_first_code || !includes_last_code {
let mut codes = format!("'{}'", lint.name());
for code in &unused_codes {
let _ = write!(&mut codes, ", '{code}'", code = code.name());
}
if let Some(diag) = context.report_unchecked(
&UNUSED_IGNORE_COMMENT,
TextRange::new(suppression.range.start(), current.range.end()),
) {
let mut diag = diag.into_diagnostic(format_args!(
"Unused `{kind}` directive: {codes}",
kind = suppression.kind
));
diag.primary_annotation_mut()
.unwrap()
.push_tag(ruff_db::diagnostic::DiagnosticTag::Unnecessary);
// Delete everything up to the start of the next code.
let trailing_len: TextSize = source[current.range.end().to_usize()..]
.chars()
.take_while(|c: &char| c.is_whitespace() || *c == ',')
.map(TextLen::text_len)
.sum();
// If we delete the last codes before `]`, ensure we delete any trailing comma
let leading_len: TextSize = if includes_last_code {
source[..suppression.range.start().to_usize()]
.chars()
.rev()
.take_while(|c: &char| c.is_whitespace() || *c == ',')
.map(TextLen::text_len)
.sum()
} else {
TextSize::default()
};
let fix_range = TextRange::new(
suppression.range.start() - leading_len,
current.range.end() + trailing_len,
);
diag.set_fix(Fix::safe_edit(Edit::range_deletion(fix_range)));
if unused_codes.is_empty() {
diag.help("Remove the unused suppression code");
} else {
diag.help("Remove the unused suppression codes");
}
}
continue;
}
// All codes are unused
let Some(diag) =
context.report_unchecked(&UNUSED_IGNORE_COMMENT, suppression.comment_range)
else {
continue;
};
diag.into_diagnostic(format_args!(
"Unused `{kind}` directive",
kind = suppression.kind
))
}
SuppressionTarget::Empty => {
let Some(diag) =
context.report_unchecked(&UNUSED_IGNORE_COMMENT, suppression.range)
else {
continue;
};
diag.into_diagnostic(format_args!(
"Unused `{kind}` without a code",
kind = suppression.kind
))
}
};
diag.primary_annotation_mut()
.unwrap()
.push_tag(ruff_db::diagnostic::DiagnosticTag::Unnecessary);
diag.set_fix(remove_comment_fix(suppression, &source));
diag.help("Remove the unused suppression comment");
}
}
/// Creates a fix for adding a suppression comment to suppress `lint` for `range`.
///
/// The fix prefers adding the code to an existing `ty: ignore[]` comment over
/// adding a new suppression comment.
pub fn create_suppression_fix(db: &dyn Db, file: File, id: LintId, range: TextRange) -> Fix {
let suppressions = suppressions(db, file);
let source = source_text(db, file);
let mut existing_suppressions = suppressions.line_suppressions(range).filter(|suppression| {
matches!(
suppression.target,
SuppressionTarget::Lint(_) | SuppressionTarget::Empty,
)
});
// If there's an existing `ty: ignore[]` comment, append the code to it instead of creating a new suppression comment.
if let Some(existing) = existing_suppressions.next() {
let comment_text = &source[existing.comment_range];
// Only add to the existing ignore comment if it has no reason.
if let Some(before_closing_paren) = comment_text.trim_end().strip_suffix(']') {
let up_to_last_code = before_closing_paren.trim_end();
let insertion = if up_to_last_code.ends_with(',') {
format!(" {id}", id = id.name())
} else {
format!(", {id}", id = id.name())
};
let relative_offset_from_end = comment_text.text_len() - up_to_last_code.text_len();
return Fix::safe_edit(Edit::insertion(
insertion,
existing.comment_range.end() - relative_offset_from_end,
));
}
}
// Always insert a new suppression at the end of the range to avoid having to deal with multiline strings
// etc.
let parsed = parsed_module(db, file).load(db);
let tokens_after = parsed.tokens().after(range.end());
// Same as for `line_end` when building up the `suppressions`: Ignore newlines
// in multiline-strings, inside f-strings, or after a line continuation because we can't
// place a comment on those lines.
let line_end = tokens_after
.iter()
.find(|token| {
matches!(
token.kind(),
TokenKind::Newline | TokenKind::NonLogicalNewline
)
})
.map(Ranged::start)
.unwrap_or(source.text_len());
let up_to_line_end = &source[..line_end.to_usize()];
let up_to_first_content = up_to_line_end.trim_end();
let trailing_whitespace_len = up_to_line_end.text_len() - up_to_first_content.text_len();
let insertion = format!(" # ty:ignore[{id}]", id = id.name());
Fix::safe_edit(if trailing_whitespace_len == TextSize::ZERO {
Edit::insertion(insertion, line_end)
} else {
// `expr # fmt: off<trailing_whitespace>`
// Trim the trailing whitespace
Edit::replacement(insertion, line_end - trailing_whitespace_len, line_end)
})
}
struct CheckSuppressionsContext<'a> {
db: &'a dyn Db,
file: File,
suppressions: &'a Suppressions,
diagnostics: std::cell::RefCell<TypeCheckDiagnostics>,
}
impl<'a> CheckSuppressionsContext<'a> {
fn new(db: &'a dyn Db, file: File, diagnostics: TypeCheckDiagnostics) -> Self {
let suppressions = suppressions(db, file);
Self {
db,
file,
suppressions,
diagnostics: diagnostics.into(),
}
}
fn is_lint_disabled(&self, lint: &'static LintMetadata) -> bool {
!self
.db
.rule_selection(self.file)
.is_enabled(LintId::of(lint))
}
fn is_suppression_used(&self, id: FileSuppressionId) -> bool {
self.diagnostics.borrow().is_used(id)
}
fn report_lint<'ctx>(
&'ctx self,
lint: &'static LintMetadata,
range: TextRange,
) -> Option<SuppressionDiagnosticGuardBuilder<'ctx, 'a>> {
if let Some(suppression) = self.suppressions.find_suppression(range, LintId::of(lint)) {
self.diagnostics.borrow_mut().mark_used(suppression.id());
return None;
}
self.report_unchecked(lint, range)
}
/// Reports a diagnostic without checking if the lint at the given range is suppressed or marking
/// the suppression as used.
fn report_unchecked<'ctx>(
&'ctx self,
lint: &'static LintMetadata,
range: TextRange,
) -> Option<SuppressionDiagnosticGuardBuilder<'ctx, 'a>> {
SuppressionDiagnosticGuardBuilder::new(self, lint, range)
}
}
/// A builder for constructing a diagnostic guard.
///
/// This type exists to separate the phases of "check if a diagnostic should
/// be reported" and "build the actual diagnostic."
pub(crate) struct SuppressionDiagnosticGuardBuilder<'ctx, 'db> {
ctx: &'ctx CheckSuppressionsContext<'db>,
id: DiagnosticId,
range: TextRange,
severity: Severity,
}
impl<'ctx, 'db> SuppressionDiagnosticGuardBuilder<'ctx, 'db> {
fn new(
ctx: &'ctx CheckSuppressionsContext<'db>,
lint: &'static LintMetadata,
range: TextRange,
) -> Option<Self> {
let severity = ctx.db.rule_selection(ctx.file).severity(LintId::of(lint))?;
Some(Self {
ctx,
id: DiagnosticId::Lint(lint.name()),
severity,
range,
})
}
/// Create a new guard.
///
/// This initializes a new diagnostic using the given message along with
/// the ID and severity used to create this builder.
///
/// The diagnostic can be further mutated on the guard via its `DerefMut`
/// impl to `Diagnostic`.
pub(crate) fn into_diagnostic(
self,
message: impl IntoDiagnosticMessage,
) -> DiagnosticGuard<'ctx> {
let mut diag = Diagnostic::new(self.id, self.severity, message);
let primary_span = Span::from(self.ctx.file).with_range(self.range);
diag.annotate(Annotation::primary(primary_span));
DiagnosticGuard::new(self.ctx.file, &self.ctx.diagnostics, diag)
}
}
/// The suppressions of a single file.
#[derive(Debug, Eq, PartialEq, get_size2::GetSize)]
pub(crate) struct Suppressions {
/// Suppressions that apply to the entire file.
///
/// The suppressions are sorted by [`Suppression::comment_range`] and the [`Suppression::suppressed_range`]
/// spans the entire file.
///
/// For now, this is limited to `type: ignore` comments.
file: SmallVec<[Suppression; 1]>,
/// Suppressions that apply to a specific line (or lines).
///
/// Comments with multiple codes create multiple [`Suppression`]s that all share the same [`Suppression::comment_range`].
///
/// The suppressions are sorted by [`Suppression::range`] (which implies [`Suppression::comment_range`]).
line: Vec<Suppression>,
/// Suppressions with lint codes that are unknown.
unknown: Vec<UnknownSuppression>,
/// Suppressions that are syntactically invalid.
invalid: Vec<InvalidSuppression>,
}
impl Suppressions {
pub(crate) fn find_suppression(&self, range: TextRange, id: LintId) -> Option<&Suppression> {
self.lint_suppressions(range, id).next()
}
/// Returns all suppressions for the given lint
fn lint_suppressions(
&self,
range: TextRange,
id: LintId,
) -> impl Iterator<Item = &Suppression> + '_ {
self.file
.iter()
.chain(self.line_suppressions(range))
.filter(move |suppression| suppression.matches(id))
}
/// Returns the line-level suppressions that apply for `range`.
///
/// A suppression applies for the given range if it contains the range's
/// start or end offset. This means the suppression is on the same line
/// as the diagnostic's start or end.
fn line_suppressions(&self, range: TextRange) -> impl Iterator<Item = &Suppression> + '_ {
// First find the index of the suppression comment that ends right before the range
// starts. This allows us to skip suppressions that are not relevant for the range.
let end_offset = self
.line
.binary_search_by_key(&range.start(), |suppression| {
suppression.suppressed_range.end()
})
.unwrap_or_else(|index| index);
// From here, search the remaining suppression comments for one that
// contains the range's start or end offset. Stop the search
// as soon as the suppression's range and the range no longer overlap.
self.line[end_offset..]
.iter()
// Stop searching if the suppression starts after the range we're looking for.
.take_while(move |suppression| range.end() >= suppression.suppressed_range.start())
.filter(move |suppression| {
// Don't use intersect to avoid that suppressions on inner-expression
// ignore errors for outer expressions
suppression.suppressed_range.contains(range.start())
|| suppression.suppressed_range.contains(range.end())
})
}
fn iter(&self) -> SuppressionsIter<'_> {
self.file.iter().chain(&self.line)
}
}
pub(crate) type SuppressionsIter<'a> =
std::iter::Chain<std::slice::Iter<'a, Suppression>, std::slice::Iter<'a, Suppression>>;
impl<'a> IntoIterator for &'a Suppressions {
type Item = &'a Suppression;
type IntoIter = SuppressionsIter<'a>;
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
/// A `type: ignore` or `ty: ignore` suppression.
///
/// Suppression comments that suppress multiple codes
/// create multiple suppressions: one for every code.
/// They all share the same `comment_range`.
#[derive(Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
pub(crate) struct Suppression {
target: SuppressionTarget,
kind: SuppressionKind,
/// The range of the code in this suppression.
///
/// This is the same as the `comment_range` for the
/// targets [`SuppressionTarget::All`] and [`SuppressionTarget::Empty`].
range: TextRange,
/// The range of the suppression comment.
///
/// This isn't the range of the entire comment if this is a nested comment:
///
/// ```py
/// a # ty: ignore # fmt: off
/// ^^^^^^^^^^^^^
/// ```
///
/// It doesn't include the range of the nested `# fmt: off` comment.
comment_range: TextRange,
/// The range for which this suppression applies.
/// Most of the time, this is the range of the comment's line.
/// However, there are few cases where the range gets expanded to
/// cover multiple lines:
/// * multiline strings: `expr + """multiline\nstring""" # type: ignore`
/// * line continuations: `expr \ + "test" # type: ignore`
suppressed_range: TextRange,
}
impl Suppression {
fn matches(&self, tested_id: LintId) -> bool {
match self.target {
SuppressionTarget::All => true,
SuppressionTarget::Lint(suppressed_id) => tested_id == suppressed_id,
SuppressionTarget::Empty => false,
}
}
pub(crate) fn id(&self) -> FileSuppressionId {
FileSuppressionId(self.range)
}
}
/// Unique ID for a suppression in a file.
///
/// ## Implementation
/// The wrapped `TextRange` is the suppression's range.
/// This is unique enough because it is its exact
/// location in the source.
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, get_size2::GetSize)]
pub(crate) struct FileSuppressionId(TextRange);
#[derive(Copy, Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
enum SuppressionTarget {
/// Suppress all lints
All,
/// Suppress the lint with the given id
Lint(LintId),
/// Suppresses no lint, e.g. `ty: ignore[]`
Empty,
}
impl SuppressionTarget {
const fn is_lint(self) -> bool {
matches!(self, SuppressionTarget::Lint(_))
}
}
struct SuppressionsBuilder<'a> {
lint_registry: &'a LintRegistry,
source: &'a str,
/// `type: ignore` comments at the top of the file before any non-trivia code apply to the entire file.
/// This boolean tracks if there has been any non trivia token.
seen_non_trivia_token: bool,
line: Vec<Suppression>,
file: SmallVec<[Suppression; 1]>,
unknown: Vec<UnknownSuppression>,
invalid: Vec<InvalidSuppression>,
}
impl<'a> SuppressionsBuilder<'a> {
fn new(source: &'a str, lint_registry: &'a LintRegistry) -> Self {
Self {
source,
lint_registry,
seen_non_trivia_token: false,
line: Vec::new(),
file: SmallVec::new_const(),
unknown: Vec::new(),
invalid: Vec::new(),
}
}
fn set_seen_non_trivia_token(&mut self) {
self.seen_non_trivia_token = true;
}
fn finish(mut self) -> Suppressions {
self.line.shrink_to_fit();
self.file.shrink_to_fit();
self.unknown.shrink_to_fit();
self.invalid.shrink_to_fit();
Suppressions {
file: self.file,
line: self.line,
unknown: self.unknown,
invalid: self.invalid,
}
}
fn add_comment(&mut self, comment: SuppressionComment, line_range: TextRange) {
// `type: ignore` comments at the start of the file apply to the entire range.
// > A # type: ignore comment on a line by itself at the top of a file, before any docstrings,
// > imports, or other executable code, silences all errors in the file.
// > Blank lines and other comments, such as shebang lines and coding cookies,
// > may precede the # type: ignore comment.
// > https://typing.python.org/en/latest/spec/directives.html#type-ignore-comments
let is_file_suppression = comment.kind.is_type_ignore() && !self.seen_non_trivia_token;
let suppressed_range = if is_file_suppression {
TextRange::new(0.into(), self.source.text_len())
} else {
line_range
};
let mut push_type_ignore_suppression = |suppression: Suppression| {
if is_file_suppression {
self.file.push(suppression);
} else {
self.line.push(suppression);
}
};
match comment.codes {
// `type: ignore`
None => {
push_type_ignore_suppression(Suppression {
target: SuppressionTarget::All,
kind: comment.kind,
comment_range: comment.range,
range: comment.range,
suppressed_range,
});
}
// `type: ignore[..]`
// The suppression applies to all lints if it is a `type: ignore`
// comment. `type: ignore` apply to all lints for better mypy compatibility.
Some(_) if comment.kind.is_type_ignore() => {
push_type_ignore_suppression(Suppression {
target: SuppressionTarget::All,
kind: comment.kind,
comment_range: comment.range,
range: comment.range,
suppressed_range,
});
}
// `ty: ignore[]`
Some(codes) if codes.is_empty() => {
self.line.push(Suppression {
target: SuppressionTarget::Empty,
kind: comment.kind,
range: comment.range,
comment_range: comment.range,
suppressed_range,
});
}
// `ty: ignore[a, b]`
Some(codes) => {
for code_range in codes {
let code = &self.source[code_range];
match self.lint_registry.get(code) {
Ok(lint) => {
self.line.push(Suppression {
target: SuppressionTarget::Lint(lint),
kind: comment.kind,
range: code_range,
comment_range: comment.range,
suppressed_range,
});
}
Err(error) => self.unknown.push(UnknownSuppression {
range: code_range,
comment_range: comment.range,
reason: error,
}),
}
}
}
}
}
fn add_invalid_comment(&mut self, kind: SuppressionKind, error: ParseError) {
self.invalid.push(InvalidSuppression { kind, error });
}
}
/// Suppression for an unknown lint rule.
#[derive(Debug, PartialEq, Eq, get_size2::GetSize)]
struct UnknownSuppression {
/// The range of the code.
range: TextRange,
/// The range of the suppression comment
comment_range: TextRange,
reason: GetLintError,
}
#[derive(Debug, PartialEq, Eq, get_size2::GetSize)]
struct InvalidSuppression {
kind: SuppressionKind,
error: ParseError,
}
struct SuppressionParser<'src> {
cursor: Cursor<'src>,
range: TextRange,
}
impl<'src> SuppressionParser<'src> {
fn new(source: &'src str, range: TextRange) -> Self {
let cursor = Cursor::new(&source[range]);
Self { cursor, range }
}
fn parse_comment(&mut self) -> Result<SuppressionComment, ParseError> {
let comment_start = self.offset();
self.cursor.start_token();
if !self.cursor.eat_char('#') {
return self.syntax_error(ParseErrorKind::CommentWithoutHash);
}
self.eat_whitespace();
// type: ignore[code]
// ^^^^^^^^^^^^
let Some(kind) = self.eat_kind() else {
return Err(ParseError::new(
ParseErrorKind::NotASuppression,
TextRange::new(comment_start, self.offset()),
));
};
let has_trailing_whitespace = self.eat_whitespace();
// type: ignore[code1, code2]
// ^^^^^^
let codes = self.eat_codes(kind)?;
if self.cursor.is_eof() || codes.is_some() || has_trailing_whitespace {
// Consume the comment until its end or until the next "sub-comment" starts.
self.cursor.eat_while(|c| c != '#');
Ok(SuppressionComment {
kind,
codes,
range: TextRange::at(comment_start, self.cursor.token_len()),
})
} else {
self.syntax_error(ParseErrorKind::NoWhitespaceAfterIgnore(kind))
}
}
fn eat_kind(&mut self) -> Option<SuppressionKind> {
let kind = if self.cursor.as_str().starts_with("type") {
SuppressionKind::TypeIgnore
} else if self.cursor.as_str().starts_with("ty") {
SuppressionKind::Ty
} else {
return None;
};
self.cursor.skip_bytes(kind.len_utf8());
self.eat_whitespace();
if !self.cursor.eat_char(':') {
return None;
}
self.eat_whitespace();
if !self.cursor.as_str().starts_with("ignore") {
return None;
}
self.cursor.skip_bytes("ignore".len());
Some(kind)
}
fn eat_codes(
&mut self,
kind: SuppressionKind,
) -> Result<Option<SmallVec<[TextRange; 2]>>, ParseError> {
if !self.cursor.eat_char('[') {
return Ok(None);
}
let mut codes: SmallVec<[TextRange; 2]> = smallvec![];
loop {
if self.cursor.is_eof() {
return self.syntax_error(ParseErrorKind::CodesMissingClosingBracket(kind));
}
self.eat_whitespace();
// `ty: ignore[]` or `ty: ignore[a,]`
if self.cursor.eat_char(']') {
break Ok(Some(codes));
}
let code_start = self.offset();
if !self.eat_word() {
return self.syntax_error(ParseErrorKind::InvalidCode(kind));
}
codes.push(TextRange::new(code_start, self.offset()));
self.eat_whitespace();
if !self.cursor.eat_char(',') {
if self.cursor.eat_char(']') {
break Ok(Some(codes));
}
// `ty: ignore[a b]
return self.syntax_error(ParseErrorKind::CodesMissingComma(kind));
}
}
}
fn eat_whitespace(&mut self) -> bool {
if self.cursor.eat_if(char::is_whitespace) {
self.cursor.eat_while(char::is_whitespace);
true
} else {
false
}
}
fn eat_word(&mut self) -> bool {
if self.cursor.eat_if(char::is_alphabetic) {
// Allow `:` for better error recovery when someone uses `lint:code` instead of just `code`.
self.cursor
.eat_while(|c| c.is_alphanumeric() || matches!(c, '_' | '-' | ':'));
true
} else {
false
}
}
fn syntax_error<T>(&self, kind: ParseErrorKind) -> Result<T, ParseError> {
let len = if self.cursor.is_eof() {
TextSize::default()
} else {
self.cursor.first().text_len()
};
Err(ParseError::new(kind, TextRange::at(self.offset(), len)))
}
fn offset(&self) -> TextSize {
self.range.start() + self.range.len() - self.cursor.text_len()
}
}
impl Iterator for SuppressionParser<'_> {
type Item = Result<SuppressionComment, ParseError>;
fn next(&mut self) -> Option<Self::Item> {
if self.cursor.is_eof() {
return None;
}
match self.parse_comment() {
Ok(result) => Some(Ok(result)),
Err(error) => {
self.cursor.eat_while(|c| c != '#');
Some(Err(error))
}
}
}
}
/// A single parsed suppression comment.
#[derive(Clone, Debug, Eq, PartialEq)]
struct SuppressionComment {
/// The range of the suppression comment.
///
/// This can be a sub-range of the comment token if the comment token contains multiple `#` tokens:
/// ```py
/// # fmt: off # type: ignore
/// ^^^^^^^^^^^^^^
/// ```
range: TextRange,
kind: SuppressionKind,
/// The ranges of the codes in the optional `[...]`.
/// `None` for comments that don't specify any code.
///
/// ```py
/// # type: ignore[unresolved-reference, invalid-exception-caught]
/// ^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^
/// ```
codes: Option<SmallVec<[TextRange; 2]>>,
}
#[derive(Copy, Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
enum SuppressionKind {
TypeIgnore,
Ty,
}
impl SuppressionKind {
const fn is_type_ignore(self) -> bool {
matches!(self, SuppressionKind::TypeIgnore)
}
fn len_utf8(self) -> usize {
match self {
SuppressionKind::TypeIgnore => "type".len(),
SuppressionKind::Ty => "ty".len(),
}
}
}
impl fmt::Display for SuppressionKind {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
SuppressionKind::TypeIgnore => f.write_str("type: ignore"),
SuppressionKind::Ty => f.write_str("ty: ignore"),
}
}
}
#[derive(Debug, Eq, PartialEq, Clone, get_size2::GetSize)]
struct ParseError {
kind: ParseErrorKind,
/// The position/range at which the parse error occurred.
range: TextRange,
}
impl ParseError {
fn new(kind: ParseErrorKind, range: TextRange) -> Self {
Self { kind, range }
}
}
impl fmt::Display for ParseError {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
self.kind.fmt(f)
}
}
impl Error for ParseError {}
#[derive(Debug, Eq, PartialEq, Clone, Error, get_size2::GetSize)]
enum ParseErrorKind {
/// The comment isn't a suppression comment.
#[error("not a suppression comment")]
NotASuppression,
#[error("the comment doesn't start with a `#`")]
CommentWithoutHash,
/// A valid suppression `type: ignore` but it misses a whitespaces after the `ignore` keyword.
///
/// ```py
/// type: ignoree
/// ```
#[error("no whitespace after `ignore`")]
NoWhitespaceAfterIgnore(SuppressionKind),
/// Missing comma between two codes
#[error("expected a comma separating the rule codes")]
CodesMissingComma(SuppressionKind),
/// `ty: ignore[*.*]`
#[error("expected a alphanumeric character or `-` or `_` as code")]
InvalidCode(SuppressionKind),
/// `ty: ignore[a, b`
#[error("expected a closing bracket")]
CodesMissingClosingBracket(SuppressionKind),
}
fn remove_comment_fix(suppression: &Suppression, source: &str) -> Fix {
let comment_end = suppression.comment_range.end();
let comment_start = suppression.comment_range.start();
let after_comment = &source[comment_end.to_usize()..];
if !after_comment.starts_with(['\n', '\r']) {
// For example: `# ty: ignore # fmt: off`
// Don't remove the trailing whitespace up to the `ty: ignore` comment
return Fix::safe_edit(Edit::range_deletion(suppression.comment_range));
}
// Remove any leading whitespace before the comment
// to avoid unnecessary trailing whitespace once the comment is removed
let before_comment = &source[..comment_start.to_usize()];
let mut leading_len = TextSize::default();
for c in before_comment.chars().rev() {
match c {
'\n' | '\r' => break,
c if c.is_whitespace() => leading_len += c.text_len(),
_ => break,
}
}
Fix::safe_edit(Edit::range_deletion(TextRange::new(
comment_start - leading_len,
comment_end,
)))
}
#[cfg(test)]
mod tests {
use crate::suppression::{SuppressionComment, SuppressionParser};
use insta::assert_debug_snapshot;
use ruff_text_size::{TextLen, TextRange};
use std::fmt;
use std::fmt::Formatter;
#[test]
fn type_ignore_no_codes() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore",
),
@r##"
[
SuppressionComment {
text: "# type: ignore",
kind: TypeIgnore,
codes: [],
},
]
"##
);
}
#[test]
fn type_ignore_explanation() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore I tried but couldn't figure out the proper type",
),
@r##"
[
SuppressionComment {
text: "# type: ignore I tried but couldn't figure out the proper type",
kind: TypeIgnore,
codes: [],
},
]
"##
);
}
#[test]
fn fmt_comment_before_type_ignore() {
assert_debug_snapshot!(
SuppressionComments::new(
"# fmt: off # type: ignore",
),
@r##"
[
SuppressionComment {
text: "# type: ignore",
kind: TypeIgnore,
codes: [],
},
]
"##
);
}
#[test]
fn type_ignore_before_fmt_off() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore # fmt: off",
),
@r##"
[
SuppressionComment {
text: "# type: ignore ",
kind: TypeIgnore,
codes: [],
},
]
"##
);
}
#[test]
fn multiple_type_ignore_comments() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore[a] # type: ignore[b]",
),
@r##"
[
SuppressionComment {
text: "# type: ignore[a] ",
kind: TypeIgnore,
codes: [
"a",
],
},
SuppressionComment {
text: "# type: ignore[b]",
kind: TypeIgnore,
codes: [
"b",
],
},
]
"##
);
}
#[test]
fn invalid_type_ignore_valid_type_ignore() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore[a # type: ignore[b]",
),
@r##"
[
SuppressionComment {
text: "# type: ignore[b]",
kind: TypeIgnore,
codes: [
"b",
],
},
]
"##
);
}
#[test]
fn valid_type_ignore_invalid_type_ignore() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore[a] # type: ignoreeee",
),
@r##"
[
SuppressionComment {
text: "# type: ignore[a] ",
kind: TypeIgnore,
codes: [
"a",
],
},
]
"##
);
}
#[test]
fn type_ignore_multiple_codes() {
assert_debug_snapshot!(
SuppressionComments::new(
"# type: ignore[invalid-exception-raised, invalid-exception-caught]",
),
@r##"
[
SuppressionComment {
text: "# type: ignore[invalid-exception-raised, invalid-exception-caught]",
kind: TypeIgnore,
codes: [
"invalid-exception-raised",
"invalid-exception-caught",
],
},
]
"##
);
}
#[test]
fn type_ignore_single_code() {
assert_debug_snapshot!(
SuppressionComments::new("# type: ignore[invalid-exception-raised]",),
@r##"
[
SuppressionComment {
text: "# type: ignore[invalid-exception-raised]",
kind: TypeIgnore,
codes: [
"invalid-exception-raised",
],
},
]
"##
);
}
struct SuppressionComments<'a> {
source: &'a str,
}
impl<'a> SuppressionComments<'a> {
fn new(source: &'a str) -> Self {
Self { source }
}
}
impl fmt::Debug for SuppressionComments<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut list = f.debug_list();
for comment in SuppressionParser::new(
self.source,
TextRange::new(0.into(), self.source.text_len()),
)
.flatten()
{
list.entry(&comment.debug(self.source));
}
list.finish()
}
}
impl SuppressionComment {
fn debug<'a>(&'a self, source: &'a str) -> DebugSuppressionComment<'a> {
DebugSuppressionComment {
source,
comment: self,
}
}
}
struct DebugSuppressionComment<'a> {
source: &'a str,
comment: &'a SuppressionComment,
}
impl fmt::Debug for DebugSuppressionComment<'_> {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
struct DebugCodes<'a> {
source: &'a str,
codes: &'a [TextRange],
}
impl fmt::Debug for DebugCodes<'_> {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
let mut f = f.debug_list();
for code in self.codes {
f.entry(&&self.source[*code]);
}
f.finish()
}
}
f.debug_struct("SuppressionComment")
.field("text", &&self.source[self.comment.range])
.field("kind", &self.comment.kind)
.field(
"codes",
&DebugCodes {
source: self.source,
codes: self.comment.codes.as_deref().unwrap_or_default(),
},
)
.finish()
}
}
}