feat: enum expressions (#1956)

* feat: enum expressions

Author: Zamiell

src/lib/converter/symbols.ts

@@ -868,10 +868,17 @@ function isEnumLike(checker: ts.TypeChecker, type: ts.Type, location: ts.Node) {
 
     return type.getProperties().every((prop) => {
         const propType = checker.getTypeOfSymbolAtLocation(prop, location);
-        return propType.isStringLiteral() || propType.isNumberLiteral();
+        return isValidEnumProperty(propType);
     });
 }
 
+function isValidEnumProperty(type: ts.Type) {
+    return hasAnyFlag(
+        type.flags,
+        ts.TypeFlags.NumberLike | ts.TypeFlags.StringLike
+    );
+}
+
 function convertVariableAsEnum(
     context: Context,
     symbol: ts.Symbol,
@@ -899,10 +906,12 @@ function convertVariableAsEnum(
             prop,
             declaration
         );
-        assert(propType.isStringLiteral() || propType.isNumberLiteral());
 
-        reflection.defaultValue = JSON.stringify(propType.value);
-        reflection.type = new LiteralType(propType.value);
+        reflection.type = context.converter.convertType(context, propType);
+
+        if (propType.isStringLiteral() || propType.isNumberLiteral()) {
+            reflection.defaultValue = JSON.stringify(propType.value);
+        }
 
         rc.finalizeDeclarationReflection(reflection, prop, void 0);
     }

src/test/behaviorTests.ts

@@ -80,6 +80,23 @@ export const behaviorTests: Record<
             ReflectionKind.Enum,
             "WithoutReadonlyNumeric"
         );
+
+        const WithInvalidTypeUnionMember = query(
+            project,
+            "WithInvalidTypeUnionMember"
+        );
+        equal(
+            WithInvalidTypeUnionMember.kind,
+            ReflectionKind.Variable,
+            "WithInvalidTypeUnionMember"
+        );
+
+        const WithNumericExpression = query(project, "WithNumericExpression");
+        equal(
+            WithNumericExpression.kind,
+            ReflectionKind.Enum,
+            "WithNumericExpression"
+        );
     },
 
     declareGlobal(project) {