No excess property error for spread properties (microsoft#26798)

That is, properties in an object literal type that came from a spread
assignment never cause an excess property error.

Author: sandersn

src/compiler/checker.ts

@@ -11328,7 +11328,7 @@ namespace ts {
                         return hasExcessProperties(source, discriminant, /*discriminant*/ undefined, reportErrors);
                     }
                     for (const prop of getPropertiesOfObjectType(source)) {
-                        if (!isKnownProperty(target, prop.escapedName, isComparingJsxAttributes)) {
+                        if (!isPropertyFromSpread(prop, source.symbol) && !isKnownProperty(target, prop.escapedName, isComparingJsxAttributes)) {
                             if (reportErrors) {
                                 // We know *exactly* where things went wrong when comparing the types.
                                 // Use this property as the error node as this will be more helpful in
@@ -11372,6 +11372,10 @@ namespace ts {
                 return false;
             }
 
+            function isPropertyFromSpread(prop: Symbol, container: Symbol) {
+                return prop.valueDeclaration && container.valueDeclaration && prop.valueDeclaration.parent !== container.valueDeclaration;
+            }
+
             function eachTypeRelatedToSomeType(source: UnionOrIntersectionType, target: UnionOrIntersectionType): Ternary {
                 let result = Ternary.True;
                 const sourceTypes = source.types;

tests/baselines/reference/objectSpreadNegative.errors.txt

@@ -18,15 +18,9 @@ tests/cases/conformance/types/spread/objectSpreadNegative.ts(53,9): error TS2339
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(58,11): error TS2339: Property 'a' does not exist on type '{}'.
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(62,14): error TS2698: Spread types may only be created from object types.
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(65,14): error TS2698: Spread types may only be created from object types.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(79,37): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(82,7): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(84,7): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
 
 
-==== tests/cases/conformance/types/spread/objectSpreadNegative.ts (20 errors) ====
+==== tests/cases/conformance/types/spread/objectSpreadNegative.ts (17 errors) ====
     let o = { a: 1, b: 'no' }
 
     /// private propagates
@@ -138,23 +132,4 @@ tests/cases/conformance/types/spread/objectSpreadNegative.ts(84,7): error TS2322
         f({ a: 1 }, { a: 'mismatch' })
     let overwriteId: { id: string, a: number, c: number, d: string } =
         f({ a: 1, id: true }, { c: 1, d: 'no' })
-    
-    // excess property checks
-    type A = { a: string, b: string };
-    type Extra = { a: string, b: string, extra: string };
-    const extra1: A = { a: "a", b: "b", extra: "extra" };
-                                        ~~~~~~~~~~~~~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-    const extra2 = { a: "a", b: "b", extra: "extra" };
-    const a1: A = { ...extra1 }; // error spans should be here
-    const a2: A = { ...extra2 }; // not on the symbol declarations above
-          ~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-    const extra3: Extra = { a: "a", b: "b", extra: "extra" };
-    const a3: A = { ...extra3 }; // same here
-          ~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
 

tests/baselines/reference/objectSpreadNegative.js

@@ -73,16 +73,6 @@ let overlapConflict: { id:string, a: string } =
     f({ a: 1 }, { a: 'mismatch' })
 let overwriteId: { id: string, a: number, c: number, d: string } =
     f({ a: 1, id: true }, { c: 1, d: 'no' })
-
-// excess property checks
-type A = { a: string, b: string };
-type Extra = { a: string, b: string, extra: string };
-const extra1: A = { a: "a", b: "b", extra: "extra" };
-const extra2 = { a: "a", b: "b", extra: "extra" };
-const a1: A = { ...extra1 }; // error spans should be here
-const a2: A = { ...extra2 }; // not on the symbol declarations above
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
-const a3: A = { ...extra3 }; // same here
 
 
 //// [objectSpreadNegative.js]
@@ -167,9 +157,3 @@ var exclusive = f({ a: 1, b: 'yes' }, { c: 'no', d: false });
 var overlap = f({ a: 1 }, { a: 2, b: 'extra' });
 var overlapConflict = f({ a: 1 }, { a: 'mismatch' });
 var overwriteId = f({ a: 1, id: true }, { c: 1, d: 'no' });
-var extra1 = { a: "a", b: "b", extra: "extra" };
-var extra2 = { a: "a", b: "b", extra: "extra" };
-var a1 = __assign({}, extra1); // error spans should be here
-var a2 = __assign({}, extra2); // not on the symbol declarations above
-var extra3 = { a: "a", b: "b", extra: "extra" };
-var a3 = __assign({}, extra3); // same here

tests/baselines/reference/objectSpreadNegative.symbols

@@ -243,50 +243,3 @@ let overwriteId: { id: string, a: number, c: number, d: string } =
 >c : Symbol(c, Decl(objectSpreadNegative.ts, 73, 27))
 >d : Symbol(d, Decl(objectSpreadNegative.ts, 73, 33))
 
-// excess property checks
-type A = { a: string, b: string };
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 76, 10))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 76, 21))
-
-type Extra = { a: string, b: string, extra: string };
->Extra : Symbol(Extra, Decl(objectSpreadNegative.ts, 76, 34))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 77, 14))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 77, 25))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 77, 36))
-
-const extra1: A = { a: "a", b: "b", extra: "extra" };
->extra1 : Symbol(extra1, Decl(objectSpreadNegative.ts, 78, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 78, 19))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 78, 27))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 78, 35))
-
-const extra2 = { a: "a", b: "b", extra: "extra" };
->extra2 : Symbol(extra2, Decl(objectSpreadNegative.ts, 79, 5))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 79, 16))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 79, 24))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 79, 32))
-
-const a1: A = { ...extra1 }; // error spans should be here
->a1 : Symbol(a1, Decl(objectSpreadNegative.ts, 80, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra1 : Symbol(extra1, Decl(objectSpreadNegative.ts, 78, 5))
-
-const a2: A = { ...extra2 }; // not on the symbol declarations above
->a2 : Symbol(a2, Decl(objectSpreadNegative.ts, 81, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra2 : Symbol(extra2, Decl(objectSpreadNegative.ts, 79, 5))
-
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
->extra3 : Symbol(extra3, Decl(objectSpreadNegative.ts, 82, 5))
->Extra : Symbol(Extra, Decl(objectSpreadNegative.ts, 76, 34))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 82, 23))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 82, 31))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 82, 39))
-
-const a3: A = { ...extra3 }; // same here
->a3 : Symbol(a3, Decl(objectSpreadNegative.ts, 83, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra3 : Symbol(extra3, Decl(objectSpreadNegative.ts, 82, 5))
-

tests/baselines/reference/objectSpreadNegative.types

@@ -325,60 +325,3 @@ let overwriteId: { id: string, a: number, c: number, d: string } =
 >d : string
 >'no' : "no"
 
-// excess property checks
-type A = { a: string, b: string };
->A : A
->a : string
->b : string
-
-type Extra = { a: string, b: string, extra: string };
->Extra : Extra
->a : string
->b : string
->extra : string
-
-const extra1: A = { a: "a", b: "b", extra: "extra" };
->extra1 : A
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const extra2 = { a: "a", b: "b", extra: "extra" };
->extra2 : { a: string; b: string; extra: string; }
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const a1: A = { ...extra1 }; // error spans should be here
->a1 : A
->{ ...extra1 } : { a: string; b: string; }
->extra1 : A
-
-const a2: A = { ...extra2 }; // not on the symbol declarations above
->a2 : A
->{ ...extra2 } : { a: string; b: string; extra: string; }
->extra2 : { a: string; b: string; extra: string; }
-
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
->extra3 : Extra
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const a3: A = { ...extra3 }; // same here
->a3 : A
->{ ...extra3 } : { a: string; b: string; extra: string; }
->extra3 : Extra
-

tests/baselines/reference/spreadExcessProperty.js

@@ -0,0 +1,20 @@
+//// [spreadExcessProperty.ts]
+type A = { a: string, b: string };
+const extra1 = { a: "a", b: "b", extra: "extra" };
+const a1: A = { ...extra1 }; // spread should not give excess property errors
+
+
+//// [spreadExcessProperty.js]
+var __assign = (this && this.__assign) || function () {
+    __assign = Object.assign || function(t) {
+        for (var s, i = 1, n = arguments.length; i < n; i++) {
+            s = arguments[i];
+            for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+                t[p] = s[p];
+        }
+        return t;
+    };
+    return __assign.apply(this, arguments);
+};
+var extra1 = { a: "a", b: "b", extra: "extra" };
+var a1 = __assign({}, extra1); // spread should not give excess property errors

tests/baselines/reference/spreadExcessProperty.symbols

@@ -0,0 +1,17 @@
+=== tests/cases/conformance/types/spread/spreadExcessProperty.ts ===
+type A = { a: string, b: string };
+>A : Symbol(A, Decl(spreadExcessProperty.ts, 0, 0))
+>a : Symbol(a, Decl(spreadExcessProperty.ts, 0, 10))
+>b : Symbol(b, Decl(spreadExcessProperty.ts, 0, 21))
+
+const extra1 = { a: "a", b: "b", extra: "extra" };
+>extra1 : Symbol(extra1, Decl(spreadExcessProperty.ts, 1, 5))
+>a : Symbol(a, Decl(spreadExcessProperty.ts, 1, 16))
+>b : Symbol(b, Decl(spreadExcessProperty.ts, 1, 24))
+>extra : Symbol(extra, Decl(spreadExcessProperty.ts, 1, 32))
+
+const a1: A = { ...extra1 }; // spread should not give excess property errors
+>a1 : Symbol(a1, Decl(spreadExcessProperty.ts, 2, 5))
+>A : Symbol(A, Decl(spreadExcessProperty.ts, 0, 0))
+>extra1 : Symbol(extra1, Decl(spreadExcessProperty.ts, 1, 5))
+

tests/baselines/reference/spreadExcessProperty.types

@@ -0,0 +1,21 @@
+=== tests/cases/conformance/types/spread/spreadExcessProperty.ts ===
+type A = { a: string, b: string };
+>A : A
+>a : string
+>b : string
+
+const extra1 = { a: "a", b: "b", extra: "extra" };
+>extra1 : { a: string; b: string; extra: string; }
+>{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
+>a : string
+>"a" : "a"
+>b : string
+>"b" : "b"
+>extra : string
+>"extra" : "extra"
+
+const a1: A = { ...extra1 }; // spread should not give excess property errors
+>a1 : A
+>{ ...extra1 } : { a: string; b: string; extra: string; }
+>extra1 : { a: string; b: string; extra: string; }
+

tests/cases/conformance/types/spread/objectSpreadNegative.ts

@@ -73,13 +73,3 @@ let overlapConflict: { id:string, a: string } =
     f({ a: 1 }, { a: 'mismatch' })
 let overwriteId: { id: string, a: number, c: number, d: string } =
     f({ a: 1, id: true }, { c: 1, d: 'no' })
-
-// excess property checks
-type A = { a: string, b: string };
-type Extra = { a: string, b: string, extra: string };
-const extra1: A = { a: "a", b: "b", extra: "extra" };
-const extra2 = { a: "a", b: "b", extra: "extra" };
-const a1: A = { ...extra1 }; // error spans should be here
-const a2: A = { ...extra2 }; // not on the symbol declarations above
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
-const a3: A = { ...extra3 }; // same here

tests/cases/conformance/types/spread/spreadExcessProperty.ts

@@ -0,0 +1,3 @@
+type A = { a: string, b: string };
+const extra1 = { a: "a", b: "b", extra: "extra" };
+const a1: A = { ...extra1 }; // spread should not give excess property errors