test: Add test for string matching

Add test for regex (?!) to not match a specific sequence.
This is useful to exclude specific matches while using
wildcard patterns.

Change-Id: I54aec4b5a956af0e815b7a57c715f4f58af8a4e6
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
diff --git a/test/test_entity-manager.cpp b/test/test_entity-manager.cpp
index 4cd841a..1f73607 100644
--- a/test/test_entity-manager.cpp
+++ b/test/test_entity-manager.cpp
@@ -267,6 +267,15 @@
     EXPECT_FALSE(matchProbe(j, v));
 }
 
+TEST(MatchProbe, stringRegexNotPrefix)
+{
+    nlohmann::json j = R"("foo(?!bar)...foo")"_json;
+    DBusValueVariant v1 = "foobarfoo"s;
+    DBusValueVariant v2 = "foofoofoo"s;
+    EXPECT_FALSE(matchProbe(j, v1));
+    EXPECT_TRUE(matchProbe(j, v2));
+}
+
 TEST(MatchProbe, stringZeroNeqFalse)
 {
     nlohmann::json j = R"("0")"_json;