Swift: Add some test cases aimed at regex parsing correctness.

Author: geoffw0

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

@@ -6381,3 +6381,105 @@ regex.swift:
 
 #  172| [RegExpConstant, RegExpNormalChar] 
 #  172| bb
+
+#  180| [RegExpCharacterClass] [a-z]
+#-----| 0 -> [RegExpCharacterRange] a-z
+
+#  180| [RegExpConstant, RegExpNormalChar] a
+
+#  180| [RegExpCharacterRange] a-z
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] a
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] z
+
+#  180| [RegExpConstant, RegExpNormalChar] z
+
+#  181| [RegExpCharacterClass] [a-zA-Z]
+#-----| 0 -> [RegExpCharacterRange] a-z
+#-----| 1 -> [RegExpCharacterRange] A-Z
+
+#  181| [RegExpConstant, RegExpNormalChar] a
+
+#  181| [RegExpCharacterRange] a-z
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] a
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] z
+
+#  181| [RegExpConstant, RegExpNormalChar] z
+
+#  181| [RegExpConstant, RegExpNormalChar] A
+
+#  181| [RegExpCharacterRange] A-Z
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] A
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] Z
+
+#  181| [RegExpConstant, RegExpNormalChar] Z
+
+#  184| [RegExpCharacterClass] [a-]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] a
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] -
+
+#  184| [RegExpConstant, RegExpNormalChar] a
+
+#  184| [RegExpConstant, RegExpNormalChar] -
+
+#  185| [RegExpCharacterClass] [-a]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] -
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] a
+
+#  185| [RegExpConstant, RegExpNormalChar] -
+
+#  185| [RegExpConstant, RegExpNormalChar] a
+
+#  186| [RegExpCharacterClass] [-]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] -
+
+#  186| [RegExpConstant, RegExpNormalChar] -
+
+#  187| [RegExpCharacterClass] [*]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] *
+
+#  187| [RegExpConstant, RegExpNormalChar] *
+
+#  188| [RegExpCharacterClass] [^a]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] a
+
+#  188| [RegExpConstant, RegExpNormalChar] a
+
+#  189| [RegExpCharacterClass] [a^]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] a
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] ^
+
+#  189| [RegExpConstant, RegExpNormalChar] a
+
+#  189| [RegExpConstant, RegExpNormalChar] ^
+
+#  190| [RegExpCharacterClass] [\\]
+#-----| 0 -> [RegExpConstant, RegExpEscape] \\
+
+#  190| [RegExpConstant, RegExpEscape] \\
+
+#  191| [RegExpCharacterClass] [\\\]]
+#-----| 0 -> [RegExpConstant, RegExpEscape] \\
+#-----| 1 -> [RegExpConstant, RegExpEscape] \]
+
+#  191| [RegExpConstant, RegExpEscape] \\
+
+#  191| [RegExpConstant, RegExpEscape] \]
+
+#  192| [RegExpCharacterClass] [:]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] :
+
+#  192| [RegExpConstant, RegExpNormalChar] :
+
+#  193| [RegExpNamedCharacterProperty] [:digit:]
+
+#  194| [RegExpNamedCharacterProperty] [:alnum:]
+
+#  197| [RegExpCharacterClass] []a]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] ]
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] a
+
+#  197| [RegExpConstant, RegExpNormalChar] ]
+
+#  197| [RegExpConstant, RegExpNormalChar] a
+
+#  198| [RegExpNamedCharacterProperty] [:aaaaa:]

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

@@ -173,4 +173,27 @@ func myRegexpMethodsTests(b: Bool, str_unknown: String) throws {
 		aa|
 		bb
 		""").firstMatch(in: input) // $ input=input regex=aa|NEWLINEbb
+
+    // --- exploring parser correctness ---
+
+    // ranges
+    _ = try Regex("[a-z]").firstMatch(in: input) // $ input=input regex=[a-z]
+    _ = try Regex("[a-zA-Z]").firstMatch(in: input) // $ input=input regex=[a-zA-Z]
+
+    // character classes
+    _ = try Regex("[a-]").firstMatch(in: input) // $ input=input regex=[a-]
+    _ = try Regex("[-a]").firstMatch(in: input) // $ input=input regex=[-a]
+    _ = try Regex("[-]").firstMatch(in: input) // $ input=input regex=[-]
+    _ = try Regex("[*]").firstMatch(in: input) // $ input=input regex=[*]
+    _ = try Regex("[^a]").firstMatch(in: input) // $ input=input regex=[^a]
+    _ = try Regex("[a^]").firstMatch(in: input) // $ input=input regex=[a^]
+    _ = try Regex(#"[\\]"#).firstMatch(in: input) // $ input=input regex=[\\]
+    _ = try Regex(#"[\\\]]"#).firstMatch(in: input) // $ input=input regex=[\\\]]
+    _ = try Regex("[:]").firstMatch(in: input) // $ input=input regex=[:]
+    _ = try Regex("[:digit:]").firstMatch(in: input) // $ input=input regex=[:digit:] SPURIOUS: $hasParseFailure
+    _ = try Regex("[:alnum:]").firstMatch(in: input) // $ input=input regex=[:alnum:] SPURIOUS: $hasParseFailure
+
+	// invalid (Swift doesn't like these regexs)
+    _ = try Regex("[]a]").firstMatch(in: input) // this is valid in other regex implementations, and is likely harmless to accept
+    _ = try Regex("[:aaaaa:]").firstMatch(in: input) // $ hasParseFailure
 }