Merge #11481

[rust.git] / crates / ide_assists / src / handlers / move_guard.rs

diff --git a/crates/ide_assists/src/handlers/move_guard.rs b/crates/ide_assists/src/handlers/move_guard.rs
index 4dcb6d91f97a9db41a8e8ba39d804276b1cff56a..5c05cb921d9dcd66eae026c061f2e18ad686b89b 100644 (file)
--- a/crates/ide_assists/src/handlers/move_guard.rs
+++ b/crates/ide_assists/src/handlers/move_guard.rs
@@ -1,7 +1,5 @@
 use syntax::{
-    ast::{
-        edit::AstNodeEdit, make, AstNode, BlockExpr, Condition, ElseBranch, Expr, IfExpr, MatchArm,
-    },
+    ast::{edit::AstNodeEdit, make, AstNode, BlockExpr, ElseBranch, Expr, IfExpr, MatchArm, Pat},
     SyntaxKind::WHITESPACE,
 };
 
@@ -43,18 +41,11 @@ pub(crate) fn move_guard_to_arm_body(acc: &mut Assists, ctx: &AssistContext) ->
     }
     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(
@@ -175,23 +166,30 @@ pub(crate) fn move_arm_cond_to_match_guard(acc: &mut Assists, ctx: &AssistContex
                     }
                 }
             } 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)),
+                }
             }
         },
     )
 }
 
-// Parses an if-else-if chain to get the conditons and the then branches until we encounter an else
-// branch, an if-let branch or the end.
-fn parse_if_chain(if_expr: IfExpr) -> Option<(Vec<(Condition, BlockExpr)>, Option<BlockExpr>)> {
+// 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()?;
-        // Not support moving if let to arm guard
-        if cond.is_pattern_cond() {
-            return None;
-        }
         conds_blocks.push((cond, curr_if.then_branch()?));
         match curr_if.else_branch() {
             Some(ElseBranch::IfExpr(e)) => {
@@ -268,6 +266,31 @@ fn main() {
         );
     }
 
+    #[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(
@@ -318,6 +341,7 @@ fn main() {
 
     #[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#"
@@ -343,6 +367,62 @@ fn main() {
         );
     }
 
+    #[test]
+    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(
@@ -371,13 +451,21 @@ fn main() {
     }
 
     #[test]
-    fn move_arm_cond_to_match_guard_if_let_not_works() {
-        check_assist_not_applicable(
+    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
     }
 }
@@ -829,7 +917,7 @@ fn main() {
 
     #[test]
     fn move_arm_cond_to_match_guard_elseif_iflet() {
-        check_assist_not_applicable(
+        check_assist(
             move_arm_cond_to_match_guard,
             r#"
 fn main() {
@@ -846,9 +934,21 @@ fn main() {
             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]
@@ -881,6 +981,7 @@ fn main() {
             42;
             3
         }
+        x => {}
     }
 }
 "#,