Fixed inconsistent type compatibility for a type with a call signature and and index signature (microsoft#23226)

Author: dragomirtitian

src/compiler/checker.ts

@@ -11451,9 +11451,17 @@ namespace ts {
 
         /**
          * Return true if type was inferred from an object literal, written as an object type literal, or is the shape of a module
-         * with no call or construct signatures.
+         * with no call or construct signatures, or is an intersection type and one of the constituents of the intersection satisfies any on the previous rules.
          */
         function isObjectTypeWithInferableIndex(type: Type) {
+            if (type.flags & TypeFlags.Intersection) {
+                for (const t of (<IntersectionType>type).types) {
+                    if (isObjectTypeWithInferableIndex(t)) {
+                        return true;
+                    }
+                }
+                return false;
+            }
             return type.symbol && (type.symbol.flags & (SymbolFlags.ObjectLiteral | SymbolFlags.TypeLiteral | SymbolFlags.ValueModule)) !== 0 &&
                 !typeHasCallOrConstructSignatures(type);
         }

tests/baselines/reference/stringIndexerAndCallSignature.js

@@ -0,0 +1,12 @@
+//// [stringIndexerAndCallSignature.ts]
+type I = {
+    (): string;
+    [name: string]: number;
+}
+
+declare let val: { (): string } & { foo: number; }
+let a: I = val;
+
+
+//// [stringIndexerAndCallSignature.js]
+var a = val;

tests/baselines/reference/stringIndexerAndCallSignature.symbols

@@ -0,0 +1,18 @@
+=== tests/cases/compiler/stringIndexerAndCallSignature.ts ===
+type I = {
+>I : Symbol(I, Decl(stringIndexerAndCallSignature.ts, 0, 0))
+
+    (): string;
+    [name: string]: number;
+>name : Symbol(name, Decl(stringIndexerAndCallSignature.ts, 2, 5))
+}
+
+declare let val: { (): string } & { foo: number; }
+>val : Symbol(val, Decl(stringIndexerAndCallSignature.ts, 5, 11))
+>foo : Symbol(foo, Decl(stringIndexerAndCallSignature.ts, 5, 35))
+
+let a: I = val;
+>a : Symbol(a, Decl(stringIndexerAndCallSignature.ts, 6, 3))
+>I : Symbol(I, Decl(stringIndexerAndCallSignature.ts, 0, 0))
+>val : Symbol(val, Decl(stringIndexerAndCallSignature.ts, 5, 11))
+

tests/baselines/reference/stringIndexerAndCallSignature.types

@@ -0,0 +1,18 @@
+=== tests/cases/compiler/stringIndexerAndCallSignature.ts ===
+type I = {
+>I : I
+
+    (): string;
+    [name: string]: number;
+>name : string
+}
+
+declare let val: { (): string } & { foo: number; }
+>val : (() => string) & { foo: number; }
+>foo : number
+
+let a: I = val;
+>a : I
+>I : I
+>val : (() => string) & { foo: number; }
+

tests/cases/compiler/stringIndexerAndCallSignature.ts

@@ -0,0 +1,7 @@
+type I = {
+    (): string;
+    [name: string]: number;
+}
+
+declare let val: { (): string } & { foo: number; }
+let a: I = val;