From a70beea9e9c0ffd226708abdb6a2860f7a32be19 Mon Sep 17 00:00:00 2001
From: Wang Ruochen <wrc@ruo-chen.wang>
Date: Mon, 2 May 2022 14:45:31 -0700
Subject: [PATCH] Trigger only when cursor is on else

---
 .../src/handlers/convert_let_else_to_match.rs | 49 ++++++++++++-------
 crates/ide-assists/src/tests/generated.rs     |  2 +-
 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/crates/ide-assists/src/handlers/convert_let_else_to_match.rs b/crates/ide-assists/src/handlers/convert_let_else_to_match.rs
index bf6b84ca7f..cfd176fcf2 100644
--- a/crates/ide-assists/src/handlers/convert_let_else_to_match.rs
+++ b/crates/ide-assists/src/handlers/convert_let_else_to_match.rs
@@ -1,4 +1,5 @@
 use syntax::ast::{edit::AstNodeEdit, AstNode, HasName, LetStmt, Pat};
+use syntax::T;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -95,7 +96,7 @@ fn binders_to_str(binders: &[(String, bool)], addmut: bool) -> String {
 //
 // ```
 // fn main() {
-//     let Ok(mut x) = f() else {$0 return };
+//     let Ok(mut x) = f() else$0 { return };
 // }
 // ```
 // ->
@@ -108,7 +109,9 @@ fn binders_to_str(binders: &[(String, bool)], addmut: bool) -> String {
 // }
 // ```
 pub(crate) fn convert_let_else_to_match(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let let_stmt: LetStmt = ctx.find_node_at_offset()?;
+    // should focus on else token to trigger
+    let else_token = ctx.find_token_syntax_at_offset(T![else])?;
+    let let_stmt = LetStmt::cast(else_token.parent()?.parent()?)?;
     let let_else_block = let_stmt.let_else()?.block_expr()?;
     let let_init = let_stmt.initializer()?;
     if let_stmt.ty().is_some() {
@@ -177,18 +180,30 @@ mod tests {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let 1: u32 = v.iter().sum() else {$0 return };
+    let 1: u32 = v.iter().sum() else$0 { return };
 }"#,
         );
     }
 
+    #[test]
+    fn convert_let_else_to_match_on_else() {
+        check_assist_not_applicable(
+            convert_let_else_to_match,
+            r#"
+fn main() {
+    let Ok(x) = f() else {$0 return };
+}
+            "#,
+        );
+    }
+
     #[test]
     fn convert_let_else_to_match_no_macropat() {
         check_assist_not_applicable(
             convert_let_else_to_match,
             r#"
 fn main() {
-    let m!() = g() else {$0 return };
+    let m!() = g() else$0 { return };
 }
             "#,
         );
@@ -200,7 +215,7 @@ fn main() {
             convert_let_else_to_match,
             r"
 fn main() {
-    let Ok(x) = f() else {$0 continue };
+    let Ok(x) = f() else$0 { continue };
 }",
             "let Ok(x) = f() else { continue };",
         );
@@ -212,7 +227,7 @@ fn main() {
             convert_let_else_to_match,
             r"
 fn main() {
-    let Ok(x) = f() else {$0 continue };
+    let Ok(x) = f() else$0 { continue };
 }",
             r"
 fn main() {
@@ -230,7 +245,7 @@ fn main() {
             convert_let_else_to_match,
             r"
 fn main() {
-    let Ok(mut x) = f() else {$0 continue };
+    let Ok(mut x) = f() el$0se { continue };
 }",
             r"
 fn main() {
@@ -248,7 +263,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let ControlFlow::Break((x, "tag", y, ..)) = f() else {$0 g(); return };
+    let ControlFlow::Break((x, "tag", y, ..)) = f() else$0 { g(); return };
 }"#,
             r#"
 fn main() {
@@ -266,7 +281,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let [one, 1001, other] = f() else {$0 break };
+    let [one, 1001, other] = f() else$0 { break };
 }"#,
             r#"
 fn main() {
@@ -284,7 +299,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let [Struct { inner: Some(it) }, 1001, other] = f() else {$0 break };
+    let [Struct { inner: Some(it) }, 1001, other] = f() else$0 { break };
 }"#,
             r#"
 fn main() {
@@ -302,7 +317,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let [Struct { inner }, 1001, other] = f() else {$0 break };
+    let [Struct { inner }, 1001, other] = f() else$0 { break };
 }"#,
             r#"
 fn main() {
@@ -320,7 +335,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let (8 | 9) = f() else {$0 panic!() };
+    let (8 | 9) = f() else$0 { panic!() };
 }"#,
             r#"
 fn main() {
@@ -338,7 +353,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let 1.. = f() else {$0 return };
+    let 1.. = f() e$0lse { return };
 }"#,
             r#"
 fn main() {
@@ -356,7 +371,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let Ok(&mut x) = f(&mut 0) else {$0 return };
+    let Ok(&mut x) = f(&mut 0) else$0 { return };
 }"#,
             r#"
 fn main() {
@@ -374,7 +389,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let Ok(ref mut x) = f() else {$0 return };
+    let Ok(ref mut x) = f() else$0 { return };
 }"#,
             r#"
 fn main() {
@@ -392,7 +407,7 @@ fn main() {
             convert_let_else_to_match,
             r#"
 fn main() {
-    let out @ Ok(ins) = f() else {$0 return };
+    let out @ Ok(ins) = f() else$0 { return };
 }"#,
             r#"
 fn main() {
@@ -411,7 +426,7 @@ fn main() {
             r#"
 fn main() {
     let v = vec![1, 2, 3];
-    let &[mut x, y, ..] = &v.iter().collect::<Vec<_>>()[..]$0 else { return };
+    let &[mut x, y, ..] = &v.iter().collect::<Vec<_>>()[..] else$0 { return };
 }"#,
             r#"
 fn main() {
diff --git a/crates/ide-assists/src/tests/generated.rs b/crates/ide-assists/src/tests/generated.rs
index 577387871a..008dd7eec1 100644
--- a/crates/ide-assists/src/tests/generated.rs
+++ b/crates/ide-assists/src/tests/generated.rs
@@ -370,7 +370,7 @@ fn doctest_convert_let_else_to_match() {
         "convert_let_else_to_match",
         r#####"
 fn main() {
-    let Ok(mut x) = f() else {$0 return };
+    let Ok(mut x) = f() else$0 { return };
 }
 "#####,
         r#####"