rust/crates/ide_assists/src/handlers/inline_local_variable.rs
2021-03-08 22:19:44 +02:00

730 lines
14 KiB
Rust

use ide_db::{defs::Definition, search::FileReference};
use rustc_hash::FxHashMap;
use syntax::{
ast::{self, AstNode, AstToken},
TextRange,
};
use crate::{
assist_context::{AssistContext, Assists},
AssistId, AssistKind,
};
// Assist: inline_local_variable
//
// Inlines local variable.
//
// ```
// fn main() {
// let x$0 = 1 + 2;
// x * 4;
// }
// ```
// ->
// ```
// fn main() {
// (1 + 2) * 4;
// }
// ```
pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
let let_stmt = ctx.find_node_at_offset::<ast::LetStmt>()?;
let bind_pat = match let_stmt.pat()? {
ast::Pat::IdentPat(pat) => pat,
_ => return None,
};
if bind_pat.mut_token().is_some() {
cov_mark::hit!(test_not_inline_mut_variable);
return None;
}
if !bind_pat.syntax().text_range().contains_inclusive(ctx.offset()) {
cov_mark::hit!(not_applicable_outside_of_bind_pat);
return None;
}
let initializer_expr = let_stmt.initializer()?;
let def = ctx.sema.to_def(&bind_pat)?;
let def = Definition::Local(def);
let usages = def.usages(&ctx.sema).all();
if usages.is_empty() {
cov_mark::hit!(test_not_applicable_if_variable_unused);
return None;
};
let delete_range = if let Some(whitespace) = let_stmt
.syntax()
.next_sibling_or_token()
.and_then(|it| ast::Whitespace::cast(it.as_token()?.clone()))
{
TextRange::new(
let_stmt.syntax().text_range().start(),
whitespace.syntax().text_range().end(),
)
} else {
let_stmt.syntax().text_range()
};
let wrap_in_parens = usages
.references
.iter()
.map(|(&file_id, refs)| {
refs.iter()
.map(|&FileReference { range, .. }| {
let usage_node = ctx
.covering_node_for_range(range)
.ancestors()
.find_map(ast::PathExpr::cast)?;
let usage_parent_option =
usage_node.syntax().parent().and_then(ast::Expr::cast);
let usage_parent = match usage_parent_option {
Some(u) => u,
None => return Some(false),
};
Some(!matches!(
(&initializer_expr, usage_parent),
(ast::Expr::CallExpr(_), _)
| (ast::Expr::IndexExpr(_), _)
| (ast::Expr::MethodCallExpr(_), _)
| (ast::Expr::FieldExpr(_), _)
| (ast::Expr::TryExpr(_), _)
| (ast::Expr::RefExpr(_), _)
| (ast::Expr::Literal(_), _)
| (ast::Expr::TupleExpr(_), _)
| (ast::Expr::ArrayExpr(_), _)
| (ast::Expr::ParenExpr(_), _)
| (ast::Expr::PathExpr(_), _)
| (ast::Expr::BlockExpr(_), _)
| (ast::Expr::EffectExpr(_), _)
| (_, ast::Expr::CallExpr(_))
| (_, ast::Expr::TupleExpr(_))
| (_, ast::Expr::ArrayExpr(_))
| (_, ast::Expr::ParenExpr(_))
| (_, ast::Expr::ForExpr(_))
| (_, ast::Expr::WhileExpr(_))
| (_, ast::Expr::BreakExpr(_))
| (_, ast::Expr::ReturnExpr(_))
| (_, ast::Expr::MatchExpr(_))
))
})
.collect::<Option<_>>()
.map(|b| (file_id, b))
})
.collect::<Option<FxHashMap<_, Vec<_>>>>()?;
let init_str = initializer_expr.syntax().text().to_string();
let init_in_paren = format!("({})", &init_str);
let target = bind_pat.syntax().text_range();
acc.add(
AssistId("inline_local_variable", AssistKind::RefactorInline),
"Inline variable",
target,
move |builder| {
builder.delete(delete_range);
for (file_id, references) in usages.references {
for (&should_wrap, reference) in wrap_in_parens[&file_id].iter().zip(references) {
let replacement =
if should_wrap { init_in_paren.clone() } else { init_str.clone() };
match reference.name.as_name_ref() {
Some(name_ref)
if ast::RecordExprField::for_field_name(name_ref).is_some() =>
{
cov_mark::hit!(inline_field_shorthand);
builder.insert(reference.range.end(), format!(": {}", replacement));
}
_ => builder.replace(reference.range, replacement),
}
}
}
},
)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_assist, check_assist_not_applicable};
use super::*;
#[test]
fn test_inline_let_bind_literal_expr() {
check_assist(
inline_local_variable,
r"
fn bar(a: usize) {}
fn foo() {
let a$0 = 1;
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn bar(a: usize) {}
fn foo() {
1 + 1;
if 1 > 10 {
}
while 1 > 10 {
}
let b = 1 * 10;
bar(1);
}",
);
}
#[test]
fn test_inline_let_bind_bin_expr() {
check_assist(
inline_local_variable,
r"
fn bar(a: usize) {}
fn foo() {
let a$0 = 1 + 1;
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn bar(a: usize) {}
fn foo() {
(1 + 1) + 1;
if (1 + 1) > 10 {
}
while (1 + 1) > 10 {
}
let b = (1 + 1) * 10;
bar(1 + 1);
}",
);
}
#[test]
fn test_inline_let_bind_function_call_expr() {
check_assist(
inline_local_variable,
r"
fn bar(a: usize) {}
fn foo() {
let a$0 = bar(1);
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn bar(a: usize) {}
fn foo() {
bar(1) + 1;
if bar(1) > 10 {
}
while bar(1) > 10 {
}
let b = bar(1) * 10;
bar(bar(1));
}",
);
}
#[test]
fn test_inline_let_bind_cast_expr() {
check_assist(
inline_local_variable,
r"
fn bar(a: usize): usize { a }
fn foo() {
let a$0 = bar(1) as u64;
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn bar(a: usize): usize { a }
fn foo() {
(bar(1) as u64) + 1;
if (bar(1) as u64) > 10 {
}
while (bar(1) as u64) > 10 {
}
let b = (bar(1) as u64) * 10;
bar(bar(1) as u64);
}",
);
}
#[test]
fn test_inline_let_bind_block_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = { 10 + 1 };
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn foo() {
{ 10 + 1 } + 1;
if { 10 + 1 } > 10 {
}
while { 10 + 1 } > 10 {
}
let b = { 10 + 1 } * 10;
bar({ 10 + 1 });
}",
);
}
#[test]
fn test_inline_let_bind_paren_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = ( 10 + 1 );
a + 1;
if a > 10 {
}
while a > 10 {
}
let b = a * 10;
bar(a);
}",
r"
fn foo() {
( 10 + 1 ) + 1;
if ( 10 + 1 ) > 10 {
}
while ( 10 + 1 ) > 10 {
}
let b = ( 10 + 1 ) * 10;
bar(( 10 + 1 ));
}",
);
}
#[test]
fn test_not_inline_mut_variable() {
cov_mark::check!(test_not_inline_mut_variable);
check_assist_not_applicable(
inline_local_variable,
r"
fn foo() {
let mut a$0 = 1 + 1;
a + 1;
}",
);
}
#[test]
fn test_call_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = bar(10 + 1);
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let b = bar(10 + 1) * 10;
let c = bar(10 + 1) as usize;
}",
);
}
#[test]
fn test_index_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let x = vec![1, 2, 3];
let a$0 = x[0];
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let x = vec![1, 2, 3];
let b = x[0] * 10;
let c = x[0] as usize;
}",
);
}
#[test]
fn test_method_call_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let bar = vec![1];
let a$0 = bar.len();
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let bar = vec![1];
let b = bar.len() * 10;
let c = bar.len() as usize;
}",
);
}
#[test]
fn test_field_expr() {
check_assist(
inline_local_variable,
r"
struct Bar {
foo: usize
}
fn foo() {
let bar = Bar { foo: 1 };
let a$0 = bar.foo;
let b = a * 10;
let c = a as usize;
}",
r"
struct Bar {
foo: usize
}
fn foo() {
let bar = Bar { foo: 1 };
let b = bar.foo * 10;
let c = bar.foo as usize;
}",
);
}
#[test]
fn test_try_expr() {
check_assist(
inline_local_variable,
r"
fn foo() -> Option<usize> {
let bar = Some(1);
let a$0 = bar?;
let b = a * 10;
let c = a as usize;
None
}",
r"
fn foo() -> Option<usize> {
let bar = Some(1);
let b = bar? * 10;
let c = bar? as usize;
None
}",
);
}
#[test]
fn test_ref_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let bar = 10;
let a$0 = &bar;
let b = a * 10;
}",
r"
fn foo() {
let bar = 10;
let b = &bar * 10;
}",
);
}
#[test]
fn test_tuple_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = (10, 20);
let b = a[0];
}",
r"
fn foo() {
let b = (10, 20)[0];
}",
);
}
#[test]
fn test_array_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = [1, 2, 3];
let b = a.len();
}",
r"
fn foo() {
let b = [1, 2, 3].len();
}",
);
}
#[test]
fn test_paren() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = (10 + 20);
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let b = (10 + 20) * 10;
let c = (10 + 20) as usize;
}",
);
}
#[test]
fn test_path_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let d = 10;
let a$0 = d;
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let d = 10;
let b = d * 10;
let c = d as usize;
}",
);
}
#[test]
fn test_block_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = { 10 };
let b = a * 10;
let c = a as usize;
}",
r"
fn foo() {
let b = { 10 } * 10;
let c = { 10 } as usize;
}",
);
}
#[test]
fn test_used_in_different_expr1() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = 10 + 20;
let b = a * 10;
let c = (a, 20);
let d = [a, 10];
let e = (a);
}",
r"
fn foo() {
let b = (10 + 20) * 10;
let c = (10 + 20, 20);
let d = [10 + 20, 10];
let e = (10 + 20);
}",
);
}
#[test]
fn test_used_in_for_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = vec![10, 20];
for i in a {}
}",
r"
fn foo() {
for i in vec![10, 20] {}
}",
);
}
#[test]
fn test_used_in_while_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = 1 > 0;
while a {}
}",
r"
fn foo() {
while 1 > 0 {}
}",
);
}
#[test]
fn test_used_in_break_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = 1 + 1;
loop {
break a;
}
}",
r"
fn foo() {
loop {
break 1 + 1;
}
}",
);
}
#[test]
fn test_used_in_return_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = 1 > 0;
return a;
}",
r"
fn foo() {
return 1 > 0;
}",
);
}
#[test]
fn test_used_in_match_expr() {
check_assist(
inline_local_variable,
r"
fn foo() {
let a$0 = 1 > 0;
match a {}
}",
r"
fn foo() {
match 1 > 0 {}
}",
);
}
#[test]
fn inline_field_shorthand() {
cov_mark::check!(inline_field_shorthand);
check_assist(
inline_local_variable,
r"
struct S { foo: i32}
fn main() {
let $0foo = 92;
S { foo }
}
",
r"
struct S { foo: i32}
fn main() {
S { foo: 92 }
}
",
);
}
#[test]
fn test_not_applicable_if_variable_unused() {
cov_mark::check!(test_not_applicable_if_variable_unused);
check_assist_not_applicable(
inline_local_variable,
r"
fn foo() {
let $0a = 0;
}
",
)
}
#[test]
fn not_applicable_outside_of_bind_pat() {
cov_mark::check!(not_applicable_outside_of_bind_pat);
check_assist_not_applicable(
inline_local_variable,
r"
fn main() {
let x = $01 + 2;
x * 4;
}
",
)
}
}