Merge pull request #18797 from profetia/issue10583

Fix replace-if-let-with-match generates non-exhausive match

2 files changed, 758 insertions, 34 deletions

diff --git a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/replace_if_let_with_match.rs b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/replace_if_let_with_match.rs
index 56dd6cf29ae..4313cc1ac9d 100644
--- a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/replace_if_let_with_match.rs
+++ b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/replace_if_let_with_match.rs
@@ -17,7 +17,7 @@ use syntax::{
 };
 
 use crate::{
-    utils::{does_nested_pattern, does_pat_match_variant, unwrap_trivial_block},
+    utils::{does_pat_match_variant, does_pat_variant_nested_or_literal, unwrap_trivial_block},
     AssistContext, AssistId, AssistKind, Assists,
 };
 
@@ -163,7 +163,7 @@ fn make_else_arm(
                 Some(it) => {
                     if does_pat_match_variant(pat, &it.sad_pattern()) {
                         it.happy_pattern_wildcard()
-                    } else if does_nested_pattern(pat) {
+                    } else if does_pat_variant_nested_or_literal(ctx, pat) {
                         make::wildcard_pat().into()
                     } else {
                         it.sad_pattern()
@@ -702,11 +702,11 @@ fn main() {
     }
 
     #[test]
-    fn nested_type() {
+    fn test_if_let_with_match_nested_tuple_struct() {
         check_assist(
             replace_if_let_with_match,
             r#"
-//- minicore: result
+//- minicore: result, option
 fn foo(x: Result<i32, ()>) {
     let bar: Result<_, ()> = Ok(Some(1));
     $0if let Ok(Some(_)) = bar {
@@ -726,6 +726,700 @@ fn foo(x: Result<i32, ()>) {
 }
 "#,
         );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+struct MyStruct(i32, i32);
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct(1, 2));
+    $0if let Ok(MyStruct(a, b)) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+struct MyStruct(i32, i32);
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct(1, 2));
+    match bar {
+        Ok(MyStruct(a, b)) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_slice() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<&[i32], ()>) {
+    let foo: Result<&[_], ()> = Ok(&[0, 1, 2]);
+    $0if let Ok([]) = foo {
+        ()
+    } else {
+        ()
+    }
+}
+        "#,
+            r#"
+fn foo(x: Result<&[i32], ()>) {
+    let foo: Result<&[_], ()> = Ok(&[0, 1, 2]);
+    match foo {
+        Ok([]) => (),
+        _ => (),
+    }
+}
+        "#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<[&'static str; 2], ()>) {
+    let foobar: Result<_, ()> = Ok(["foo", "bar"]);
+    $0if let Ok([_, "bar"]) = foobar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<[&'static str; 2], ()>) {
+    let foobar: Result<_, ()> = Ok(["foo", "bar"]);
+    match foobar {
+        Ok([_, "bar"]) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<[&'static str; 2], ()>) {
+    let foobar: Result<_, ()> = Ok(["foo", "bar"]);
+    $0if let Ok([..]) = foobar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<[&'static str; 2], ()>) {
+    let foobar: Result<_, ()> = Ok(["foo", "bar"]);
+    match foobar {
+        Ok([..]) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<&[&'static str], ()>) {
+    let foobar: Result<&[&'static str], ()> = Ok(&["foo", "bar"]);
+    $0if let Ok([a, ..]) = foobar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<&[&'static str], ()>) {
+    let foobar: Result<&[&'static str], ()> = Ok(&["foo", "bar"]);
+    match foobar {
+        Ok([a, ..]) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<&[&'static str], ()>) {
+    let foobar: Result<&[&'static str], ()> = Ok(&["foo", "bar"]);
+    $0if let Ok([a, .., b, c]) = foobar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<&[&'static str], ()>) {
+    let foobar: Result<&[&'static str], ()> = Ok(&["foo", "bar"]);
+    match foobar {
+        Ok([a, .., b, c]) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<Option<[&'static str; 2]>, ()>) {
+    let foobar: Result<_, ()> = Ok(Some(["foo", "bar"]));
+    $0if let Ok(Some([_, "bar"])) = foobar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<Option<[&'static str; 2]>, ()>) {
+    let foobar: Result<_, ()> = Ok(Some(["foo", "bar"]));
+    match foobar {
+        Ok(Some([_, "bar"])) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_literal() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<&'static str, ()>) {
+    let bar: Result<&_, ()> = Ok("bar");
+    $0if let Ok("foo") = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<&'static str, ()>) {
+    let bar: Result<&_, ()> = Ok("bar");
+    match bar {
+        Ok("foo") => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_tuple() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32, i32), ()>) {
+    let bar: Result<(i32, i32, i32), ()> = Ok((1, 2, 3));
+    $0if let Ok((1, second, third)) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32, i32), ()>) {
+    let bar: Result<(i32, i32, i32), ()> = Ok((1, 2, 3));
+    match bar {
+        Ok((1, second, third)) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32, i32), ()>) {
+    let bar: Result<(i32, i32, i32), ()> = Ok((1, 2, 3));
+    $0if let Ok((first, second, third)) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32, i32), ()>) {
+    let bar: Result<(i32, i32, i32), ()> = Ok((1, 2, 3));
+    match bar {
+        Ok((first, second, third)) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_or() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(1 | 2) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(1 | 2) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 2));
+    $0if let Ok((b, a) | (a, b)) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 2));
+    match bar {
+        Ok((b, a) | (a, b)) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 2));
+    $0if let Ok((1, a) | (a, 2)) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 2));
+    match bar {
+        Ok((1, a) | (a, 2)) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_range() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(1..2) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(1..2) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_paren() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 1));
+    $0if let Ok(((1, 2))) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 1));
+    match bar {
+        Ok(((1, 2))) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 1));
+    $0if let Ok(((a, b))) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<(i32, i32), ()>) {
+    let bar: Result<(i32, i32), ()> = Ok((1, 1));
+    match bar {
+        Ok(((a, b))) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_macro() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    macro_rules! is_42 {
+        () => {
+            42
+        };
+    }
+
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(is_42!()) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    macro_rules! is_42 {
+        () => {
+            42
+        };
+    }
+
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(is_42!()) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_path() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+enum MyEnum {
+    Foo,
+    Bar,
+}
+
+fn foo(x: Result<MyEnum, ()>) {
+    let bar: Result<MyEnum, ()> = Ok(MyEnum::Foo);
+    $0if let Ok(MyEnum::Foo) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+enum MyEnum {
+    Foo,
+    Bar,
+}
+
+fn foo(x: Result<MyEnum, ()>) {
+    let bar: Result<MyEnum, ()> = Ok(MyEnum::Foo);
+    match bar {
+        Ok(MyEnum::Foo) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_record() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    $0if let Ok(MyStruct { foo, bar }) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    match bar {
+        Ok(MyStruct { foo, bar }) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    $0if let Ok(MyStruct { foo, bar: 12 }) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    match bar {
+        Ok(MyStruct { foo, bar: 12 }) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    $0if let Ok(MyStruct { foo, .. }) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+struct MyStruct {
+    foo: i32,
+    bar: i32,
+}
+
+fn foo(x: Result<MyStruct, ()>) {
+    let bar: Result<MyStruct, ()> = Ok(MyStruct { foo: 1, bar: 2 });
+    match bar {
+        Ok(MyStruct { foo, .. }) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+enum MyEnum {
+    Foo(i32, i32),
+    Bar { a: i32, b: i32 },
+}
+
+fn foo(x: Result<MyEnum, ()>) {
+    let bar: Result<MyEnum, ()> = Ok(MyEnum::Foo(1, 2));
+    $0if let Ok(MyEnum::Bar { a, b }) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+enum MyEnum {
+    Foo(i32, i32),
+    Bar { a: i32, b: i32 },
+}
+
+fn foo(x: Result<MyEnum, ()>) {
+    let bar: Result<MyEnum, ()> = Ok(MyEnum::Foo(1, 2));
+    match bar {
+        Ok(MyEnum::Bar { a, b }) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_if_let_with_match_nested_ident() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(a @ 1..2) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(a @ 1..2) => (),
+        _ => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(a) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(a) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
+
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+//- minicore: result
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    $0if let Ok(a @ b @ c @ d) = bar {
+        ()
+    } else {
+        ()
+    }
+}
+"#,
+            r#"
+fn foo(x: Result<i32, ()>) {
+    let bar: Result<i32, ()> = Ok(1);
+    match bar {
+        Ok(a @ b @ c @ d) => (),
+        Err(_) => (),
+    }
+}
+"#,
+        );
     }
 
     #[test]
diff --git a/src/tools/rust-analyzer/crates/ide-assists/src/utils.rs b/src/tools/rust-analyzer/crates/ide-assists/src/utils.rs
index 3c26b043597..ce0bd46e6f3 100644
--- a/src/tools/rust-analyzer/crates/ide-assists/src/utils.rs
+++ b/src/tools/rust-analyzer/crates/ide-assists/src/utils.rs
@@ -316,43 +316,73 @@ pub(crate) fn does_pat_match_variant(pat: &ast::Pat, var: &ast::Pat) -> bool {
     pat_head == var_head
 }
 
-pub(crate) fn does_nested_pattern(pat: &ast::Pat) -> bool {
-    let depth = calc_depth(pat, 0);
+pub(crate) fn does_pat_variant_nested_or_literal(ctx: &AssistContext<'_>, pat: &ast::Pat) -> bool {
+    check_pat_variant_nested_or_literal_with_depth(ctx, pat, 0)
+}
+
+fn check_pat_variant_from_enum(ctx: &AssistContext<'_>, pat: &ast::Pat) -> bool {
+    ctx.sema.type_of_pat(pat).map_or(true, |ty: hir::TypeInfo| {
+        ty.adjusted().as_adt().map_or(false, |adt| matches!(adt, hir::Adt::Enum(_)))
+    })
+}
 
-    if 1 < depth {
+fn check_pat_variant_nested_or_literal_with_depth(
+    ctx: &AssistContext<'_>,
+    pat: &ast::Pat,
+    depth_after_refutable: usize,
+) -> bool {
+    if depth_after_refutable > 1 {
         return true;
     }
-    false
-}
 
-fn calc_depth(pat: &ast::Pat, depth: usize) -> usize {
     match pat {
-        ast::Pat::IdentPat(_)
-        | ast::Pat::BoxPat(_)
-        | ast::Pat::RestPat(_)
-        | ast::Pat::LiteralPat(_)
+        ast::Pat::RestPat(_) | ast::Pat::WildcardPat(_) | ast::Pat::RefPat(_) => false,
+
+        ast::Pat::LiteralPat(_)
+        | ast::Pat::RangePat(_)
         | ast::Pat::MacroPat(_)
-        | ast::Pat::OrPat(_)
-        | ast::Pat::ParenPat(_)
         | ast::Pat::PathPat(_)
-        | ast::Pat::WildcardPat(_)
-        | ast::Pat::RangePat(_)
-        | ast::Pat::RecordPat(_)
-        | ast::Pat::RefPat(_)
-        | ast::Pat::SlicePat(_)
-        | ast::Pat::TuplePat(_)
-        | ast::Pat::ConstBlockPat(_) => depth,
-
-        // FIXME: Other patterns may also be nested. Currently it simply supports only `TupleStructPat`
-        ast::Pat::TupleStructPat(pat) => {
-            let mut max_depth = depth;
-            for p in pat.fields() {
-                let d = calc_depth(&p, depth + 1);
-                if d > max_depth {
-                    max_depth = d
-                }
-            }
-            max_depth
+        | ast::Pat::BoxPat(_)
+        | ast::Pat::ConstBlockPat(_) => true,
+
+        ast::Pat::IdentPat(ident_pat) => ident_pat.pat().map_or(false, |pat| {
+            check_pat_variant_nested_or_literal_with_depth(ctx, &pat, depth_after_refutable)
+        }),
+        ast::Pat::ParenPat(paren_pat) => paren_pat.pat().map_or(true, |pat| {
+            check_pat_variant_nested_or_literal_with_depth(ctx, &pat, depth_after_refutable)
+        }),
+        ast::Pat::TuplePat(tuple_pat) => tuple_pat.fields().any(|pat| {
+            check_pat_variant_nested_or_literal_with_depth(ctx, &pat, depth_after_refutable)
+        }),
+        ast::Pat::RecordPat(record_pat) => {
+            let adjusted_next_depth =
+                depth_after_refutable + if check_pat_variant_from_enum(ctx, pat) { 1 } else { 0 };
+            record_pat.record_pat_field_list().map_or(true, |pat| {
+                pat.fields().any(|pat| {
+                    pat.pat().map_or(true, |pat| {
+                        check_pat_variant_nested_or_literal_with_depth(
+                            ctx,
+                            &pat,
+                            adjusted_next_depth,
+                        )
+                    })
+                })
+            })
+        }
+        ast::Pat::OrPat(or_pat) => or_pat.pats().any(|pat| {
+            check_pat_variant_nested_or_literal_with_depth(ctx, &pat, depth_after_refutable)
+        }),
+        ast::Pat::TupleStructPat(tuple_struct_pat) => {
+            let adjusted_next_depth =
+                depth_after_refutable + if check_pat_variant_from_enum(ctx, pat) { 1 } else { 0 };
+            tuple_struct_pat.fields().any(|pat| {
+                check_pat_variant_nested_or_literal_with_depth(ctx, &pat, adjusted_next_depth)
+            })
+        }
+        ast::Pat::SlicePat(slice_pat) => {
+            let mut pats = slice_pat.pats();
+            pats.next() // Edge case for `[..]`
+                .map_or(true, |pat| !matches!(pat, ast::Pat::RestPat(_)) || pats.next().is_some())
         }
     }
 }