unified: Document lack of support for properties

Author: asgerf

unified/ql/lib/codeql/unified/internal/mad/LegacyMaD.qll

@@ -29,6 +29,7 @@ private predicate modelContainsMethodName(string name) {
 }
 
 private predicate parsedRawMethodName(string rawName, string name, string argLabels) {
+  // NOTE: We only support method names at the moment, not property names like `String.count`.
   modelContainsMethodName(rawName) and
   exists(string regex |
     regex = "([^(]+)\\((.*)\\)" and

unified/ql/test/library-tests/mad/test.swift

@@ -31,3 +31,28 @@ func test(url: URL, string: String) {
         }
     }
 }
+
+class UITextField {
+    var text: String = ""
+}
+
+class URLSessionConfiguration {
+    var tlsMaximumSupportedProtocol: Int = 0
+    var tlsMinimumSupportedProtocol: Int = 0
+    var tlsMaximumSupportedProtocolVersion: Int = 0
+    var tlsMinimumSupportedProtocolVersion: Int = 0
+}
+
+func testProperties(
+    string: String,
+    textField: UITextField,
+    configuration: URLSessionConfiguration
+) {
+    _ = string.count  // $ MISSING: isSource=string-length
+    _ = textField.text  // $ MISSING: isSource=local
+
+    configuration.tlsMaximumSupportedProtocol = 0  // $ MISSING: isSink=tls-protocol-version
+    configuration.tlsMinimumSupportedProtocol = 0  // $ MISSING: isSink=tls-protocol-version
+    configuration.tlsMaximumSupportedProtocolVersion = 0  // $ MISSING: isSink=tls-protocol-version
+    configuration.tlsMinimumSupportedProtocolVersion = 0  // $ MISSING: isSink=tls-protocol-version
+}