Add regression test

tests/baselines/reference/intersectionsAndOptionalProperties.errors.txt

@@ -46,4 +46,9 @@ tests/cases/compiler/intersectionsAndOptionalProperties.ts(20,5): error TS2322:
         ~~~~~~~
 !!! error TS2322: Type 'null' is not assignable to type 'number | undefined'.
     }
+    
+    // Repro from #38348
+    
+    const yy: number[] & [number, ...number[]] = [1];
+    const xx: [number, ...number[]] = yy;
     

tests/baselines/reference/intersectionsAndOptionalProperties.js

@@ -20,6 +20,11 @@ function foo(v: From) {
     x = v;  // Error
     x.field = v.field; // Error
 }
+
+// Repro from #38348
+
+const yy: number[] & [number, ...number[]] = [1];
+const xx: [number, ...number[]] = yy;
 
 
 //// [intersectionsAndOptionalProperties.js]
@@ -31,3 +36,6 @@ function foo(v) {
     x = v; // Error
     x.field = v.field; // Error
 }
+// Repro from #38348
+var yy = [1];
+var xx = yy;

tests/baselines/reference/intersectionsAndOptionalProperties.symbols

@@ -62,3 +62,12 @@ function foo(v: From) {
 >field : Symbol(field, Decl(intersectionsAndOptionalProperties.ts, 14, 14))
 }
 
+// Repro from #38348
+
+const yy: number[] & [number, ...number[]] = [1];
+>yy : Symbol(yy, Decl(intersectionsAndOptionalProperties.ts, 24, 5))
+
+const xx: [number, ...number[]] = yy;
+>xx : Symbol(xx, Decl(intersectionsAndOptionalProperties.ts, 25, 5))
+>yy : Symbol(yy, Decl(intersectionsAndOptionalProperties.ts, 24, 5))
+

tests/baselines/reference/intersectionsAndOptionalProperties.types

@@ -63,3 +63,14 @@ function foo(v: From) {
 >field : null
 }
 
+// Repro from #38348
+
+const yy: number[] & [number, ...number[]] = [1];
+>yy : number[] & [number, ...number[]]
+>[1] : [number]
+>1 : 1
+
+const xx: [number, ...number[]] = yy;
+>xx : [number, ...number[]]
+>yy : number[] & [number, ...number[]]
+

tests/cases/compiler/intersectionsAndOptionalProperties.ts

@@ -21,3 +21,8 @@ function foo(v: From) {
     x = v;  // Error
     x.field = v.field; // Error
 }
+
+// Repro from #38348
+
+const yy: number[] & [number, ...number[]] = [1];
+const xx: [number, ...number[]] = yy;