bool_to_int_with_if inverse case patch

clippy_lints/src/bool_to_int_with_if.rs

@@ -55,15 +55,28 @@ fn check_if_else<'tcx>(ctx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx
     if let ExprKind::If(check, then, Some(else_)) = expr.kind
         && let Some(then_lit) = int_literal(then)
         && let Some(else_lit) = int_literal(else_)
-        && check_int_literal_equals_val(then_lit, 1)
-        && check_int_literal_equals_val(else_lit, 0)
     {
+        let inverted = if
+            check_int_literal_equals_val(then_lit, 1)
+            && check_int_literal_equals_val(else_lit, 0) {
+            false
+        } else if
+            check_int_literal_equals_val(then_lit, 0)
+            && check_int_literal_equals_val(else_lit, 1) {
+            true
+        } else {
+            // Expression isn't boolean, exit
+            return;
+        };
         let mut applicability = Applicability::MachineApplicable;
         let snippet = snippet_block_with_applicability(ctx, check.span, "..", None, &mut applicability);
+
+        let invert = if inverted { "!" } else { "" };
+        let need_parens = should_have_parentheses(check);
+
         let snippet_with_braces = {
-            let need_parens = should_have_parentheses(check);
             let (left_paren, right_paren) = if need_parens {("(", ")")} else {("", "")};
-            format!("{left_paren}{snippet}{right_paren}")
+            format!("{invert}{left_paren}{snippet}{right_paren}")
         };
 
         let ty = ctx.typeck_results().expr_ty(then_lit); // then and else must be of same type
@@ -71,11 +84,14 @@ fn check_if_else<'tcx>(ctx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx
         let suggestion = {
             let wrap_in_curly = is_else_clause(ctx.tcx, expr);
             let (left_curly, right_curly) = if wrap_in_curly {("{", "}")} else {("", "")};
+            let (left_paren, right_paren) = if inverted && need_parens {("(", ")")} else {("", "")};
             format!(
-                "{left_curly}{ty}::from({snippet}){right_curly}"
+                "{left_curly}{ty}::from({invert}{left_paren}{snippet}{right_paren}){right_curly}"
             )
         }; // when used in else clause if statement should be wrapped in curly braces
 
+        let (inverted_left_paren, inverted_right_paren) = if inverted {("(", ")")} else {("", "")};
+
         span_lint_and_then(ctx,
             BOOL_TO_INT_WITH_IF,
             expr.span,
@@ -87,7 +103,7 @@ fn check_if_else<'tcx>(ctx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx
                 suggestion,
                 applicability,
             );
-            diag.note(format!("`{snippet_with_braces} as {ty}` or `{snippet_with_braces}.into()` can also be valid options"));
+            diag.note(format!("`{snippet_with_braces} as {ty}` or `{inverted_left_paren}{snippet_with_braces}{inverted_right_paren}.into()` can also be valid options"));
         });
     };
 }

tests/ui/bool_to_int_with_if.fixed

@@ -14,6 +14,7 @@ fn main() {
     // precedence
     i32::from(a);
     i32::from(!a);
+    i32::from(!a);
     i32::from(a || b);
     i32::from(cond(a, b));
     i32::from(x + y < 4);
@@ -23,6 +24,11 @@ fn main() {
         123
     } else {i32::from(b)};
 
+    // if else if inverted
+    if a {
+        123
+    } else {i32::from(!b)};
+
     // Shouldn't lint
 
     if a {

tests/ui/bool_to_int_with_if.rs

@@ -17,6 +17,11 @@ fn main() {
     } else {
         0
     };
+    if a {
+        0
+    } else {
+        1
+    };
     if !a {
         1
     } else {
@@ -47,6 +52,15 @@ fn main() {
         0
     };
 
+    // if else if inverted
+    if a {
+        123
+    } else if b {
+        0
+    } else {
+        1
+    };
+
     // Shouldn't lint
 
     if a {

tests/ui/bool_to_int_with_if.stderr

@@ -14,6 +14,18 @@ LL | |     };
 error: boolean to int conversion using if
   --> $DIR/bool_to_int_with_if.rs:20:5
    |
+LL | /     if a {
+LL | |         0
+LL | |     } else {
+LL | |         1
+LL | |     };
+   | |_____^ help: replace with from: `i32::from(!a)`
+   |
+   = note: `!a as i32` or `(!a).into()` can also be valid options
+
+error: boolean to int conversion using if
+  --> $DIR/bool_to_int_with_if.rs:25:5
+   |
 LL | /     if !a {
 LL | |         1
 LL | |     } else {
@@ -24,7 +36,7 @@ LL | |     };
    = note: `!a as i32` or `!a.into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:25:5
+  --> $DIR/bool_to_int_with_if.rs:30:5
    |
 LL | /     if a || b {
 LL | |         1
@@ -36,7 +48,7 @@ LL | |     };
    = note: `(a || b) as i32` or `(a || b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:30:5
+  --> $DIR/bool_to_int_with_if.rs:35:5
    |
 LL | /     if cond(a, b) {
 LL | |         1
@@ -48,7 +60,7 @@ LL | |     };
    = note: `cond(a, b) as i32` or `cond(a, b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:35:5
+  --> $DIR/bool_to_int_with_if.rs:40:5
    |
 LL | /     if x + y < 4 {
 LL | |         1
@@ -60,7 +72,7 @@ LL | |     };
    = note: `(x + y < 4) as i32` or `(x + y < 4).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:44:12
+  --> $DIR/bool_to_int_with_if.rs:49:12
    |
 LL |       } else if b {
    |  ____________^
@@ -73,12 +85,25 @@ LL | |     };
    = note: `b as i32` or `b.into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:102:5
+  --> $DIR/bool_to_int_with_if.rs:58:12
+   |
+LL |       } else if b {
+   |  ____________^
+LL | |         0
+LL | |     } else {
+LL | |         1
+LL | |     };
+   | |_____^ help: replace with from: `{i32::from(!b)}`
+   |
+   = note: `!b as i32` or `(!b).into()` can also be valid options
+
+error: boolean to int conversion using if
+  --> $DIR/bool_to_int_with_if.rs:116:5
    |
 LL |     if a { 1 } else { 0 }
    |     ^^^^^^^^^^^^^^^^^^^^^ help: replace with from: `u8::from(a)`
    |
    = note: `a as u8` or `a.into()` can also be valid options
 
-error: aborting due to 7 previous errors
+error: aborting due to 9 previous errors