fix(48556): never cannot be spread into object, but it can be spread into JSX props

src/compiler/checker.ts

@@ -27877,6 +27877,7 @@ namespace ts {
                         }
                     }
                     else {
+                        error(attributeDecl.expression, Diagnostics.Spread_types_may_only_be_created_from_object_types);
                         typeToIntersect = typeToIntersect ? getIntersectionType([typeToIntersect, exprType]) : exprType;
                     }
                 }

tests/baselines/reference/correctlyMarkAliasAsReferences3.errors.txt

@@ -0,0 +1,18 @@
+tests/cases/conformance/jsx/0.tsx(6,21): error TS2698: Spread types may only be created from object types.
+
+
+==== tests/cases/conformance/jsx/0.tsx (1 errors) ====
+    ///<reference path="declaration.d.ts" />
+    import * as cx from 'classnames';
+    import * as React from "react";
+
+    let buttonProps;
+    let k = <button {...buttonProps}>
+                        ~~~~~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
+                <span className={cx('class1', { class2: true })} />
+            </button>;
+
+==== tests/cases/conformance/jsx/declaration.d.ts (0 errors) ====
+    declare module "classnames";
+

tests/baselines/reference/jsxExcessPropsAndAssignability.errors.txt

@@ -1,8 +1,10 @@
+tests/cases/compiler/jsxExcessPropsAndAssignability.tsx(14,27): error TS2698: Spread types may only be created from object types.
 tests/cases/compiler/jsxExcessPropsAndAssignability.tsx(16,6): error TS2322: Type 'ComposedComponentProps & { myProp: number; }' is not assignable to type 'IntrinsicAttributes & IntrinsicClassAttributes<Component<WrapperComponentProps, any, any>> & Readonly<{ children?: ReactNode; }> & Readonly<WrapperComponentProps>'.
   Type 'ComposedComponentProps & { myProp: number; }' is not assignable to type 'Readonly<WrapperComponentProps>'.
+tests/cases/compiler/jsxExcessPropsAndAssignability.tsx(16,27): error TS2698: Spread types may only be created from object types.
 
 
-==== tests/cases/compiler/jsxExcessPropsAndAssignability.tsx (1 errors) ====
+==== tests/cases/compiler/jsxExcessPropsAndAssignability.tsx (3 errors) ====
     /// <reference path="/.lib/react16.d.ts" />
 
     import * as React from 'react';
@@ -17,10 +19,14 @@ tests/cases/compiler/jsxExcessPropsAndAssignability.tsx(16,6): error TS2322: Typ
 
         // Expected no error, got none - good
         <WrapperComponent {...props} myProp={'1000000'} />;
+                              ~~~~~
+!!! error TS2698: Spread types may only be created from object types.
         // Expected error, but got none - bad!
         <WrapperComponent {...props} myProp={1000000} />;
          ~~~~~~~~~~~~~~~~
 !!! error TS2322: Type 'ComposedComponentProps & { myProp: number; }' is not assignable to type 'IntrinsicAttributes & IntrinsicClassAttributes<Component<WrapperComponentProps, any, any>> & Readonly<{ children?: ReactNode; }> & Readonly<WrapperComponentProps>'.
 !!! error TS2322:   Type 'ComposedComponentProps & { myProp: number; }' is not assignable to type 'Readonly<WrapperComponentProps>'.
+                              ~~~~~
+!!! error TS2698: Spread types may only be created from object types.
     };
 

tests/baselines/reference/jsxNamespacePrefixInName.errors.txt

@@ -19,6 +19,7 @@ tests/cases/compiler/jsxNamespacePrefixInName.tsx(21,21): error TS1003: Identifi
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(22,26): error TS1003: Identifier expected.
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(22,27): error TS1003: Identifier expected.
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(22,29): error TS1005: '...' expected.
+tests/cases/compiler/jsxNamespacePrefixInName.tsx(22,29): error TS2698: Spread types may only be created from object types.
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(24,21): error TS1109: Expression expected.
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(24,22): error TS1109: Expression expected.
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(24,25): error TS1005: ',' expected.
@@ -29,7 +30,7 @@ tests/cases/compiler/jsxNamespacePrefixInName.tsx(24,42): error TS1109: Expressi
 tests/cases/compiler/jsxNamespacePrefixInName.tsx(25,24): error TS1003: Identifier expected.
 
 
-==== tests/cases/compiler/jsxNamespacePrefixInName.tsx (29 errors) ====
+==== tests/cases/compiler/jsxNamespacePrefixInName.tsx (30 errors) ====
     var justElement1 = <a:element />;
     var justElement2 = <a:element></a:element>;
     var justElement3 = <a:element attr={"value"}></a:element>;
@@ -94,6 +95,8 @@ tests/cases/compiler/jsxNamespacePrefixInName.tsx(25,24): error TS1003: Identifi
 !!! error TS1003: Identifier expected.
                                 ~~~~~~~
 !!! error TS1005: '...' expected.
+                                ~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
 
     var beginOfIdent1 = <:a attr={"value"} />;
                         ~

tests/baselines/reference/jsxNamespacePrefixInNameReact.errors.txt

@@ -19,6 +19,7 @@ tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(23,21): error TS1003: Ide
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(24,26): error TS1003: Identifier expected.
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(24,27): error TS1003: Identifier expected.
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(24,29): error TS1005: '...' expected.
+tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(24,29): error TS2698: Spread types may only be created from object types.
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(26,21): error TS1109: Expression expected.
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(26,22): error TS1109: Expression expected.
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(26,25): error TS1005: ',' expected.
@@ -29,7 +30,7 @@ tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(26,42): error TS1109: Exp
 tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(27,24): error TS1003: Identifier expected.
 
 
-==== tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx (29 errors) ====
+==== tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx (30 errors) ====
     declare var React: any;
 
     var justElement1 = <a:element />;
@@ -96,6 +97,8 @@ tests/cases/compiler/jsxNamespacePrefixInNameReact.tsx(27,24): error TS1003: Ide
 !!! error TS1003: Identifier expected.
                                 ~~~~~~~
 !!! error TS1005: '...' expected.
+                                ~~~~~~~
+!!! error TS2698: Spread types may only be created from object types.
 
     var beginOfIdent1 = <:a attr={"value"} />;
                         ~

tests/baselines/reference/tsxSpreadInvalidType.errors.txt

@@ -0,0 +1,24 @@
+tests/cases/conformance/jsx/a.tsx(9,21): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/jsx/a.tsx(10,21): error TS2698: Spread types may only be created from object types.
+tests/cases/conformance/jsx/a.tsx(11,21): error TS2698: Spread types may only be created from object types.
+
+
+==== tests/cases/conformance/jsx/a.tsx (3 errors) ====
+    namespace JSX {
+        export interface IntrinsicElements { [key: string]: any }
+    }
+
+    const a = {} as never;
+    const b = null;
+    const c = undefined;
+
+    const d = <div { ...a } />
+                        ~
+!!! error TS2698: Spread types may only be created from object types.
+    const e = <div { ...b } />
+                        ~
+!!! error TS2698: Spread types may only be created from object types.
+    const f = <div { ...c } />
+                        ~
+!!! error TS2698: Spread types may only be created from object types.
+

tests/baselines/reference/tsxSpreadInvalidType.js

@@ -0,0 +1,22 @@
+//// [a.tsx]
+namespace JSX {
+    export interface IntrinsicElements { [key: string]: any }
+}
+
+const a = {} as never;
+const b = null;
+const c = undefined;
+
+const d = <div { ...a } />
+const e = <div { ...b } />
+const f = <div { ...c } />
+
+
+//// [a.jsx]
+"use strict";
+var a = {};
+var b = null;
+var c = undefined;
+var d = <div {...a}/>;
+var e = <div {...b}/>;
+var f = <div {...c}/>;

tests/baselines/reference/tsxSpreadInvalidType.symbols

@@ -0,0 +1,34 @@
+=== tests/cases/conformance/jsx/a.tsx ===
+namespace JSX {
+>JSX : Symbol(JSX, Decl(a.tsx, 0, 0))
+
+    export interface IntrinsicElements { [key: string]: any }
+>IntrinsicElements : Symbol(IntrinsicElements, Decl(a.tsx, 0, 15))
+>key : Symbol(key, Decl(a.tsx, 1, 42))
+}
+
+const a = {} as never;
+>a : Symbol(a, Decl(a.tsx, 4, 5))
+
+const b = null;
+>b : Symbol(b, Decl(a.tsx, 5, 5))
+
+const c = undefined;
+>c : Symbol(c, Decl(a.tsx, 6, 5))
+>undefined : Symbol(undefined)
+
+const d = <div { ...a } />
+>d : Symbol(d, Decl(a.tsx, 8, 5))
+>div : Symbol(JSX.IntrinsicElements, Decl(a.tsx, 0, 15))
+>a : Symbol(a, Decl(a.tsx, 4, 5))
+
+const e = <div { ...b } />
+>e : Symbol(e, Decl(a.tsx, 9, 5))
+>div : Symbol(JSX.IntrinsicElements, Decl(a.tsx, 0, 15))
+>b : Symbol(b, Decl(a.tsx, 5, 5))
+
+const f = <div { ...c } />
+>f : Symbol(f, Decl(a.tsx, 10, 5))
+>div : Symbol(JSX.IntrinsicElements, Decl(a.tsx, 0, 15))
+>c : Symbol(c, Decl(a.tsx, 6, 5))
+

tests/baselines/reference/tsxSpreadInvalidType.types

@@ -0,0 +1,37 @@
+=== tests/cases/conformance/jsx/a.tsx ===
+namespace JSX {
+    export interface IntrinsicElements { [key: string]: any }
+>key : string
+}
+
+const a = {} as never;
+>a : never
+>{} as never : never
+>{} : {}
+
+const b = null;
+>b : null
+>null : null
+
+const c = undefined;
+>c : undefined
+>undefined : undefined
+
+const d = <div { ...a } />
+>d : any
+><div { ...a } /> : any
+>div : any
+>a : never
+
+const e = <div { ...b } />
+>e : any
+><div { ...b } /> : any
+>div : any
+>b : null
+
+const f = <div { ...c } />
+>f : any
+><div { ...c } /> : any
+>div : any
+>c : undefined
+

tests/cases/conformance/jsx/tsxSpreadInvalidType.tsx

@@ -0,0 +1,14 @@
+// @jsx: preserve
+// @strict: true
+// @filename: a.tsx
+namespace JSX {
+    export interface IntrinsicElements { [key: string]: any }
+}
+
+const a = {} as never;
+const b = null;
+const c = undefined;
+
+const d = <div { ...a } />
+const e = <div { ...b } />
+const f = <div { ...c } />