Special-case parenthesized and negated expressions in demorgan assist
use syntax::ast::{self, AstNode};
+use test_utils::mark;
use crate::{utils::invert_boolean_expression, AssistContext, AssistId, AssistKind, Assists};
@@ -43,9 +44,36 @@ pub(crate) fn apply_demorgan(acc: &mut Assists, ctx: &AssistContext) -> Option<(
"Apply De Morgan's law",
op_range,
|edit| {
+ let paren_expr = expr.syntax().parent().and_then(|parent| ast::ParenExpr::cast(parent));
+
+ let neg_expr = paren_expr
+ .clone()
+ .and_then(|paren_expr| paren_expr.syntax().parent())
+ .and_then(|parent| ast::PrefixExpr::cast(parent))
+ .and_then(|prefix_expr| {
+ if prefix_expr.op_kind().unwrap() == ast::PrefixOp::Not {
+ Some(prefix_expr)
+ } else {
+ None
+ }
+ });
+
edit.replace(op_range, opposite_op);
+
+ if let Some(paren_expr) = paren_expr {
+ edit.replace(lhs_range, not_lhs.syntax().text());
+ edit.replace(rhs_range, not_rhs.syntax().text());
+ if let Some(neg_expr) = neg_expr {
+ mark::hit!(demorgan_double_negation);
+ edit.replace(neg_expr.op_token().unwrap().text_range(), "");
+ } else {
+ mark::hit!(demorgan_double_parens);
+ edit.replace(paren_expr.l_paren_token().unwrap().text_range(), "!(");
+ }
+ } else {
edit.replace(lhs_range, format!("!({}", not_lhs.syntax().text()));
edit.replace(rhs_range, format!("{})", not_rhs.syntax().text()));
+ }
},
)
}
@@ -62,6 +90,7 @@ fn opposite_logic_op(kind: ast::BinOp) -> Option<&'static str> {
#[cfg(test)]
mod tests {
use ide_db::helpers::FamousDefs;
+ use test_utils::mark;
use super::*;
@@ -156,4 +185,16 @@ fn f() {
fn demorgan_doesnt_apply_with_cursor_not_on_op() {
check_assist_not_applicable(apply_demorgan, "fn f() { $0 !x || !x }")
}
+
+ #[test]
+ fn demorgan_doesnt_double_negation() {
+ mark::check!(demorgan_double_negation);
+ check_assist(apply_demorgan, "fn f() { !(x ||$0 x) }", "fn f() { (!x && !x) }")
+ }
+
+ #[test]
+ fn demorgan_doesnt_double_parens() {
+ mark::check!(demorgan_double_parens);
+ check_assist(apply_demorgan, "fn f() { (x ||$0 x) }", "fn f() { !(!x && !x) }")
+ }
}
