use syntax::{
- ast::{edit::AstNodeEdit, make, AstNode, BlockExpr, Expr, IfExpr, MatchArm},
+ ast::{edit::AstNodeEdit, make, AstNode, BlockExpr, ElseBranch, Expr, IfExpr, MatchArm, Pat},
SyntaxKind::WHITESPACE,
};
}
let space_before_guard = guard.syntax().prev_sibling_or_token();
- // FIXME: support `if let` guards too
- if guard.let_token().is_some() {
- return None;
- }
- let guard_condition = guard.expr()?;
+ let guard_condition = guard.condition()?;
let arm_expr = match_arm.expr()?;
- let if_expr = make::expr_if(
- make::condition(guard_condition, None),
- make::block_expr(None, Some(arm_expr.clone())),
- None,
- )
- .indent(arm_expr.indent_level());
+ let if_expr =
+ make::expr_if(guard_condition, make::block_expr(None, Some(arm_expr.clone())), None)
+ .indent(arm_expr.indent_level());
let target = guard.syntax().text_range();
acc.add(
}
})?;
let replace_node = replace_node.unwrap_or_else(|| if_expr.syntax().clone());
-
- let cond = if_expr.condition()?;
- let then_block = if_expr.then_branch()?;
-
- // Not support if with else branch
- if if_expr.else_branch().is_some() {
- return None;
- }
- // Not support moving if let to arm guard
- if cond.is_pattern_cond() {
- return None;
- }
-
- let buf = format!(" if {}", cond.syntax().text());
+ let needs_dedent = replace_node != *if_expr.syntax();
+ let (conds_blocks, tail) = parse_if_chain(if_expr)?;
acc.add(
AssistId("move_arm_cond_to_match_guard", AssistKind::RefactorRewrite),
"Move condition to match guard",
replace_node.text_range(),
|edit| {
- let then_only_expr = then_block.statements().next().is_none();
+ edit.delete(match_arm.syntax().text_range());
+ // Dedent if if_expr is in a BlockExpr
+ let dedent = if needs_dedent {
+ cov_mark::hit!(move_guard_ifelse_in_block);
+ 1
+ } else {
+ 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 = " ".repeat(indent_level.0 as _);
- match &then_block.tail_expr() {
- Some(then_expr) if then_only_expr => {
- edit.replace(replace_node.text_range(), then_expr.syntax().text())
+ let mut first = true;
+ for (cond, block) in conds_blocks {
+ if !first {
+ edit.insert(then_arm_end, format!("\n{}", spaces));
+ } else {
+ first = false;
}
- _ if replace_node != *if_expr.syntax() => {
- // Dedent because if_expr is in a BlockExpr
- let replace_with = then_block.dedent(1.into()).syntax().text();
- edit.replace(replace_node.text_range(), replace_with)
+ let guard = format!("{} if {} => ", match_pat, cond.syntax().text());
+ 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)
+ }
+ }
+ }
+ if let Some(e) = 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() {
+ 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, ",");
+ }
+ _ => {
+ let to_insert = e.dedent(dedent.into()).syntax().text();
+ edit.insert(then_arm_end, to_insert)
+ }
+ }
+ } else {
+ // There's no else branch. Add a pattern without guard, unless the following match
+ // arm is `_ => ...`
+ cov_mark::hit!(move_guard_ifelse_notail);
+ match match_arm.syntax().next_sibling().and_then(MatchArm::cast) {
+ Some(next_arm)
+ if matches!(next_arm.pat(), Some(Pat::WildcardPat(_)))
+ && next_arm.guard().is_none() =>
+ {
+ cov_mark::hit!(move_guard_ifelse_has_wildcard);
+ }
+ _ => edit.insert(then_arm_end, format!("\n{}{} => {{}}", spaces, match_pat)),
}
- _ => edit.replace(replace_node.text_range(), then_block.syntax().text()),
}
-
- edit.insert(match_pat.syntax().text_range().end(), buf);
},
)
}
+// Parses an if-else-if chain to get the conditions and the then branches until we encounter an else
+// branch or the end.
+fn parse_if_chain(if_expr: IfExpr) -> Option<(Vec<(Expr, BlockExpr)>, Option<BlockExpr>)> {
+ let mut conds_blocks = Vec::new();
+ let mut curr_if = if_expr;
+ let tail = loop {
+ let cond = curr_if.condition()?;
+ conds_blocks.push((cond, curr_if.then_branch()?));
+ match curr_if.else_branch() {
+ Some(ElseBranch::IfExpr(e)) => {
+ curr_if = e;
+ }
+ Some(ElseBranch::Block(b)) => {
+ break Some(b);
+ }
+ None => break None,
+ }
+ };
+ Some((conds_blocks, tail))
+}
+
#[cfg(test)]
mod tests {
use super::*;
);
}
+ #[test]
+ fn move_let_guard_to_arm_body_works() {
+ check_assist(
+ move_guard_to_arm_body,
+ r#"
+fn main() {
+ match 92 {
+ x $0if (let 1 = x) => false,
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x => if (let 1 = x) {
+ false
+ },
+ _ => true
+ }
+}
+"#,
+ );
+ }
+
#[test]
fn move_guard_to_arm_body_works_complex_match() {
check_assist(
#[test]
fn move_arm_cond_in_block_to_match_guard_works() {
+ cov_mark::check!(move_guard_ifelse_has_wildcard);
check_assist(
move_arm_cond_to_match_guard,
r#"
}
#[test]
- fn move_arm_cond_to_match_guard_if_let_not_works() {
- check_assist_not_applicable(
+ fn move_arm_cond_in_block_to_match_guard_no_wildcard_works() {
+ cov_mark::check_count!(move_guard_ifelse_has_wildcard, 0);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => {
+ $0if x > 10 {
+ false
+ }
+ }
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => {}
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn move_arm_cond_in_block_to_match_guard_wildcard_guard_works() {
+ cov_mark::check_count!(move_guard_ifelse_has_wildcard, 0);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => {
+ $0if x > 10 {
+ false
+ }
+ }
+ _ if x > 10 => true,
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => {}
+ _ if x > 10 => true,
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn move_arm_cond_in_block_to_match_guard_add_comma_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => {
+ $0if x > 10 {
+ false
+ }
+ }
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ _ => true
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_if_let_works() {
+ check_assist(
move_arm_cond_to_match_guard,
r#"
fn main() {
match 92 {
- x => if let 62 = x { $0false },
+ x => if let 62 = x && true { $0false },
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if let 62 = x && true => false,
_ => true
}
}
r#"
fn main() {
match 92 {
- x if x > 10 => { },
+ x if x > 10 => { }
_ => true
}
}
x if x > 10 => {
92;
false
- },
+ }
_ => true
}
}
_ => true
}
}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => if x > 10 {$0
+ false
+ } else {
+ true
+ }
+ _ => true,
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => true,
+ _ => true,
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_block_works() {
+ cov_mark::check!(move_guard_ifelse_expr_only);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => {
+ if x > 10 {$0
+ false
+ } else {
+ true
+ }
+ }
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => true,
+ _ => true
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_else_if_empty_body_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => if x > 10 { $0 } else { },
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => { }
+ x => { }
+ _ => true
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_multiline_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => if x > 10 {
+ 92;$0
+ false
+ } else {
+ true
+ }
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => {
+ 92;
+ false
+ }
+ x => true,
+ _ => true
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_multiline_else_works() {
+ cov_mark::check!(move_guard_ifelse_else_block);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => if x > 10 {$0
+ false
+ } else {
+ 42;
+ true
+ }
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => {
+ 42;
+ true
+ }
+ _ => true
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_multiline_else_block_works() {
+ cov_mark::check!(move_guard_ifelse_in_block);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ x => {
+ if x > 10 {$0
+ false
+ } else {
+ 42;
+ true
+ }
+ }
+ _ => true
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ x if x > 10 => false,
+ x => {
+ 42;
+ true
+ }
+ _ => true
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_last_arm_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x => {
+ if x > 10 {$0
+ false
+ } else {
+ 92;
+ true
+ }
+ }
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x if x > 10 => false,
+ x => {
+ 92;
+ true
+ }
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_with_else_comma_works() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x => if x > 10 {$0
+ false
+ } else {
+ 92;
+ true
+ },
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x if x > 10 => false,
+ x => {
+ 92;
+ true
+ }
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_elseif() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x => if x > 10 {$0
+ false
+ } else if x > 5 {
+ true
+ } else if x > 4 {
+ false
+ } else {
+ true
+ },
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x if x > 10 => false,
+ x if x > 5 => true,
+ x if x > 4 => false,
+ x => true,
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_elseif_in_block() {
+ cov_mark::check!(move_guard_ifelse_in_block);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x => {
+ if x > 10 {$0
+ false
+ } else if x > 5 {
+ true
+ } else if x > 4 {
+ false
+ } else {
+ true
+ }
+ }
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => true,
+ x if x > 10 => false,
+ x if x > 5 => true,
+ x if x > 4 => false,
+ x => true,
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_elseif_chain() {
+ cov_mark::check!(move_guard_ifelse_else_tail);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x => if x > 10 {$0
+ 1
+ } else if x > 5 {
+ 2
+ } else if x > 3 {
+ 42;
+ 3
+ } else {
+ 4
+ },
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x if x > 10 => 1,
+ x if x > 5 => 2,
+ x if x > 3 => {
+ 42;
+ 3
+ }
+ x => 4,
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_elseif_iflet() {
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x => if x > 10 {$0
+ 1
+ } else if x > 5 {
+ 2
+ } else if let 4 = 4 {
+ 42;
+ 3
+ } else {
+ 4
+ },
+ }
+}"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x if x > 10 => 1,
+ x if x > 5 => 2,
+ x if let 4 = 4 => {
+ 42;
+ 3
+ }
+ x => 4,
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn move_arm_cond_to_match_guard_elseif_notail() {
+ cov_mark::check!(move_guard_ifelse_notail);
+ check_assist(
+ move_arm_cond_to_match_guard,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x => if x > 10 {$0
+ 1
+ } else if x > 5 {
+ 2
+ } else if x > 4 {
+ 42;
+ 3
+ },
+ }
+}
+"#,
+ r#"
+fn main() {
+ match 92 {
+ 3 => 0,
+ x if x > 10 => 1,
+ x if x > 5 => 2,
+ x if x > 4 => {
+ 42;
+ 3
+ }
+ x => {}
+ }
+}
"#,
)
}
projects / rust.git / blobdiff