Function isWeakType

test/fixtures/snapshot/typescript.js:66948–66958

* A type is 'weak' if it is an object type with at least one optional property * and no required properties, call/construct signatures or index signatures

(type)

         * and no required properties, call/construct signatures or index signatures
         */
        function isWeakType(type) {
            if (type.flags & 524288 /* TypeFlags.Object */) {
                var resolved = resolveStructuredTypeMembers(type);
                return resolved.callSignatures.length === 0 && resolved.constructSignatures.length === 0 && resolved.indexInfos.length === 0 &&
                    resolved.properties.length > 0 && ts.every(resolved.properties, function (p) { return !!(p.flags & 16777216 /* SymbolFlags.Optional */); });
            }
            if (type.flags & 2097152 /* TypeFlags.Intersection */) {
                return ts.every(type.types, isWeakType);
            }
            return false;
        }
        function hasCommonProperties(source, target, isComparingJsxAttributes) {
            for (var _i = 0, _a = getPropertiesOfType(source); _i < _a.length; _i++) {
                var prop = _a[_i];