fix: handle epsilon transitions

.gitignore

@@ -112,3 +112,4 @@ package-lock.json
 yarn.lock
 
 index.node
+.yarn/

package.json

@@ -51,5 +51,6 @@
     },
     "engines": {
         "yarn": "^1.22.0"
-    }
-}
+    },
+    "packageManager": "[email protected]"
+}

packages/compiler/src/dfa_tests.json

@@ -37,5 +37,21 @@
         "regex": "^[a-zA-Z]{2,}\\s[a-zA-Z]{1,}'?-?[a-zA-Z]{2,}\\s?([a-zA-Z]{1,})?$",
         "pass": ["John Doe", "Mary Jane", "Robert O'Neill", "Sarah Jane-Smith"],
         "fail": ["J D", "John", "John  Doe", "12John Doe"]
+    },
+    {
+        "regex": "(\r\n|^)to:([^\r\n]+<)?([^@]{1,3})([^@]*)@([a-zA-Z0-9.-]+)>?\r\n",
+        "pass": [
+            "to:[email protected]\r\n",
+            "to:\"John Doe\" <[email protected]>\r\n",
+            "to:[email protected]\r\n",
+            "to:[email protected]\r\n",
+            "\r\nto:[email protected]\r\n"
+        ],
+        "fail": [
+            "to:@example.com\r\n",
+            "to:user@\r\n",
+            "from:[email protected]\r\n",
+            "to:[email protected]"
+        ]
     }
 ]

packages/compiler/src/regex.rs

@@ -985,6 +985,11 @@ pub(crate) fn get_regex_and_dfa(
         .map(|regex| regex.regex_def.as_str())
         .collect::<String>();
 
+    // Remove epsilon transitions
+    for state in &mut net_dfa_graph.states {
+        state.transitions.retain(|_, chars| !chars.is_empty());
+    }
+
     Ok(RegexAndDFA {
         regex_pattern: regex_str,
         dfa: net_dfa_graph,
@@ -1033,6 +1038,7 @@ fn create_dfa_graph_from_regex(regex: &str) -> Result<DFAGraph, CompilerError> {
 /// # Returns
 ///
 /// A boolean indicating whether the input string matches the regex pattern.
+#[cfg(test)]
 fn match_string_with_dfa_graph(graph: &DFAGraph, input: &str) -> bool {
     let mut current_state = 0;
 
@@ -1132,10 +1138,12 @@ pub(crate) fn get_max_state(dfa: &DFAGraph) -> usize {
         .unwrap_or_default()
 }
 
+#[cfg(test)]
 mod dfa_test {
-    use crate::regex::{create_dfa_graph_from_regex, match_string_with_dfa_graph};
+    use super::create_dfa_graph_from_regex;
+    use crate::regex::match_string_with_dfa_graph;
     use serde::{Deserialize, Serialize};
-    use std::{env, fs::File, io::BufReader, path::PathBuf};
+    use std::{fs::File, io::BufReader, path::PathBuf};
 
     #[derive(Debug, Deserialize, Serialize)]
     struct RegexTestCase {