optimize parser

nager · Dec 9, 2024 · cc21fdc · cc21fdc
1 parent 73e1567
commit cc21fdc
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Showing 4 changed files with 79 additions and 11 deletions.
diff --git a/src/Nager.EmailAuthentication.UnitTest/DmarcRecordParserTest.cs b/src/Nager.EmailAuthentication.UnitTest/DmarcRecordParserTest.cs
@@ -6,7 +6,7 @@ public sealed class DmarcRecordParserTest
         [TestMethod]
         public void TryParse_InvalidDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.IsNull(unrecognizedParts);
@@ -15,7 +15,7 @@ public void TryParse_InvalidDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_InvalidDmarcString2_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.IsNull(unrecognizedParts);
@@ -24,7 +24,7 @@ public void TryParse_InvalidDmarcString2_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_InvalidDmarcString3_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=Test", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=Test", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.AreEqual("Test", dmarcDataFragment.DomainPolicy);
@@ -34,7 +34,7 @@ public void TryParse_InvalidDmarcString3_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_InvalidDmarcString4_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=Test;", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=Test;", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.AreEqual("Test", dmarcDataFragment.DomainPolicy);
@@ -44,7 +44,7 @@ public void TryParse_InvalidDmarcString4_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_ValidDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=reject;", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=reject;", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.AreEqual("reject", dmarcDataFragment.DomainPolicy);
@@ -54,7 +54,7 @@ public void TryParse_ValidDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_ValidDmarcString2_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=reject; sp=none;", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("v=DMARC1; p=reject; sp=none;", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.AreEqual("reject", dmarcDataFragment.DomainPolicy);
@@ -65,7 +65,7 @@ public void TryParse_ValidDmarcString2_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_CorruptDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse("verification=123456789", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse("verification=123456789", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dmarcDataFragment);
             Assert.IsNotNull(unrecognizedParts);
@@ -75,7 +75,7 @@ public void TryParse_CorruptDmarcString1_ReturnsTrueAndPopulatesDmarcRecord()
         [TestMethod]
         public void TryParse_CorruptDmarcString2_ReturnsTrueAndPopulatesDmarcRecord()
         {
-            var isSuccessful = DmarcRecordParser.TryParse(" ", out var dmarcDataFragment, out var unrecognizedParts);
+            var isSuccessful = DmarcRecordParser.TryParse(" ", out var dmarcDataFragment, out var unrecognizedParts, out var parseErrors);
             Assert.IsFalse(isSuccessful);
             Assert.IsNull(dmarcDataFragment);
             Assert.IsNull(unrecognizedParts);

diff --git a/src/Nager.EmailAuthentication/DmarcRecordParser.cs b/src/Nager.EmailAuthentication/DmarcRecordParser.cs
@@ -17,7 +17,7 @@ public static bool TryParse(
             string dmarcRaw,
             out DmarcDataFragment? dmarcDataFragment)
         {
-            return TryParse(dmarcRaw, out dmarcDataFragment, out _);
+            return TryParse(dmarcRaw, out dmarcDataFragment, out _, out _);
         }
 
         /// <summary>
@@ -26,20 +26,34 @@ public static bool TryParse(
         /// <param name="dmarcRaw">The raw DMARC string to parse.</param>
         /// <param name="dmarcDataFragment">The parsed DMARC record, if successful.</param>
         /// <param name="unrecognizedParts">A list of unrecognized parts in the DMARC string, if any.</param>
+        /// <param name="parseErrors">A list of errors in the DMARC string, if any.</param>
         /// <returns><see langword="true"/> if parsing is successful; otherwise <see langword="false"/>.</returns>
         public static bool TryParse(
             string dmarcRaw,
             out DmarcDataFragment? dmarcDataFragment,
-            out string[]? unrecognizedParts)
+            out string[]? unrecognizedParts,
+            out ParseError[]? parseErrors)
         {
             unrecognizedParts = null;
+            parseErrors = null;
+
+            var errors = new List<ParseError>();
 
             if (string.IsNullOrWhiteSpace(dmarcRaw))
             {
                 dmarcDataFragment = null;
                 return false;
             }
 
+            if (dmarcRaw.StartsWith("v=DMARC1", StringComparison.OrdinalIgnoreCase))
+            {
+                errors.Add(new ParseError
+                {
+                    ErrorMessage = "DMARC record is invalid: it must start with 'v=DMARC1'.",
+                    Severity = ErrorSeverity.Critical
+                });
+            }
+
             var keyValueParser = new KeyValueParser.MemoryEfficientKeyValueParser(';', '=');
             if (!keyValueParser.TryParse(dmarcRaw, out var parseResult))
             {
@@ -53,6 +67,19 @@ public static bool TryParse(
                 return false;
             }
 
+            var duplicateConfigurations = parseResult.KeyValues
+                .GroupBy(o => o.Key)
+                .Where(g => g.Count() > 1);
+
+            foreach (var duplicate in duplicateConfigurations)
+            {
+                errors.Add(new ParseError
+                {
+                    ErrorMessage = $"Duplicate configuration detected for key: '{duplicate.Key}'.",
+                    Severity = ErrorSeverity.Warning
+                });
+            }
+
             var dataFragment = new DmarcDataFragment();
 
             var unrecognizedHandlers = new List<string>();
@@ -94,7 +121,7 @@ public static bool TryParse(
             }
 
             unrecognizedParts = unrecognizedHandlers.Count == 0 ? null : [.. unrecognizedHandlers];
-
+            parseErrors = errors.Count == 0 ? null : [.. errors];
             dmarcDataFragment = dataFragment;
 
             return true;

diff --git a/src/Nager.EmailAuthentication/Models/ErrorSeverity.cs b/src/Nager.EmailAuthentication/Models/ErrorSeverity.cs
@@ -0,0 +1,23 @@
+namespace Nager.EmailAuthentication.Models
+{
+    /// <summary>
+    /// Error Severity
+    /// </summary>
+    public enum ErrorSeverity
+    {
+        /// <summary>
+        /// Minor issues or informational messages
+        /// </summary>
+        Info,
+
+        /// <summary>
+        /// Potential issues that don't invalidate the DMARC string
+        /// </summary>
+        Warning,
+
+        /// <summary>
+        /// Severe issues that invalidate the DMARC string
+        /// </summary>
+        Critical
+    }
+}
diff --git a/src/Nager.EmailAuthentication/Models/ParseError.cs b/src/Nager.EmailAuthentication/Models/ParseError.cs
@@ -0,0 +1,18 @@
+namespace Nager.EmailAuthentication.Models
+{
+    /// <summary>
+    /// Parse Error
+    /// </summary>
+    public class ParseError
+    {
+        /// <summary>
+        /// Description of the error
+        /// </summary>
+        public required string ErrorMessage { get; set; }
+
+        /// <summary>
+        ///  Severity of the error
+        /// </summary>
+        public ErrorSeverity Severity { get; set; }
+    }
+}