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

feat(minifier): implement folding indexOf and lastIndexOf string fns #6435

Merged
merged 1 commit into from
Oct 12, 2024
Merged

feat(minifier): implement folding indexOf and lastIndexOf string fns #6435

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
114 changes: 93 additions & 21 deletions crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,9 @@
use cow_utils::CowUtils;
use oxc_ast::ast::*;
use oxc_traverse::{Traverse, TraverseCtx};
use string_methods::StringUtils;

mod string_methods;

use crate::CompressorPass;

Expand Down Expand Up @@ -41,25 +44,94 @@ impl PeepholeReplaceKnownMethods {

let Expression::StaticMemberExpression(member) = &call_expr.callee else { return };
if let Expression::StringLiteral(string_lit) = &member.object {
if call_expr.arguments.len() == 0 {
let transformed_value = match member.property.name.as_str() {
"toLowerCase" => Some(
ctx.ast.string_literal(call_expr.span, string_lit.value.cow_to_lowercase()),
),
"toUpperCase" => Some(
ctx.ast.string_literal(call_expr.span, string_lit.value.cow_to_uppercase()),
),
"trim" => Some(ctx.ast.string_literal(call_expr.span, string_lit.value.trim())),
_ => None,
};

if let Some(transformed_value) = transformed_value {
self.changed = true;
*node = ctx.ast.expression_from_string_literal(transformed_value);
#[expect(clippy::match_same_arms)]
let replacement = match member.property.name.as_str() {
"toLowerCase" | "toUpperCase" | "trim" => {
let transformed_value =
match member.property.name.as_str() {
"toLowerCase" => Some(ctx.ast.string_literal(
call_expr.span,
string_lit.value.cow_to_lowercase(),
)),
"toUpperCase" => Some(ctx.ast.string_literal(
call_expr.span,
string_lit.value.cow_to_uppercase(),
)),
"trim" => Some(
ctx.ast.string_literal(call_expr.span, string_lit.value.trim()),
),
_ => None,
};

transformed_value.map(|transformed_value| {
ctx.ast.expression_from_string_literal(transformed_value)
})
}
"indexOf" | "lastIndexOf" => Self::try_fold_string_index_of(
call_expr.span,
call_expr,
member,
string_lit,
ctx,
),
// TODO: Implement the rest of the string methods
"substr" => None,
"substring" | "slice" => None,
"charAt" => None,
"charCodeAt" => None,
"replace" => None,
"replaceAll" => None,
_ => None,
};

if let Some(replacement) = replacement {
self.changed = true;
*node = replacement;
}
}
}

fn try_fold_string_index_of<'a>(
span: Span,
call_expr: &CallExpression<'a>,
member: &StaticMemberExpression<'a>,
string_lit: &StringLiteral<'a>,
ctx: &mut TraverseCtx<'a>,
) -> Option<Expression<'a>> {
let search_value = match call_expr.arguments.first() {
Some(Argument::StringLiteral(string_lit)) => Some(string_lit.value.as_str()),
None => None,
_ => return None,
};

let search_start_index = match call_expr.arguments.get(1) {
Some(Argument::NumericLiteral(numeric_lit)) => Some(numeric_lit.value),
None => None,
_ => return None,
};

let result = if member.property.name.as_str() == "indexOf" {
StringUtils::evaluate_string_index_of(
&string_lit.value,
search_value,
search_start_index,
)
} else {
StringUtils::evaluate_string_last_index_of(
&string_lit.value,
search_value,
search_start_index,
)
};

#[expect(clippy::cast_precision_loss)]
return Some(ctx.ast.expression_from_numeric_literal(ctx.ast.numeric_literal(
span,
result as f64,
result.to_string(),
NumberBase::Decimal,
)));
}
}

/// Port from: <https://github.com/google/closure-compiler/blob/master/test/com/google/javascript/jscomp/PeepholeReplaceKnownMethodsTest.java>
Expand Down Expand Up @@ -88,7 +160,6 @@ mod test {
}

#[test]
#[ignore]
fn test_string_index_of() {
fold("x = 'abcdef'.indexOf('g')", "x = -1");
fold("x = 'abcdef'.indexOf('b')", "x = 1");
Expand All @@ -102,11 +173,12 @@ mod test {

// Both elements must be strings. Don't do anything if either one is not
// string.
fold("x = 'abc1def'.indexOf(1)", "x = 3");
fold("x = 'abcNaNdef'.indexOf(NaN)", "x = 3");
fold("x = 'abcundefineddef'.indexOf(undefined)", "x = 3");
fold("x = 'abcnulldef'.indexOf(null)", "x = 3");
fold("x = 'abctruedef'.indexOf(true)", "x = 3");
// TODO: cast first arg to a string, and fold if possible.
// fold("x = 'abc1def'.indexOf(1)", "x = 3");
// fold("x = 'abcNaNdef'.indexOf(NaN)", "x = 3");
// fold("x = 'abcundefineddef'.indexOf(undefined)", "x = 3");
// fold("x = 'abcnulldef'.indexOf(null)", "x = 3");
// fold("x = 'abctruedef'.indexOf(true)", "x = 3");

// The following test case fails with JSC_PARSE_ERROR. Hence omitted.
// fold_same("x = 1.indexOf('bcd');");
Expand Down
190 changes: 190 additions & 0 deletions crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods/string_methods.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,190 @@
use oxc_syntax::number::ToJsInt32;

pub(super) struct StringUtils;

impl StringUtils {
#[expect(clippy::cast_possible_wrap, clippy::cast_sign_loss)]
pub(super) fn evaluate_string_index_of(
string: &str,
search_value: Option<&str>,
from_index: Option<f64>,
) -> isize {
let from_index = from_index.map_or(0, |x| x.to_js_int_32().max(0)) as usize;
let Some(search_value) = search_value else {
return -1;
};
let result = string.chars().skip(from_index).collect::<String>().find(search_value);
result.map(|index| index + from_index).map_or(-1, |index| index as isize)
}

#[expect(clippy::cast_possible_wrap, clippy::cast_sign_loss)]
pub(super) fn evaluate_string_last_index_of(
string: &str,
search_value: Option<&str>,
from_index: Option<f64>,
) -> isize {
let Some(search_value) = search_value else { return -1 };

let from_index = from_index
.map_or(usize::MAX, |x| x.to_js_int_32().max(0) as usize + search_value.len());

string
.chars()
.take(from_index)
.collect::<String>()
.rfind(search_value)
.map_or(-1, |index| index as isize)
}
}

#[cfg(test)]
mod test {
#[test]
fn test_evaluate_string_index_of() {
use super::StringUtils;

assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(0.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(1.0)),
3
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(4.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(4.1)),
5
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(0.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(-1.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(-1.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("t"), Some(-1.1)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of(
"test test test",
Some("t"),
Some(-1_073_741_825.0)
),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("e"), Some(0.0)),
1
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("s"), Some(0.0)),
2
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(4.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(5.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(6.0)),
10
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(0.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(-1.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("not found"), Some(-1.0)),
-1
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(-1.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of(
"test test test",
Some("test"),
Some(-1_073_741_825.0)
),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("test"), Some(0.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_index_of("test test test", Some("notpresent"), Some(0.0)),
-1
);
assert_eq!(StringUtils::evaluate_string_index_of("test test test", None, Some(0.0)), -1);
}

#[test]
fn test_evaluate_string_last_index_of() {
use super::StringUtils;
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(15.0)),
10
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(14.0)),
10
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(10.0)),
10
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(9.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(6.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(5.0)),
5
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(4.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", Some("test"), Some(0.0)),
0
);
assert_eq!(
StringUtils::evaluate_string_last_index_of(
"test test test",
Some("notpresent"),
Some(0.0)
),
-1
);
assert_eq!(
StringUtils::evaluate_string_last_index_of("test test test", None, Some(1.0)),
-1
);
assert_eq!(StringUtils::evaluate_string_last_index_of("abcdef", Some("b"), None), 1);
}
}