Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

refactor(linter): use regex parser in eslint/no-regex-spaces #5952

Merged
merged 1 commit into from
Sep 22, 2024
Merged

refactor(linter): use regex parser in eslint/no-regex-spaces #5952

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
176 changes: 98 additions & 78 deletions crates/oxc_linter/src/rules/eslint/no_regex_spaces.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,10 +1,16 @@
use oxc_allocator::Vec;
use aho_corasick::AhoCorasick;
use lazy_static::lazy_static;
use oxc_allocator::{Allocator, Vec};
use oxc_ast::{
ast::{Argument, CallExpression, NewExpression, RegExpLiteral},
AstKind,
};
use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_regular_expression::{
ast::{Alternative, Disjunction, Pattern, Term},
Parser, ParserOptions,
};
use oxc_span::Span;

use crate::{context::LintContext, rule::Rule, AstNode};
Expand Down Expand Up @@ -38,8 +44,14 @@ declare_oxc_lint!(
/// ```
NoRegexSpaces,
restriction,
pending // TODO: This is somewhat autofixable, but the fixer does not exist yet.
);

lazy_static! {
static ref DOUBLE_SPACE: AhoCorasick =
AhoCorasick::new([" "]).expect("no-regex-spaces: Unable to build AhoCorasick");
}

impl Rule for NoRegexSpaces {
fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
match node.kind() {
Expand Down Expand Up @@ -70,18 +82,12 @@ impl NoRegexSpaces {
fn find_literal_to_report(literal: &RegExpLiteral, ctx: &LintContext) -> Option<Span> {
let pattern_text = literal.regex.pattern.source_text(ctx.source_text());
let pattern_text = pattern_text.as_ref();
if Self::has_exempted_char_class(pattern_text) {
if !Self::has_double_space(pattern_text) {
return None;
}

if let Some((idx_start, idx_end)) = Self::find_consecutive_spaces_indices(pattern_text) {
let start = literal.span.start + u32::try_from(idx_start).unwrap() + 1;
let end = literal.span.start + u32::try_from(idx_end).unwrap() + 2;

return Some(Span::new(start, end));
}

None
let pattern = literal.regex.pattern.as_pattern()?;
Self::find_consecutive_spaces(pattern)
}

fn find_expr_to_report(args: &Vec<'_, Argument<'_>>) -> Option<Span> {
Expand All @@ -91,72 +97,60 @@ impl NoRegexSpaces {
}
}

if let Some(Argument::StringLiteral(pattern)) = args.first() {
if Self::has_exempted_char_class(&pattern.value) {
return None; // skip spaces inside char class, e.g. RegExp('[ ]')
}

if let Some((idx_start, idx_end)) =
Self::find_consecutive_spaces_indices(&pattern.value)
{
let start = pattern.span.start + u32::try_from(idx_start).unwrap() + 1;
let end = pattern.span.start + u32::try_from(idx_end).unwrap() + 2;

return Some(Span::new(start, end));
}
let Some(Argument::StringLiteral(pattern)) = args.first() else {
return None;
};
if !Self::has_double_space(&pattern.value) {
return None;
}

None
}
let alloc = Allocator::default();
let pattern_with_slashes = format!("/{}/", &pattern.value);
let parser = Parser::new(&alloc, pattern_with_slashes.as_str(), ParserOptions::default());
let regex = parser.parse().ok()?;

fn find_consecutive_spaces_indices(input: &str) -> Option<(usize, usize)> {
let mut consecutive_spaces = 0;
let mut start: Option<usize> = None;
let mut inside_square_brackets: usize = 0;

for (cur_idx, char) in input.char_indices() {
if char == '[' {
inside_square_brackets += 1;
} else if char == ']' {
inside_square_brackets = inside_square_brackets.saturating_sub(1);
}
Self::find_consecutive_spaces(&regex.pattern)
.map(|span| Span::new(span.start + pattern.span.start, span.end + pattern.span.start))
}

if char != ' ' || inside_square_brackets > 0 {
// ignore spaces inside char class, including nested ones
consecutive_spaces = 0;
start = None;
continue;
fn find_consecutive_spaces(pattern: &Pattern) -> Option<Span> {
let mut last_space_span: Option<Span> = None;
let mut in_quantifier = false;
visit_terms(pattern, &mut |term| {
if let Term::Quantifier(_) = term {
in_quantifier = true;
return;
}

if start.is_none() {
start = Some(cur_idx);
let Term::Character(ch) = term else {
return;
};
if in_quantifier {
in_quantifier = false;
return;
}

consecutive_spaces += 1;

if consecutive_spaces < 2 {
continue;
if ch.value != u32::from(b' ') {
return;
}

// 2 or more consecutive spaces

if let Some(next_char) = input.chars().nth(cur_idx + 1) {
if next_char == ' ' {
continue; // keep collecting spaces
if let Some(ref mut space_span) = last_space_span {
// If this is consecutive with the last space, extend it
if space_span.end == ch.span.start {
space_span.end = ch.span.end;
}

if "+*{?".contains(next_char) && consecutive_spaces == 2 {
continue; // ignore 2 consecutive spaces before quantifier
// If it is not consecutive, and the last space is only one space, move it up
else if space_span.size() == 1 {
last_space_span.replace(ch.span);
}

return Some((start.unwrap(), cur_idx));
} else {
last_space_span = Some(ch.span);
}
});

// end of string
return Some((start.unwrap(), cur_idx));
// return None if last_space_span length is only 1
if last_space_span.is_some_and(|span| span.size() > 1) {
last_space_span
} else {
None
}

None
}

fn is_regexp_new_expression(expr: &NewExpression<'_>) -> bool {
Expand All @@ -167,23 +161,47 @@ impl NoRegexSpaces {
expr.callee.is_specific_id("RegExp") && expr.arguments.len() > 0
}

/// Whether the input has a character class but no consecutive spaces
/// outside the character class.
fn has_exempted_char_class(input: &str) -> bool {
let mut inside_class = false;
// For skipping if there aren't any consecutive spaces in the source, to avoid reporting cases
// where the space is explicitly escaped, like: `RegExp(' \ ')``.
fn has_double_space(input: &str) -> bool {
DOUBLE_SPACE.is_match(input)
}
}

for (i, c) in input.chars().enumerate() {
match c {
'[' => inside_class = true,
']' => inside_class = false,
' ' if input.chars().nth(i + 1) == Some(' ') && !inside_class => {
return false;
}
_ => {}
/// Calls the given closure on every [`Term`] in the [`Pattern`].
fn visit_terms<'a, F: FnMut(&'a Term<'a>)>(pattern: &'a Pattern, f: &mut F) {
visit_terms_disjunction(&pattern.body, f);
}

/// Calls the given closure on every [`Term`] in the [`Disjunction`].
fn visit_terms_disjunction<'a, F: FnMut(&'a Term<'a>)>(disjunction: &'a Disjunction, f: &mut F) {
for alternative in &disjunction.body {
visit_terms_alternative(alternative, f);
}
}

/// Calls the given closure on every [`Term`] in the [`Alternative`].
fn visit_terms_alternative<'a, F: FnMut(&'a Term<'a>)>(alternative: &'a Alternative, f: &mut F) {
for term in &alternative.body {
match term {
Term::LookAroundAssertion(lookaround) => {
f(term);
visit_terms_disjunction(&lookaround.body, f);
}
Term::Quantifier(quant) => {
f(term);
f(&quant.body);
}
Term::CapturingGroup(group) => {
f(term);
visit_terms_disjunction(&group.body, f);
}
Term::IgnoreGroup(group) => {
f(term);
visit_terms_disjunction(&group.body, f);
}
_ => f(term),
}

true
}
}

Expand All @@ -208,6 +226,7 @@ fn test() {
"var foo = / */;",
"var foo = / {2}/;",
"var foo = / {2}/v;",
"var foo = / /;",
r"var foo = /bar \\ baz/;",
r"var foo = /bar\\ \\ baz/;",
r"var foo = /bar \\u0020 baz/;",
Expand All @@ -234,6 +253,7 @@ fn test() {
];

let fail = vec![
"var foo = / /;",
"var foo = /bar baz/;",
"var foo = /bar baz/;",
"var foo = / a b c d /;",
Expand Down
19 changes: 13 additions & 6 deletions crates/oxc_linter/src/snapshots/no_regex_spaces.snap
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,13 @@
---
source: crates/oxc_linter/src/tester.rs
---
⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:12]
1 │ var foo = / /;
· ──
╰────
help: Use a quantifier, e.g. {2}

⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:15]
1 │ var foo = /bar baz/;
Expand Down Expand Up @@ -46,28 +53,28 @@ source: crates/oxc_linter/src/tester.rs
⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:15]
1 │ var foo = /bar {3}baz/;
· ───
· ──
╰────
help: Use a quantifier, e.g. {2}

⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:15]
1 │ var foo = /bar ?baz/;
· ────
· ───
╰────
help: Use a quantifier, e.g. {2}

⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:26]
1 │ var foo = new RegExp('bar *baz')
· ───
DonIsaac marked this conversation as resolved.
Show resolved Hide resolved
· ──
╰────
help: Use a quantifier, e.g. {2}

⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:22]
1 │ var foo = RegExp('bar +baz')
· ───
· ──
╰────
help: Use a quantifier, e.g. {2}

Expand Down Expand Up @@ -170,8 +177,8 @@ source: crates/oxc_linter/src/tester.rs
help: Use a quantifier, e.g. {2}

⚠ eslint(no-regex-spaces): Spaces are hard to count.
╭─[no_regex_spaces.tsx:1:35]
╭─[no_regex_spaces.tsx:1:30]
1 │ var foo = new RegExp('[[ ] ] ', 'v');
· ────
· ────
╰────
help: Use a quantifier, e.g. {2}