Swift: Add a test revealing unevaluated regexs.

Author: geoffw0

swift/ql/test/library-tests/regex/parse.expected

@@ -6663,3 +6663,8 @@ regex.swift:
 
 #  254| [RegExpStar] .*
 #-----| 0 -> [RegExpDot] .
+
+#  257| [RegExpDot] .
+
+#  257| [RegExpStar] .*
+#-----| 0 -> [RegExpDot] .

swift/ql/test/library-tests/regex/regex.ql

@@ -10,7 +10,7 @@ string quote(string s) { if s.matches("% %") then result = "\"" + s + "\"" else
 
 module RegexTest implements TestSig {
   string getARelevantTag() {
-    result = ["regex", "input", "redos-vulnerable", "hasParseFailure", "modes"]
+    result = ["regex", "unevaluated-regex", "input", "redos-vulnerable", "hasParseFailure", "modes"]
   }
 
   predicate hasActualResult(Location location, string element, string tag, string value) {
@@ -47,6 +47,15 @@ module RegexTest implements TestSig {
       tag = "regex" and
       value = quote(regex.toString().replaceAll("\n", "NEWLINE"))
     )
+    or
+    exists(RegExp regex |
+      // unevaluated regex
+      not exists(RegexEval eval | eval.getARegex() = regex) and
+      location = regex.getLocation() and
+      element = regex.toString() and
+      tag = "unevaluated-regex" and
+      value = quote(regex.toString().replaceAll("\n", "NEWLINE"))
+    )
   }
 
   predicate hasOptionalResult(Location location, string element, string tag, string value) {

swift/ql/test/library-tests/regex/regex.swift

@@ -127,9 +127,9 @@ func myRegexpMethodsTests(b: Bool, str_unknown: String) throws {
 	// --- StringProtocol ---
 
 	_ = input.range(of: ".*", options: .regularExpression, range: nil, locale: nil) // $ regex=.* input=input
-	_ = input.range(of: ".*", options: .literal, range: nil, locale: nil) // (not a regular expression)
+	_ = input.range(of: ".*", options: .literal, range: nil, locale: nil) // $ SPURIOUS: unevaluated-regex=.* (not a regular expression)
 	_ = input.replacingOccurrences(of: ".*", with: "", options: .regularExpression) // $ regex=.* input=input
-	_ = input.replacingOccurrences(of: ".*", with: "", options: .literal) // (not a regular expression)
+	_ = input.replacingOccurrences(of: ".*", with: "", options: .literal) // $ SPURIOUS: unevaluated-regex=.* (not a regular expression)
 
 	// --- NSRegularExpression ---
 
@@ -151,9 +151,9 @@ func myRegexpMethodsTests(b: Bool, str_unknown: String) throws {
 	_ = inputNS.range(of: ".*", options: [.regularExpression]) // $ regex=.* input=inputNS
 	_ = inputNS.range(of: ".*", options: regexOptions) // $ regex=.* input=inputNS
 	_ = inputNS.range(of: ".*", options: regexOptions2) // $ regex=.* input=inputNS modes=IGNORECASE
-	_ = inputNS.range(of: ".*", options: .literal) // (not a regular expression)
+	_ = inputNS.range(of: ".*", options: .literal) // $ SPURIOUS: unevaluated-regex=.* (not a regular expression)
 	_ = inputNS.replacingOccurrences(of: ".*", with: "", options: .regularExpression, range: NSMakeRange(0, inputNS.length)) // $ regex=.* input=inputNS
-	_ = inputNS.replacingOccurrences(of: ".*", with: "", options: .literal, range: NSMakeRange(0, inputNS.length)) // (not a regular expression)
+	_ = inputNS.replacingOccurrences(of: ".*", with: "", options: .literal, range: NSMakeRange(0, inputNS.length)) // $ SPURIOUS: unevaluated-regex=.* (not a regular expression)
 
 	// --- flow ---
 
@@ -252,4 +252,7 @@ func myRegexpMethodsTests(b: Bool, str_unknown: String) throws {
     _ = input.replacingOccurrences(of: ".*", with: "", options: myOptions2) // $ regex=.* input=input modes=IGNORECASE
     _ = NSString(string: "abc").replacingOccurrences(of: ".*", with: "", options: [.regularExpression, .caseInsensitive], range: NSMakeRange(0, inputNS.length)) // $ regex=.* input="call to NSString.init(string:)" modes=IGNORECASE
     _ = NSString(string: "abc").replacingOccurrences(of: ".*", with: "", options: myOptions2, range: NSMakeRange(0, inputNS.length)) // $ regex=.* input="call to NSString.init(string:)" modes=IGNORECASE
+
+    // Regex created but never evaluated
+    _ = try Regex(".*") // $ unevaluated-regex=.*
 }