Unnamed repository; edit this file 'description' to name the repository.
-rw-r--r--crates/ide-assists/src/handlers/merge_nested_if.rs230
-rw-r--r--crates/ide-assists/src/lib.rs2
-rw-r--r--crates/ide-assists/src/tests/generated.rs15
3 files changed, 247 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/merge_nested_if.rs b/crates/ide-assists/src/handlers/merge_nested_if.rs
new file mode 100644
index 0000000000..af99d6fdef
--- /dev/null
+++ b/crates/ide-assists/src/handlers/merge_nested_if.rs
@@ -0,0 +1,230 @@
+use ide_db::syntax_helpers::node_ext::is_pattern_cond;
+use syntax::{
+ ast::{self, AstNode, BinaryOp},
+ T,
+};
+
+use crate::{
+ assist_context::{AssistContext, Assists},
+ AssistId, AssistKind,
+};
+/// Assist: merge_nested_if
+///
+/// This transforms if expressions of the form `if x { if y {A} }` into `if x && y {A}`
+/// This assist can only be applied with the cursor on `if`.
+///
+/// ```
+/// fn main() {
+/// i$0f x == 3 { if y == 4 { 1 } }
+/// }
+/// ```
+/// ->
+/// ```
+/// fn main() {
+/// if x == 3 && y == 4 { 1 }
+/// }
+/// ```
+pub(crate) fn merge_nested_if(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
+ let if_keyword = ctx.find_token_syntax_at_offset(T![if])?;
+ let expr = ast::IfExpr::cast(if_keyword.parent()?)?;
+ let if_range = if_keyword.text_range();
+ let cursor_in_range = if_range.contains_range(ctx.selection_trimmed());
+ if !cursor_in_range {
+ return None;
+ }
+
+ //should not apply to if with else branch.
+ if expr.else_branch().is_some() {
+ return None;
+ }
+
+ let cond = expr.condition()?;
+ let cond_range = cond.syntax().text_range();
+ //should not apply for if-let
+ if is_pattern_cond(cond.clone()) {
+ return None;
+ }
+
+ //check if the then branch is a nested if
+ let then_branch = expr.then_branch()?;
+
+ let nested_if_to_merge = then_branch.syntax().descendants().find_map(ast::IfExpr::cast)?;
+ // should not apply to nested if with else branch.
+ if nested_if_to_merge.else_branch().is_some() {
+ return None;
+ }
+ let nested_if_cond = nested_if_to_merge.condition()?;
+ if is_pattern_cond(nested_if_cond.clone()) {
+ return None;
+ }
+
+ let nested_if_then_branch = nested_if_to_merge.then_branch()?;
+ let then_branch_range = then_branch.syntax().text_range();
+
+ acc.add(
+ AssistId("merge_nested_if", AssistKind::RefactorRewrite),
+ "Merge nested if",
+ if_range,
+ |edit| {
+ let cond_text = if has_logic_op_or(&cond) {
+ format!("({})", cond.syntax().text())
+ } else {
+ cond.syntax().text().to_string()
+ };
+
+ let nested_if_cond_text = if has_logic_op_or(&nested_if_cond) {
+ format!("({})", nested_if_cond.syntax().text())
+ } else {
+ nested_if_cond.syntax().text().to_string()
+ };
+
+ let replace_cond = format!("{} && {}", cond_text, nested_if_cond_text);
+
+ edit.replace(cond_range, replace_cond);
+ edit.replace(then_branch_range, nested_if_then_branch.syntax().text());
+ },
+ )
+}
+
+/// Returns whether the given if condition has logical operators.
+fn has_logic_op_or(expr: &ast::Expr) -> bool {
+ match expr {
+ ast::Expr::BinExpr(bin_expr) => {
+ if let Some(kind) = bin_expr.op_kind() {
+ matches!(kind, BinaryOp::LogicOp(ast::LogicOp::Or))
+ } else {
+ false
+ }
+ }
+ _ => false,
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use crate::tests::{check_assist, check_assist_not_applicable};
+
+ #[test]
+ fn merge_nested_if_test1() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 { if y == 4 { 1 } } }",
+ "fn f() { if x == 3 && y == 4 { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test2() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 || y == 1 { if z == 4 { 1 } } }",
+ "fn f() { if (x == 3 || y == 1) && z == 4 { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test3() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 && y == 1 { if z == 4 { 1 } } }",
+ "fn f() { if x == 3 && y == 1 && z == 4 { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test4() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 && y == 1 { if z == 4 && q == 3 { 1 } } }",
+ "fn f() { if x == 3 && y == 1 && z == 4 && q == 3 { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test5() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 && y == 1 { if z == 4 || q == 3 { 1 } } }",
+ "fn f() { if x == 3 && y == 1 && (z == 4 || q == 3) { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test6() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 || y == 1 { if z == 4 || q == 3 { 1 } } }",
+ "fn f() { if (x == 3 || y == 1) && (z == 4 || q == 3) { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_test7() {
+ check_assist(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 || y == 1 { if z == 4 && q == 3 { 1 } } }",
+ "fn f() { if (x == 3 || y == 1) && z == 4 && q == 3 { 1 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_to_if_with_else_branch() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 { if y == 4 { 1 } } else { 2 } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_to_nested_if_with_else_branch() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 { if y == 4 { 1 } else { 2 } } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_to_if_let() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f let Some(x) = y { if x == 4 { 1 } } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_to_nested_if_let() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f y == 0 { if let Some(x) = y { 1 } } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_to_if_with_else_branch_and_nested_if() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f x == 3 { if y == 4 { 1 } } else { if z == 5 { 2 } } }",
+ )
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_with_cursor_not_on_if() {
+ check_assist_not_applicable(merge_nested_if, "fn f() { if $0x==0 { if y == 3 { 1 } } }")
+ }
+
+ #[test]
+ fn merge_nested_if_do_not_apply_with_mulpiple_if() {
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f x == 0 { if y == 3 { 1 } else if y == 4 { 2 } } }",
+ )
+ }
+ #[test]
+ fn merge_nested_if_do_not_apply_with_not_only_has_nested_if(){
+ check_assist_not_applicable(
+ merge_nested_if,
+ "fn f() { i$0f x == 0 { if y == 3 { foo(); } foo(); } }",
+ )
+ }
+}
diff --git a/crates/ide-assists/src/lib.rs b/crates/ide-assists/src/lib.rs
index 1e4d1c94f5..1eb4903ab2 100644
--- a/crates/ide-assists/src/lib.rs
+++ b/crates/ide-assists/src/lib.rs
@@ -217,6 +217,7 @@ mod handlers {
mod unqualify_method_call;
mod wrap_return_type_in_result;
mod into_to_qualified_from;
+ mod merge_nested_if;
pub(crate) fn all() -> &'static [Handler] {
&[
@@ -291,6 +292,7 @@ mod handlers {
invert_if::invert_if,
merge_imports::merge_imports,
merge_match_arms::merge_match_arms,
+ merge_nested_if::merge_nested_if,
move_bounds::move_bounds_to_where_clause,
move_const_to_impl::move_const_to_impl,
move_guard::move_arm_cond_to_match_guard,
diff --git a/crates/ide-assists/src/tests/generated.rs b/crates/ide-assists/src/tests/generated.rs
index da5822bba9..79958a2292 100644
--- a/crates/ide-assists/src/tests/generated.rs
+++ b/crates/ide-assists/src/tests/generated.rs
@@ -2052,6 +2052,21 @@ fn handle(action: Action) {
}
#[test]
+fn doctest_merge_nested_if() {
+ check_doc_test(
+ "merge_nested_if",
+ r#####"
+ fn main() {
+ i$0f x == 3 { if y == 4 { 1 } }
+ }"#####,
+ r#####"
+ fn main() {
+ if x == 3 && y == 4 { 1 }
+ }"#####,
+ )
+}
+
+#[test]
fn doctest_move_arm_cond_to_match_guard() {
check_doc_test(
"move_arm_cond_to_match_guard",