Fix assignment of intersections to objects with optional properties

src/compiler/checker.ts

@@ -15378,7 +15378,9 @@ namespace ts {
                         //
                         //    - For a primitive type or type parameter (such as 'number = A & B') there is no point in
                         //          breaking the intersection apart.
-                        result = someTypeRelatedToType(<IntersectionType>source, target, /*reportErrors*/ false, IntersectionState.Source);
+                        if (!isNonGenericObjectType(target) || !every((<IntersectionType>source).types, t => isNonGenericObjectType(t) && !(getObjectFlags(t) & ObjectFlags.NonInferrableType))) {
+                            result = someTypeRelatedToType(<IntersectionType>source, target, /*reportErrors*/ false, IntersectionState.Source);
+                        }
                     }
                     if (!result && (source.flags & TypeFlags.StructuredOrInstantiable || target.flags & TypeFlags.StructuredOrInstantiable)) {
                         if (result = recursiveTypeRelatedTo(source, target, reportErrors, intersectionState)) {

tests/baselines/reference/intersectionsAndOptionalProperties.errors.txt

@@ -0,0 +1,49 @@
+tests/cases/compiler/intersectionsAndOptionalProperties.ts(5,1): error TS2322: Type '{ a: null; b: string; }' is not assignable to type '{ a?: number | undefined; b: string; }'.
+  Types of property 'a' are incompatible.
+    Type 'null' is not assignable to type 'number | undefined'.
+tests/cases/compiler/intersectionsAndOptionalProperties.ts(6,1): error TS2322: Type '{ a: null; } & { b: string; }' is not assignable to type '{ a?: number | undefined; b: string; }'.
+  Types of property 'a' are incompatible.
+    Type 'null' is not assignable to type 'number | undefined'.
+tests/cases/compiler/intersectionsAndOptionalProperties.ts(19,5): error TS2322: Type 'From' is not assignable to type 'To'.
+  Types of property 'field' are incompatible.
+    Type 'null' is not assignable to type 'number | undefined'.
+tests/cases/compiler/intersectionsAndOptionalProperties.ts(20,5): error TS2322: Type 'null' is not assignable to type 'number | undefined'.
+
+
+==== tests/cases/compiler/intersectionsAndOptionalProperties.ts (4 errors) ====
+    declare let x: { a?: number, b: string };
+    declare let y: { a: null, b: string };
+    declare let z: { a: null } & { b: string };
+
+    x = y;  // Error
+    ~
+!!! error TS2322: Type '{ a: null; b: string; }' is not assignable to type '{ a?: number | undefined; b: string; }'.
+!!! error TS2322:   Types of property 'a' are incompatible.
+!!! error TS2322:     Type 'null' is not assignable to type 'number | undefined'.
+    x = z;  // Error
+    ~
+!!! error TS2322: Type '{ a: null; } & { b: string; }' is not assignable to type '{ a?: number | undefined; b: string; }'.
+!!! error TS2322:   Types of property 'a' are incompatible.
+!!! error TS2322:     Type 'null' is not assignable to type 'number | undefined'.
+
+    // Repro from #36604
+
+    interface To {
+        field?: number;
+        anotherField: string;
+    }
+
+    type From =  { field: null } & Omit<To, 'field'>;
+
+    function foo(v: From) {
+        let x: To;
+        x = v;  // Error
+        ~
+!!! error TS2322: Type 'From' is not assignable to type 'To'.
+!!! error TS2322:   Types of property 'field' are incompatible.
+!!! error TS2322:     Type 'null' is not assignable to type 'number | undefined'.
+        x.field = v.field; // Error
+        ~~~~~~~
+!!! error TS2322: Type 'null' is not assignable to type 'number | undefined'.
+    }
+

tests/baselines/reference/intersectionsAndOptionalProperties.js

@@ -0,0 +1,33 @@
+//// [intersectionsAndOptionalProperties.ts]
+declare let x: { a?: number, b: string };
+declare let y: { a: null, b: string };
+declare let z: { a: null } & { b: string };
+
+x = y;  // Error
+x = z;  // Error
+
+// Repro from #36604
+
+interface To {
+    field?: number;
+    anotherField: string;
+}
+
+type From =  { field: null } & Omit<To, 'field'>;
+
+function foo(v: From) {
+    let x: To;
+    x = v;  // Error
+    x.field = v.field; // Error
+}
+
+
+//// [intersectionsAndOptionalProperties.js]
+"use strict";
+x = y; // Error
+x = z; // Error
+function foo(v) {
+    var x;
+    x = v; // Error
+    x.field = v.field; // Error
+}

tests/baselines/reference/intersectionsAndOptionalProperties.symbols

@@ -0,0 +1,64 @@
+=== tests/cases/compiler/intersectionsAndOptionalProperties.ts ===
+declare let x: { a?: number, b: string };
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 0, 11))
+>a : Symbol(a, Decl(intersectionsAndOptionalProperties.ts, 0, 16))
+>b : Symbol(b, Decl(intersectionsAndOptionalProperties.ts, 0, 28))
+
+declare let y: { a: null, b: string };
+>y : Symbol(y, Decl(intersectionsAndOptionalProperties.ts, 1, 11))
+>a : Symbol(a, Decl(intersectionsAndOptionalProperties.ts, 1, 16))
+>b : Symbol(b, Decl(intersectionsAndOptionalProperties.ts, 1, 25))
+
+declare let z: { a: null } & { b: string };
+>z : Symbol(z, Decl(intersectionsAndOptionalProperties.ts, 2, 11))
+>a : Symbol(a, Decl(intersectionsAndOptionalProperties.ts, 2, 16))
+>b : Symbol(b, Decl(intersectionsAndOptionalProperties.ts, 2, 30))
+
+x = y;  // Error
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 0, 11))
+>y : Symbol(y, Decl(intersectionsAndOptionalProperties.ts, 1, 11))
+
+x = z;  // Error
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 0, 11))
+>z : Symbol(z, Decl(intersectionsAndOptionalProperties.ts, 2, 11))
+
+// Repro from #36604
+
+interface To {
+>To : Symbol(To, Decl(intersectionsAndOptionalProperties.ts, 5, 6))
+
+    field?: number;
+>field : Symbol(To.field, Decl(intersectionsAndOptionalProperties.ts, 9, 14))
+
+    anotherField: string;
+>anotherField : Symbol(To.anotherField, Decl(intersectionsAndOptionalProperties.ts, 10, 19))
+}
+
+type From =  { field: null } & Omit<To, 'field'>;
+>From : Symbol(From, Decl(intersectionsAndOptionalProperties.ts, 12, 1))
+>field : Symbol(field, Decl(intersectionsAndOptionalProperties.ts, 14, 14))
+>Omit : Symbol(Omit, Decl(lib.es5.d.ts, --, --))
+>To : Symbol(To, Decl(intersectionsAndOptionalProperties.ts, 5, 6))
+
+function foo(v: From) {
+>foo : Symbol(foo, Decl(intersectionsAndOptionalProperties.ts, 14, 49))
+>v : Symbol(v, Decl(intersectionsAndOptionalProperties.ts, 16, 13))
+>From : Symbol(From, Decl(intersectionsAndOptionalProperties.ts, 12, 1))
+
+    let x: To;
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 17, 7))
+>To : Symbol(To, Decl(intersectionsAndOptionalProperties.ts, 5, 6))
+
+    x = v;  // Error
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 17, 7))
+>v : Symbol(v, Decl(intersectionsAndOptionalProperties.ts, 16, 13))
+
+    x.field = v.field; // Error
+>x.field : Symbol(To.field, Decl(intersectionsAndOptionalProperties.ts, 9, 14))
+>x : Symbol(x, Decl(intersectionsAndOptionalProperties.ts, 17, 7))
+>field : Symbol(To.field, Decl(intersectionsAndOptionalProperties.ts, 9, 14))
+>v.field : Symbol(field, Decl(intersectionsAndOptionalProperties.ts, 14, 14))
+>v : Symbol(v, Decl(intersectionsAndOptionalProperties.ts, 16, 13))
+>field : Symbol(field, Decl(intersectionsAndOptionalProperties.ts, 14, 14))
+}
+

tests/baselines/reference/intersectionsAndOptionalProperties.types

@@ -0,0 +1,65 @@
+=== tests/cases/compiler/intersectionsAndOptionalProperties.ts ===
+declare let x: { a?: number, b: string };
+>x : { a?: number | undefined; b: string; }
+>a : number | undefined
+>b : string
+
+declare let y: { a: null, b: string };
+>y : { a: null; b: string; }
+>a : null
+>null : null
+>b : string
+
+declare let z: { a: null } & { b: string };
+>z : { a: null; } & { b: string; }
+>a : null
+>null : null
+>b : string
+
+x = y;  // Error
+>x = y : { a: null; b: string; }
+>x : { a?: number | undefined; b: string; }
+>y : { a: null; b: string; }
+
+x = z;  // Error
+>x = z : { a: null; } & { b: string; }
+>x : { a?: number | undefined; b: string; }
+>z : { a: null; } & { b: string; }
+
+// Repro from #36604
+
+interface To {
+    field?: number;
+>field : number | undefined
+
+    anotherField: string;
+>anotherField : string
+}
+
+type From =  { field: null } & Omit<To, 'field'>;
+>From : From
+>field : null
+>null : null
+
+function foo(v: From) {
+>foo : (v: From) => void
+>v : From
+
+    let x: To;
+>x : To
+
+    x = v;  // Error
+>x = v : From
+>x : To
+>v : From
+
+    x.field = v.field; // Error
+>x.field = v.field : null
+>x.field : number | undefined
+>x : To
+>field : number | undefined
+>v.field : null
+>v : From
+>field : null
+}
+

tests/baselines/reference/normalizedIntersectionTooComplex.errors.txt

@@ -1,5 +1,5 @@
+tests/cases/compiler/normalizedIntersectionTooComplex.ts(36,14): error TS2590: Expression produces a union type that is too complex to represent.
 tests/cases/compiler/normalizedIntersectionTooComplex.ts(36,40): error TS7006: Parameter 'x' implicitly has an 'any' type.
-tests/cases/compiler/normalizedIntersectionTooComplex.ts(36,40): error TS2590: Expression produces a union type that is too complex to represent.
 
 
 ==== tests/cases/compiler/normalizedIntersectionTooComplex.ts (2 errors) ====
@@ -39,8 +39,8 @@ tests/cases/compiler/normalizedIntersectionTooComplex.ts(36,40): error TS2590: E
     declare var all: keyof Big;
     const ctor = getCtor(all);
     const comp = ctor({ common: "ok", ref: x => console.log(x) });
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2590: Expression produces a union type that is too complex to represent.
                                            ~
 !!! error TS7006: Parameter 'x' implicitly has an 'any' type.
-                                           ~~~~~~~~~~~~~~~~~~~
-!!! error TS2590: Expression produces a union type that is too complex to represent.
 

tests/baselines/reference/propTypeValidatorInference.js

@@ -14,7 +14,7 @@ export interface Validator<T> {
     [nominalTypeHack]?: T;
 }
 
-export interface Requireable<T> extends Validator<T | undefined | null> {
+export interface Requireable<T> extends Validator<T> {
     isRequired: Validator<NonNullable<T>>;
 }
 

tests/baselines/reference/propTypeValidatorInference.symbols

@@ -59,14 +59,14 @@ export interface Validator<T> {
 >T : Symbol(T, Decl(index.d.ts, 8, 27))
 }
 
-export interface Requireable<T> extends Validator<T | undefined | null> {
+export interface Requireable<T> extends Validator<T> {
 >Requireable : Symbol(Requireable, Decl(index.d.ts, 11, 1))
 >T : Symbol(T, Decl(index.d.ts, 13, 29))
 >Validator : Symbol(Validator, Decl(index.d.ts, 6, 72))
 >T : Symbol(T, Decl(index.d.ts, 13, 29))
 
     isRequired: Validator<NonNullable<T>>;
->isRequired : Symbol(Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >Validator : Symbol(Validator, Decl(index.d.ts, 6, 72))
 >NonNullable : Symbol(NonNullable, Decl(lib.es5.d.ts, --, --))
 >T : Symbol(T, Decl(index.d.ts, 13, 29))
@@ -202,11 +202,11 @@ const innerProps = {
 
     foo: PropTypes.string.isRequired,
 >foo : Symbol(foo, Decl(file.ts, 18, 20))
->PropTypes.string.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.string.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.string : Symbol(PropTypes.string, Decl(index.d.ts, 27, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >string : Symbol(PropTypes.string, Decl(index.d.ts, 27, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     bar: PropTypes.bool,
 >bar : Symbol(bar, Decl(file.ts, 19, 37))
@@ -242,11 +242,11 @@ const arrayOfTypes = [PropTypes.string, PropTypes.bool, PropTypes.shape({
 
     bar: PropTypes.number.isRequired
 >bar : Symbol(bar, Decl(file.ts, 25, 26))
->PropTypes.number.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.number.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.number : Symbol(PropTypes.number, Decl(index.d.ts, 28, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >number : Symbol(PropTypes.number, Decl(index.d.ts, 28, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
 })];
 
@@ -263,37 +263,37 @@ const propTypes: PropTypesMap = {
 
     array: PropTypes.array.isRequired,
 >array : Symbol(array, Decl(file.ts, 31, 23))
->PropTypes.array.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.array.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.array : Symbol(PropTypes.array, Decl(index.d.ts, 25, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >array : Symbol(PropTypes.array, Decl(index.d.ts, 25, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     bool: PropTypes.bool.isRequired,
 >bool : Symbol(bool, Decl(file.ts, 32, 38))
->PropTypes.bool.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.bool.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.bool : Symbol(PropTypes.bool, Decl(index.d.ts, 26, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >bool : Symbol(PropTypes.bool, Decl(index.d.ts, 26, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     shape: PropTypes.shape(innerProps).isRequired,
 >shape : Symbol(shape, Decl(file.ts, 33, 36))
->PropTypes.shape(innerProps).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.shape(innerProps).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.shape : Symbol(PropTypes.shape, Decl(index.d.ts, 28, 41))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >shape : Symbol(PropTypes.shape, Decl(index.d.ts, 28, 41))
 >innerProps : Symbol(innerProps, Decl(file.ts, 18, 5))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     oneOfType: PropTypes.oneOfType(arrayOfTypes).isRequired,
 >oneOfType : Symbol(oneOfType, Decl(file.ts, 34, 50))
->PropTypes.oneOfType(arrayOfTypes).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.oneOfType(arrayOfTypes).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.oneOfType : Symbol(PropTypes.oneOfType, Decl(index.d.ts, 29, 89))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >oneOfType : Symbol(PropTypes.oneOfType, Decl(index.d.ts, 29, 89))
 >arrayOfTypes : Symbol(arrayOfTypes, Decl(file.ts, 24, 5))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
 };
 
@@ -309,37 +309,37 @@ const propTypesWithoutAnnotation = {
 
     array: PropTypes.array.isRequired,
 >array : Symbol(array, Decl(file.ts, 40, 23))
->PropTypes.array.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.array.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.array : Symbol(PropTypes.array, Decl(index.d.ts, 25, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >array : Symbol(PropTypes.array, Decl(index.d.ts, 25, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     bool: PropTypes.bool.isRequired,
 >bool : Symbol(bool, Decl(file.ts, 41, 38))
->PropTypes.bool.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.bool.isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.bool : Symbol(PropTypes.bool, Decl(index.d.ts, 26, 12))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >bool : Symbol(PropTypes.bool, Decl(index.d.ts, 26, 12))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     shape: PropTypes.shape(innerProps).isRequired,
 >shape : Symbol(shape, Decl(file.ts, 42, 36))
->PropTypes.shape(innerProps).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.shape(innerProps).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.shape : Symbol(PropTypes.shape, Decl(index.d.ts, 28, 41))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >shape : Symbol(PropTypes.shape, Decl(index.d.ts, 28, 41))
 >innerProps : Symbol(innerProps, Decl(file.ts, 18, 5))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
     oneOfType: PropTypes.oneOfType(arrayOfTypes).isRequired,
 >oneOfType : Symbol(oneOfType, Decl(file.ts, 43, 50))
->PropTypes.oneOfType(arrayOfTypes).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>PropTypes.oneOfType(arrayOfTypes).isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 >PropTypes.oneOfType : Symbol(PropTypes.oneOfType, Decl(index.d.ts, 29, 89))
 >PropTypes : Symbol(PropTypes, Decl(file.ts, 0, 6))
 >oneOfType : Symbol(PropTypes.oneOfType, Decl(index.d.ts, 29, 89))
 >arrayOfTypes : Symbol(arrayOfTypes, Decl(file.ts, 24, 5))
->isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 73))
+>isRequired : Symbol(PropTypes.Requireable.isRequired, Decl(index.d.ts, 13, 54))
 
 };