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Merge pull request #21369 from A4-Tacks/migrate-move-guard

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Migrate `move_arm_cond_to_match_guard` assist to use `SyntaxEditor`
This commit is contained in:
Shoyu Vanilla (Flint) 2026-01-04 15:41:17 +00:00 • committed by GitHub
commit b1ed7e6184
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GPG key ID: B5690EEEBB952194
1 changed files with 38 additions and 36 deletions
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74
src/tools/rust-analyzer/crates/ide-assists/src/handlers/move_guard.rs
View file

@ -1,6 +1,11 @@
use itertools::Itertools;
use syntax::{
SyntaxKind::WHITESPACE,
ast::{AstNode, BlockExpr, ElseBranch, Expr, IfExpr, MatchArm, Pat, edit::AstNodeEdit, make},
ast::{
AstNode, BlockExpr, ElseBranch, Expr, IfExpr, MatchArm, Pat, edit::AstNodeEdit, make,
syntax_factory::SyntaxFactory,
},
syntax_editor::Element,
};
use crate::{AssistContext, AssistId, Assists};
@ -131,8 +136,10 @@ pub(crate) fn move_arm_cond_to_match_guard(
AssistId::refactor_rewrite("move_arm_cond_to_match_guard"),
"Move condition to match guard",
replace_node.text_range(),
|edit| {
edit.delete(match_arm.syntax().text_range());
|builder| {
let make = SyntaxFactory::without_mappings();
let mut replace_arms = vec![];
// Dedent if if_expr is in a BlockExpr
let dedent = if needs_dedent {
cov_mark::hit!(move_guard_ifelse_in_block);
@ -141,47 +148,30 @@ pub(crate) fn move_arm_cond_to_match_guard(
cov_mark::hit!(move_guard_ifelse_else_block);
0
};
let then_arm_end = match_arm.syntax().text_range().end();
let indent_level = match_arm.indent_level();
let spaces = indent_level;
let mut first = true;
for (cond, block) in conds_blocks {
if !first {
edit.insert(then_arm_end, format!("\n{spaces}"));
} else {
first = false;
}
let guard = format!("{match_pat} if {cond} => ");
edit.insert(then_arm_end, guard);
let only_expr = block.statements().next().is_none();
match &block.tail_expr() {
Some(then_expr) if only_expr => {
edit.insert(then_arm_end, then_expr.syntax().text());
edit.insert(then_arm_end, ",");
}
_ => {
let to_insert = block.dedent(dedent.into()).syntax().text();
edit.insert(then_arm_end, to_insert)
}
}
let expr = match block.tail_expr() {
Some(then_expr) if only_expr => then_expr,
_ => block.dedent(dedent.into()).into(),
};
let guard = make.match_guard(cond);
let new_arm = make.match_arm(match_pat.clone(), Some(guard), expr);
replace_arms.push(new_arm);
}
if let Some(e) = tail {
if let Some(block) = tail {
cov_mark::hit!(move_guard_ifelse_else_tail);
let guard = format!("\n{spaces}{match_pat} => ");
edit.insert(then_arm_end, guard);
let only_expr = e.statements().next().is_none();
match &e.tail_expr() {
let only_expr = block.statements().next().is_none();
let expr = match block.tail_expr() {
Some(expr) if only_expr => {
cov_mark::hit!(move_guard_ifelse_expr_only);
edit.insert(then_arm_end, expr.syntax().text());
edit.insert(then_arm_end, ",");
expr
}
_ => {
let to_insert = e.dedent(dedent.into()).syntax().text();
edit.insert(then_arm_end, to_insert)
}
}
_ => block.dedent(dedent.into()).into(),
};
let new_arm = make.match_arm(match_pat, None, expr);
replace_arms.push(new_arm);
} else {
// There's no else branch. Add a pattern without guard, unless the following match
// arm is `_ => ...`
@ -193,9 +183,21 @@ pub(crate) fn move_arm_cond_to_match_guard(
{
cov_mark::hit!(move_guard_ifelse_has_wildcard);
}
_ => edit.insert(then_arm_end, format!("\n{spaces}{match_pat} => {{}}")),
_ => {
let block_expr = make.expr_empty_block().into();
replace_arms.push(make.match_arm(match_pat, None, block_expr));
}
}
}
let mut edit = builder.make_editor(match_arm.syntax());
let newline = make.whitespace(&format!("\n{indent_level}"));
let replace_arms = replace_arms.iter().map(|it| it.syntax().syntax_element());
let replace_arms = Itertools::intersperse(replace_arms, newline.syntax_element());
edit.replace_with_many(match_arm.syntax(), replace_arms.collect());
builder.add_file_edits(ctx.vfs_file_id(), edit);
},
)
}