Added tests for FindString

re_test.go

@@ -204,6 +204,28 @@ func TestFindAllMatches(t *testing.T) {
 	}
 }
 
+func TestFindString(t *testing.T) {
+	for _, test := range reTests {
+		t.Run(test.re+"	"+test.str, func(t *testing.T) {
+			regComp, err := Compile(test.re)
+			if err != nil {
+				panic(err)
+			}
+			foundString := FindString(regComp, test.str)
+			if len(test.result) == 0 {
+				if foundString != "" {
+					t.Errorf("Expected no match got %v\n", foundString)
+				}
+			} else {
+				expectedString := test.str[test.result[0].startIdx:test.result[0].endIdx]
+				if foundString != foundString {
+					t.Errorf("Wanted %v	Got %v\n", expectedString, foundString)
+				}
+			}
+		})
+	}
+}
+
 func TestFindAllGroups(t *testing.T) {
 	for _, test := range groupTests {
 		t.Run(test.re+"	"+test.str, func(t *testing.T) {