highlight double negations as safe to remove

Author: giacomocavalieri

CHANGELOG.md

@@ -107,3 +107,8 @@
 - Fixed a bug where `echo` could crash on JavaScript if the module contains
   record variants with the same name as some built-in JavaScript objects.
   ([Louis Pilfold](https://github.com/lpil))
+
+- Fixed a bug where the compiler would highlight an entire double negation
+  expression as safe to remove, instead of just highlighting the double
+  negation.
+  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

compiler-core/src/type_/expression.rs

@@ -884,9 +884,18 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
                 .error(convert_unify_error(error, value.location()))
         }
 
-        if let TypedExpr::NegateBool { .. } = value {
+        if let TypedExpr::NegateBool {
+            location: inner_location,
+            ..
+        } = value
+        {
             self.problems
-                .warning(Warning::UnnecessaryDoubleBoolNegation { location });
+                .warning(Warning::UnnecessaryDoubleBoolNegation {
+                    location: SrcSpan {
+                        start: location.start,
+                        end: inner_location.start + 1,
+                    },
+                });
         }
 
         TypedExpr::NegateBool {
@@ -903,16 +912,34 @@ impl<'a, 'b> ExprTyper<'a, 'b> {
                 .error(convert_unify_error(error, value.location()));
         }
 
-        if let TypedExpr::Int { value: ref v, .. } = value
+        if let TypedExpr::Int {
+            value: ref v,
+            location: ref inner_location,
+            ..
+        } = value
             && v.starts_with('-')
         {
             self.problems
-                .warning(Warning::UnnecessaryDoubleIntNegation { location });
+                .warning(Warning::UnnecessaryDoubleIntNegation {
+                    location: SrcSpan {
+                        start: location.start,
+                        end: inner_location.start + 1,
+                    },
+                });
         }
 
-        if let TypedExpr::NegateInt { .. } = value {
+        if let TypedExpr::NegateInt {
+            location: inner_location,
+            ..
+        } = value
+        {
             self.problems
-                .warning(Warning::UnnecessaryDoubleIntNegation { location });
+                .warning(Warning::UnnecessaryDoubleIntNegation {
+                    location: SrcSpan {
+                        start: location.start,
+                        end: inner_location.start + 1,
+                    },
+                });
         }
 
         TypedExpr::NegateInt {

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__warnings__double_unary_bool_literal.snap

@@ -10,6 +10,4 @@ warning: Unnecessary double negation (!!) on bool
   ┌─ /src/warning/wrn.gleam:1:25
   │
 1 │ pub fn main() { let _ = !!True }
-  │                         ^^^^^^
-
-Hint: You can safely remove this.
+  │                         ^^ You can safely remove this.

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__warnings__double_unary_bool_variable.snap

@@ -15,6 +15,4 @@ warning: Unnecessary double negation (!!) on bool
   ┌─ /src/warning/wrn.gleam:4:21
   │
 4 │             let _ = !!x
-  │                     ^^^
-
-Hint: You can safely remove this.
+  │                     ^^ You can safely remove this.

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__warnings__double_unary_integer_literal.snap

@@ -10,6 +10,4 @@ warning: Unnecessary double negation (--) on integer
   ┌─ /src/warning/wrn.gleam:1:25
   │
 1 │ pub fn main() { let _ = --7 }
-  │                         ^^^
-
-Hint: You can safely remove this.
+  │                         ^^ You can safely remove this.

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__warnings__double_unary_integer_variable.snap

@@ -15,6 +15,4 @@ warning: Unnecessary double negation (--) on integer
   ┌─ /src/warning/wrn.gleam:4:21
   │
 4 │             let _ = --x
-  │                     ^^^
-
-Hint: You can safely remove this.
+  │                     ^^ You can safely remove this.

compiler-core/src/warning.rs

@@ -679,13 +679,13 @@ Hint: You can safely remove it.
                 type_::Warning::UnnecessaryDoubleIntNegation { location } => Diagnostic {
                     title: "Unnecessary double negation (--) on integer".into(),
                     text: "".into(),
-                    hint: Some("You can safely remove this.".into()),
+                    hint: None,
                     level: diagnostic::Level::Warning,
                     location: Some(Location {
                         src: src.clone(),
                         path: path.to_path_buf(),
                         label: diagnostic::Label {
-                            text: None,
+                            text: Some("You can safely remove this.".into()),
                             span: *location,
                         },
                         extra_labels: Vec::new(),
@@ -694,13 +694,13 @@ Hint: You can safely remove it.
                 type_::Warning::UnnecessaryDoubleBoolNegation { location } => Diagnostic {
                     title: "Unnecessary double negation (!!) on bool".into(),
                     text: "".into(),
-                    hint: Some("You can safely remove this.".into()),
+                    hint: None,
                     level: diagnostic::Level::Warning,
                     location: Some(Location {
                         src: src.clone(),
                         path: path.to_path_buf(),
                         label: diagnostic::Label {
-                            text: None,
+                            text: Some("You can safely remove this.".into()),
                             span: *location,
                         },
                         extra_labels: Vec::new(),