Adjust error node

Co-authored-by: Alexandre St-Louis Fortier <alexandre@unsplash.com>

src/compiler/checker.ts

@@ -45798,7 +45798,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             : exprType;
 
         const effectiveExpr = expr && getEffectiveCheckNode(expr); // The effective expression for diagnostics purposes.
-        const errorNode = inReturnStatement && !inConditionalExpression ? node : effectiveExpr;
+        const errorNode =
+          inConditionalExpression ? effectiveExpr :
+          inReturnStatement ? node :
+          isArrowFunction(node.parent) && node.parent.type !== undefined ? node.parent.type :
+          effectiveExpr;
 
         // If the return type is not narrowable, we simply check if the return expression type is assignable to the return type.
         if (!(unwrappedReturnType.flags & (TypeFlags.IndexedAccess | TypeFlags.Conditional)) || !couldContainTypeVariables(unwrappedReturnType)) {

tests/baselines/reference/arrowFunctionErrorSpan.errors.txt

@@ -20,7 +20,7 @@ arrowFunctionErrorSpan.ts(43,5): error TS2345: Argument of type '() => void' is
 arrowFunctionErrorSpan.ts(52,3): error TS2345: Argument of type '(_: any) => number' is not assignable to parameter of type '() => number'.
   Target signature provides too few arguments. Expected 1 or more, but got 0.
 arrowFunctionErrorSpan.ts(55,7): error TS2355: A function whose declared type is neither 'undefined', 'void', nor 'any' must return a value.
-arrowFunctionErrorSpan.ts(57,17): error TS2322: Type 'string' is not assignable to type 'number'.
+arrowFunctionErrorSpan.ts(57,7): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
 ==== arrowFunctionErrorSpan.ts (13 errors) ====
@@ -120,6 +120,6 @@ arrowFunctionErrorSpan.ts(57,17): error TS2322: Type 'string' is not assignable
 !!! error TS2355: A function whose declared type is neither 'undefined', 'void', nor 'any' must return a value.
 
     f((): number => '');
-                    ~~
+          ~~~~~~
 !!! error TS2322: Type 'string' is not assignable to type 'number'.
 

tests/baselines/reference/arrowFunctionReturnTypeErrorSpan.errors.txt

@@ -2,8 +2,8 @@ arrowFunctionReturnTypeErrorSpan.ts(2,7): error TS2451: Cannot redeclare block-s
 arrowFunctionReturnTypeErrorSpan.ts(3,3): error TS2322: Type 'string' is not assignable to type 'number'.
 arrowFunctionReturnTypeErrorSpan.ts(6,7): error TS2451: Cannot redeclare block-scoped variable 'a'.
 arrowFunctionReturnTypeErrorSpan.ts(7,10): error TS2304: Cannot find name 'missing'.
-arrowFunctionReturnTypeErrorSpan.ts(11,25): error TS2322: Type 'string' is not assignable to type 'number'.
-arrowFunctionReturnTypeErrorSpan.ts(14,28): error TS2322: Type 'string' is not assignable to type 'number'.
+arrowFunctionReturnTypeErrorSpan.ts(11,15): error TS2322: Type 'string' is not assignable to type 'number'.
+arrowFunctionReturnTypeErrorSpan.ts(14,15): error TS2322: Type 'string' is not assignable to type 'number'.
 arrowFunctionReturnTypeErrorSpan.ts(16,25): error TS2304: Cannot find name 'missing'.
 
 
@@ -27,12 +27,12 @@ arrowFunctionReturnTypeErrorSpan.ts(16,25): error TS2304: Cannot find name 'miss
 
     // expression body
     const b = (): number => "foo";
-                            ~~~~~
+                  ~~~~~~
 !!! error TS2322: Type 'string' is not assignable to type 'number'.
 
     type F<T> = T;
     const c = (): F<number> => "foo";
-                               ~~~~~
+                  ~~~~~~~~~
 !!! error TS2322: Type 'string' is not assignable to type 'number'.
 
     const d = (): number => missing;

tests/baselines/reference/conditionalTypes1.errors.txt

@@ -73,7 +73,7 @@ conditionalTypes1.ts(160,5): error TS2322: Type 'T' is not assignable to type 'Z
   Type 'string | number' is not assignable to type 'ZeroOf<T>'.
     Type 'string' is not assignable to type 'ZeroOf<T>'.
 conditionalTypes1.ts(263,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'z' must be of type 'T1', but here has type 'Foo<T & U>'.
-conditionalTypes1.ts(288,43): error TS2322: Type 'T95<U>' is not assignable to type 'T94<U>'.
+conditionalTypes1.ts(288,33): error TS2322: Type 'T95<U>' is not assignable to type 'T94<U>'.
   Type 'number | boolean' is not assignable to type 'T94<U>'.
     Type 'number' is not assignable to type 'T94<U>'.
       Type 'boolean' is not assignable to type 'true'.
@@ -465,7 +465,7 @@ conditionalTypes1.ts(288,43): error TS2322: Type 'T95<U>' is not assignable to t
     type T95<T> = T extends string ? boolean : number;
     const f44 = <U>(value: T94<U>): T95<U> => value;
     const f45 = <U>(value: T95<U>): T94<U> => value;  // Error
-                                              ~~~~~
+                                    ~~~~~~
 !!! error TS2322: Type 'T95<U>' is not assignable to type 'T94<U>'.
 !!! error TS2322:   Type 'number | boolean' is not assignable to type 'T94<U>'.
 !!! error TS2322:     Type 'number' is not assignable to type 'T94<U>'.

tests/baselines/reference/mappedTypeConstraints2.errors.txt

@@ -6,7 +6,7 @@ mappedTypeConstraints2.ts(16,11): error TS2322: Type 'Mapped3<K>[Uppercase<K>]'
 mappedTypeConstraints2.ts(42,7): error TS2322: Type 'Mapped6<K>[keyof Mapped6<K>]' is not assignable to type '`_${string}`'.
   Type 'Mapped6<K>[string] | Mapped6<K>[number] | Mapped6<K>[symbol]' is not assignable to type '`_${string}`'.
     Type 'Mapped6<K>[string]' is not assignable to type '`_${string}`'.
-mappedTypeConstraints2.ts(51,57): error TS2322: Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'.
+mappedTypeConstraints2.ts(51,52): error TS2322: Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'.
   'T' could be instantiated with an arbitrary type which could be unrelated to 'Foo<T>[`get${T}`]'.
 mappedTypeConstraints2.ts(82,9): error TS2322: Type 'ObjectWithUnderscoredKeys<K>[`_${K}`]' is not assignable to type 'true'.
   Type 'ObjectWithUnderscoredKeys<K>[`_${string}`]' is not assignable to type 'true'.
@@ -75,7 +75,7 @@ mappedTypeConstraints2.ts(82,9): error TS2322: Type 'ObjectWithUnderscoredKeys<K
     };
 
     const get = <T extends string>(t: T, foo: Foo<T>): T => foo[`get${t}`];  // Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'
-                                                            ~~~~~~~~~~~~~~
+                                                       ~
 !!! error TS2322: Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'.
 !!! error TS2322:   'T' could be instantiated with an arbitrary type which could be unrelated to 'Foo<T>[`get${T}`]'.
 

tests/baselines/reference/typeSatisfaction_errorLocations1.errors.txt

@@ -26,13 +26,13 @@ typeSatisfaction_errorLocations1.ts(36,9): error TS2345: Argument of type 'strin
 typeSatisfaction_errorLocations1.ts(39,3): error TS2322: Type 'string' is not assignable to type 'number'.
 typeSatisfaction_errorLocations1.ts(43,3): error TS2322: Type 'string' is not assignable to type 'number'.
 typeSatisfaction_errorLocations1.ts(43,16): error TS1360: Type 'string' does not satisfy the expected type 'number'.
-typeSatisfaction_errorLocations1.ts(46,22): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
+typeSatisfaction_errorLocations1.ts(46,6): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
 typeSatisfaction_errorLocations1.ts(47,24): error TS2322: Type 'number' is not assignable to type 'true'.
-typeSatisfaction_errorLocations1.ts(48,21): error TS2322: Type '{ a: number; }' is not assignable to type '{ a: true; }'.
+typeSatisfaction_errorLocations1.ts(48,6): error TS2322: Type '{ a: number; }' is not assignable to type '{ a: true; }'.
   Types of property 'a' are incompatible.
     Type 'number' is not assignable to type 'true'.
-typeSatisfaction_errorLocations1.ts(50,23): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
-typeSatisfaction_errorLocations1.ts(51,24): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
+typeSatisfaction_errorLocations1.ts(50,6): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
+typeSatisfaction_errorLocations1.ts(51,6): error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
 
 
 ==== typeSatisfaction_errorLocations1.ts (24 errors) ====
@@ -133,25 +133,25 @@ typeSatisfaction_errorLocations1.ts(51,24): error TS2741: Property 'a' is missin
     }
 
     ((): { a: true } => ({}) satisfies unknown)();
-                         ~~
+         ~~~~~~~~~~~
 !!! error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
 !!! related TS2728 typeSatisfaction_errorLocations1.ts:46:8: 'a' is declared here.
     ((): { a: true } => ({ a: 1 }) satisfies unknown)();
                            ~
 !!! error TS2322: Type 'number' is not assignable to type 'true'.
 !!! related TS6500 typeSatisfaction_errorLocations1.ts:47:8: The expected type comes from property 'a' which is declared here on type '{ a: true; }'
     ((): { a: true } => obj1 satisfies unknown)();
-                        ~~~~
+         ~~~~~~~~~~~
 !!! error TS2322: Type '{ a: number; }' is not assignable to type '{ a: true; }'.
 !!! error TS2322:   Types of property 'a' are incompatible.
 !!! error TS2322:     Type 'number' is not assignable to type 'true'.
 
     ((): { a: true } => (({}) satisfies unknown) satisfies unknown)();
-                          ~~
+         ~~~~~~~~~~~
 !!! error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
 !!! related TS2728 typeSatisfaction_errorLocations1.ts:50:8: 'a' is declared here.
     ((): { a: true } => ((({}) satisfies unknown)) satisfies unknown)();
-                           ~~
+         ~~~~~~~~~~~
 !!! error TS2741: Property 'a' is missing in type '{}' but required in type '{ a: true; }'.
 !!! related TS2728 typeSatisfaction_errorLocations1.ts:51:8: 'a' is declared here.