Fix libpq parsing and refactors/code cleanup

pgLabII.PgUtils.Tests/ConnectionStrings/PqConnectionStringParserTests.cs

@@ -1,4 +1,6 @@
-using pgLabII.PgUtils.ConnectionStrings;
+using FluentResults;
+using pgLabII.PgUtils.ConnectionStrings;
+using pgLabII.PgUtils.Tests.ConnectionStrings.Util;
 
 namespace pgLabII.PgUtils.Tests.ConnectionStrings;
 
@@ -22,20 +24,25 @@ public class PqConnectionStringParserTests
     public void Success()
     {
         var parser = new PqConnectionStringParser(tokenizer);
-        IDictionary<string, string> output = parser.Parse();
+        Result<IDictionary<string, string>> output = parser.Parse();
-
+        ResultAssert.Success(output, v =>
-        Assert.Single(output);
+        {
-        Assert.True(output.TryGetValue(kw, out string? result));
+            Assert.Single(v);
-        Assert.Equal(val, result);
+            Assert.True(v.TryGetValue(kw, out string? result));
+            Assert.Equal(val, result);
+        });
     }
 
     [Fact]
     public void StaticParse()
     {
-        var output = PqConnectionStringParser.Parse("foo=bar");
+        Result<IDictionary<string, string>> output = PqConnectionStringParser.Parse("foo=bar");
-        Assert.Single(output);
+        ResultAssert.Success(output, v =>
-        Assert.True(output.TryGetValue("foo", out string? result));
+        {
-        Assert.Equal("bar", result);
+            Assert.Single(v);
+            Assert.True(v.TryGetValue("foo", out string? result));
+            Assert.Equal("bar", result);
+        });
     }
     // There are few tests here as this is a predictive parser and all error handling is done
     // in the tokenizer

pgLabII.PgUtils/ConnectionStrings/CodecCommon.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using Npgsql;
+
+namespace pgLabII.PgUtils.ConnectionStrings;
+
+/// <summary>
+/// Shared helper utilities for codecs to reduce duplication (SSL mode mapping, host:port parsing/formatting,
+/// URL query parsing, and .NET/libpq quoting helpers).
+/// </summary>
+internal static class CodecCommon
+{
+    // SSL mapping
+    public static SslMode ParseSslModeLoose(string s)
+        => s.Trim().ToLowerInvariant() switch
+        {
+            "disable" => SslMode.Disable,
+            "allow" => SslMode.Allow,
+            "prefer" => SslMode.Prefer,
+            "require" => SslMode.Require,
+            "verify-ca" or "verifyca" => SslMode.VerifyCA,
+            "verify-full" or "verifyfull" => SslMode.VerifyFull,
+            _ => throw new ArgumentException($"Not a valid SSL Mode: {s}")
+        };
+
+    public static string FormatSslModeUrlLike(SslMode mode) => mode switch
+    {
+        SslMode.Disable => "disable",
+        SslMode.Allow => "allow",
+        SslMode.Prefer => "prefer",
+        SslMode.Require => "require",
+        SslMode.VerifyCA => "verify-ca",
+        SslMode.VerifyFull => "verify-full",
+        _ => "prefer"
+    };
+   
+
+    // host:port parsing for plain or [IPv6]:port
+    public static void ParseHostPort(string hostPart, out string host, out ushort? port)
+    {
+        host = hostPart;
+        port = null;
+        if (string.IsNullOrWhiteSpace(hostPart)) 
+            return;
+        
+        if (hostPart[0] == '[')
+        {
+            int end = hostPart.IndexOf(']');
+            if (end > 0)
+            {
+                host = hostPart[1..end];
+                if (end + 1 < hostPart.Length && hostPart[end + 1] == ':')
+                {
+                    string ps = hostPart[(end + 2)..];
+                    if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var p))
+                        port = p;
+                }
+            }
+            return;
+        }
+        int colon = hostPart.LastIndexOf(':');
+        if (colon > 0 && colon < hostPart.Length - 1)
+        {
+            var ps = hostPart.Substring(colon + 1);
+            if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var p))
+            {
+                host = hostPart.Substring(0, colon);
+                port = p;
+            }
+        }
+    }
+
+    public static string FormatHost(HostEndpoint h)
+    {
+        var host = h.Host;
+        if (host.Contains(':') && !host.StartsWith("[")) 
+            host = "[" + host + "]"; // IPv6
+        
+        return h.Port.HasValue ? host + ":" + h.Port.Value.ToString(CultureInfo.InvariantCulture) : host;
+    }
+    
+    public static string[] SplitHosts(string hostList)
+        => hostList.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+    public static Dictionary<string, string> ParseQuery(string query)
+    {
+        var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        if (string.IsNullOrEmpty(query)) return dict;
+        foreach (var kv in query.Split('&', StringSplitOptions.RemoveEmptyEntries))
+        {
+            var parts = kv.Split('=', 2);
+            var key = Uri.UnescapeDataString(parts[0]);
+            var val = parts.Length > 1 ? Uri.UnescapeDataString(parts[1]) : string.Empty;
+            dict[key] = val;
+        }
+        return dict;
+    }
+}

pgLabII.PgUtils/ConnectionStrings/ConnectionDescriptorBuilder.cs

@@ -0,0 +1,36 @@
+using Npgsql;
+
+namespace pgLabII.PgUtils.ConnectionStrings;
+
+public sealed class ConnectionDescriptorBuilder
+{
+    private List<HostEndpoint> Hosts { get; } = [];
+    public string? Database { get; set; }
+    public string? Username { get; set; }
+    public string? Password { get; set; }
+    public SslMode? SslMode { get; set; }
+    public string? ApplicationName { get; set; }
+    public int? TimeoutSeconds { get; set; }
+    public Dictionary<string, string> Properties { get; } = new(StringComparer.OrdinalIgnoreCase);
+
+    public void AddHost(string host, ushort? port)
+    {
+        if (string.IsNullOrWhiteSpace(host)) return;
+        Hosts.Add(new HostEndpoint { Host = host.Trim(), Port = port });
+    }
+
+    public ConnectionDescriptor Build()
+    {
+        return new ConnectionDescriptor
+        {
+            Hosts = Hosts,
+            Database = Database,
+            Username = Username,
+            Password = Password,
+            SslMode = SslMode,
+            ApplicationName = ApplicationName,
+            TimeoutSeconds = TimeoutSeconds,
+            Properties = Properties
+        };
+    }
+}

pgLabII.PgUtils/ConnectionStrings/JdbcCodec.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq;
 using System.Text;
@@ -46,11 +47,11 @@ public sealed class JdbcCodec : IConnectionStringCodec
             var builder = new ConnectionDescriptorBuilder();
 
             // Parse hosts (comma separated)
-            foreach (var part in SplitHosts(authority))
+            foreach (string part in CodecCommon.SplitHosts(authority))
             {
-                if (string.IsNullOrWhiteSpace(part)) continue;
+                CodecCommon.ParseHostPort(part, out var host, out ushort? port);
-                ParseHostPort(part, out var host, out ushort? port);
+                if (!string.IsNullOrEmpty(host)) 
-                if (!string.IsNullOrEmpty(host)) builder.AddHost(host!, port);
+                    builder.AddHost(host!, port);
             }
 
             // Parse database and query
@@ -59,8 +60,8 @@ public sealed class JdbcCodec : IConnectionStringCodec
             if (!string.IsNullOrEmpty(pathAndQuery))
             {
                 int qIdx = pathAndQuery.IndexOf('?');
-                var path = qIdx >= 0 ? pathAndQuery.Substring(0, qIdx) : pathAndQuery;
+                string path = qIdx >= 0 ? pathAndQuery[..qIdx] : pathAndQuery;
-                query = qIdx >= 0 ? pathAndQuery.Substring(qIdx + 1) : string.Empty;
+                query = qIdx >= 0 ? pathAndQuery[(qIdx + 1)..] : string.Empty;
                 if (path.Length > 0)
                 {
                     if (path[0] == '/') path = path.Substring(1);
@@ -70,21 +71,22 @@ public sealed class JdbcCodec : IConnectionStringCodec
             }
             if (!string.IsNullOrEmpty(database)) builder.Database = database;
 
-            var queryDict = ParseQuery(query);
+            var queryDict = CodecCommon.ParseQuery(query);
 
             // Map known properties
-            if (TryFirst(queryDict, out var ssl, "sslmode", "ssl"))
+            if (TryFirst(queryDict, out string? ssl, "sslmode", "ssl"))
-                builder.SslMode = ParseSslMode(ssl);
+                builder.SslMode = CodecCommon.ParseSslModeLoose(ssl);
-            if (TryFirst(queryDict, out var app, "applicationName", "application_name"))
+            if (TryFirst(queryDict, out string? app, "applicationName", "application_name"))
                 builder.ApplicationName = app;
-            if (TryFirst(queryDict, out var tout, "loginTimeout", "connectTimeout", "connect_timeout"))
+            if (TryFirst(queryDict, out string? tout, "loginTimeout", "connectTimeout", "connect_timeout"))
             {
-                if (int.TryParse(tout, NumberStyles.Integer, CultureInfo.InvariantCulture, out var t))
+                if (int.TryParse(tout, NumberStyles.Integer, CultureInfo.InvariantCulture, out int t))
                     builder.TimeoutSeconds = t;
             }
 
             // Preserve extras
-            var mapped = new HashSet<string>(new[] { "sslmode", "ssl", "applicationName", "application_name", "loginTimeout", "connectTimeout", "connect_timeout" }, StringComparer.OrdinalIgnoreCase);
+            var mapped = new HashSet<string>(["sslmode", "ssl", "applicationName", "application_name", "loginTimeout", "connectTimeout", "connect_timeout"
+            ], StringComparer.OrdinalIgnoreCase);
             foreach (var kv in queryDict)
             {
                 if (!mapped.Contains(kv.Key))
@@ -106,7 +108,7 @@ public sealed class JdbcCodec : IConnectionStringCodec
             var sb = new StringBuilder();
             sb.Append("jdbc:postgresql://");
 
-            if (descriptor.Hosts != null && descriptor.Hosts.Count > 0)
+            if (descriptor.Hosts.Count > 0)
             {
                 sb.Append(string.Join(',', descriptor.Hosts.Select(FormatHost)));
             }
@@ -122,7 +124,7 @@ public sealed class JdbcCodec : IConnectionStringCodec
             var qp = new List<(string k, string v)>();
             if (descriptor.SslMode.HasValue)
             {
-                qp.Add(("sslmode", FormatSslMode(descriptor.SslMode.Value)));
+                qp.Add(("sslmode", CodecCommon.FormatSslModeUrlLike(descriptor.SslMode.Value)));
             }
             if (!string.IsNullOrEmpty(descriptor.ApplicationName))
             {
@@ -155,139 +157,19 @@ public sealed class JdbcCodec : IConnectionStringCodec
         }
     }
     
-    private static IEnumerable<string> SplitHosts(string authority)
+    private static string FormatHost(HostEndpoint h) => CodecCommon.FormatHost(h);
-    {
-        return authority.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
-    }
 
-    private static string FormatHost(HostEndpoint h)
+    private static bool TryFirst(
+        Dictionary<string, string> dict,
+        [MaybeNullWhen(false)] out string value,
+        params string[] keys)
     {
-        var host = h.Host;
+        foreach (string k in keys)
-        if (host.Contains(':') && !host.StartsWith("["))
         {
-            // IPv6 literal must be bracketed
+            if (dict.TryGetValue(k, out value)) 
-            host = "[" + host + "]";
+                return true;
-        }
-        return h.Port.HasValue ? host + ":" + h.Port.Value.ToString(CultureInfo.InvariantCulture) : host;
-    }
-
-    private static void ParseHostPort(string hostPart, out string host, out ushort? port)
-    {
-        host = hostPart;
-        port = null;
-        if (string.IsNullOrWhiteSpace(hostPart)) return;
-
-        if (hostPart[0] == '[')
-        {
-            int end = hostPart.IndexOf(']');
-            if (end > 0)
-            {
-                host = hostPart.Substring(1, end - 1);
-                if (end + 1 < hostPart.Length && hostPart[end + 1] == ':')
-                {
-                    var ps = hostPart.Substring(end + 2);
-                    if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var p))
-                        port = p;
-                }
-            }
-            return;
-        }
-        int colon = hostPart.LastIndexOf(':');
-        if (colon > 0 && colon < hostPart.Length - 1)
-        {
-            var ps = hostPart.Substring(colon + 1);
-            if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var p))
-            {
-                host = hostPart.Substring(0, colon);
-                port = p;
-            }
-        }
-    }
-
-    private static Dictionary<string, string> ParseQuery(string query)
-    {
-        var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        if (string.IsNullOrEmpty(query)) return dict;
-        foreach (var kv in query.Split('&', StringSplitOptions.RemoveEmptyEntries))
-        {
-            var parts = kv.Split('=', 2);
-            var key = Uri.UnescapeDataString(parts[0]);
-            var val = parts.Length > 1 ? Uri.UnescapeDataString(parts[1]) : string.Empty;
-            dict[key] = val;
-        }
-        return dict;
-    }
-
-    private static bool TryFirst(Dictionary<string, string> dict, out string value, params string[] keys)
-    {
-        foreach (var k in keys)
-        {
-            if (dict.TryGetValue(k, out value)) return true;
         }
         value = string.Empty;
         return false;
     }
-
-    private static SslMode ParseSslMode(string s)
-    {
-        switch (s.Trim().ToLowerInvariant())
-        {
-            case "disable": return SslMode.Disable;
-            case "allow": return SslMode.Allow;
-            case "prefer": return SslMode.Prefer;
-            case "require": return SslMode.Require;
-            case "verify-ca":
-            case "verifyca": return SslMode.VerifyCA;
-            case "verify-full":
-            case "verifyfull": return SslMode.VerifyFull;
-            default: throw new ArgumentException($"Not a valid SSL Mode: {s}");
-        }
-    }
-
-    private static string FormatSslMode(SslMode mode)
-    {
-        return mode switch
-        {
-            SslMode.Disable => "disable",
-            SslMode.Allow => "allow",
-            SslMode.Prefer => "prefer",
-            SslMode.Require => "require",
-            SslMode.VerifyCA => "verify-ca",
-            SslMode.VerifyFull => "verify-full",
-            _ => "prefer"
-        };
-    }
-
-    private sealed class ConnectionDescriptorBuilder
-    {
-        public List<HostEndpoint> Hosts { get; } = new();
-        public string? Database { get; set; }
-        public string? Username { get; set; }
-        public string? Password { get; set; }
-        public SslMode? SslMode { get; set; }
-        public string? ApplicationName { get; set; }
-        public int? TimeoutSeconds { get; set; }
-        public Dictionary<string, string> Properties { get; } = new(StringComparer.OrdinalIgnoreCase);
-
-        public void AddHost(string host, ushort? port)
-        {
-            if (string.IsNullOrWhiteSpace(host)) return;
-            Hosts.Add(new HostEndpoint { Host = host.Trim(), Port = port });
-        }
-
-        public ConnectionDescriptor Build()
-        {
-            return new ConnectionDescriptor
-            {
-                Hosts = Hosts,
-                Database = Database,
-                Username = Username,
-                Password = Password,
-                SslMode = SslMode,
-                ApplicationName = ApplicationName,
-                TimeoutSeconds = TimeoutSeconds,
-                Properties = Properties
-            };
-        }
-    }
 }

pgLabII.PgUtils/ConnectionStrings/NpgsqlCodec.cs

@@ -1,7 +1,4 @@
-using System;
+using System.Globalization;
-using System.Collections.Generic;
-using System.Globalization;
-using System.Linq;
 using System.Text;
 using FluentResults;
 using Npgsql;
@@ -222,35 +219,18 @@ public sealed class NpgsqlCodec : IConnectionStringCodec
         return false;
     }
 
-    private static SslMode ParseSslMode(string s)
+    private static SslMode ParseSslMode(string s) => CodecCommon.ParseSslModeLoose(s);
-    {
-        switch (s.Trim().ToLowerInvariant())
-        {
-            case "disable": return SslMode.Disable;
-            case "allow": return SslMode.Allow;
-            case "prefer": return SslMode.Prefer;
-            case "require": return SslMode.Require;
-            case "verify-ca":
-            case "verifyca": return SslMode.VerifyCA;
-            case "verify-full":
-            case "verifyfull": return SslMode.VerifyFull;
-            default: throw new ArgumentException($"Not a valid SSL Mode: {s}");
-        }
-    }
 
-    private static string FormatSslMode(SslMode mode)
+    private static string FormatSslMode(SslMode mode) => mode switch
     {
-        return mode switch
+        SslMode.Disable => "Disable",
-        {
+        SslMode.Allow => "Allow",
-            SslMode.Disable => "Disable",
+        SslMode.Prefer => "Prefer",
-            SslMode.Allow => "Allow",
+        SslMode.Require => "Require",
-            SslMode.Prefer => "Prefer",
+        SslMode.VerifyCA => "VerifyCA",
-            SslMode.Require => "Require",
+        SslMode.VerifyFull => "VerifyFull",
-            SslMode.VerifyCA => "VerifyCA",
+        _ => "Prefer"
-            SslMode.VerifyFull => "VerifyFull",
+    };
-            _ => "Prefer"
-        };
-    }
 
     // Npgsql/.NET connection string grammar: semicolon-separated key=value; values with special chars are wrapped in quotes, internal quotes doubled
     private static string FormatPair(string key, string? value)
@@ -343,37 +323,4 @@ public sealed class NpgsqlCodec : IConnectionStringCodec
 
         return dict;
     }
-
-    private sealed class ConnectionDescriptorBuilder
-    {
-        public List<HostEndpoint> Hosts { get; } = new();
-        public string? Database { get; set; }
-        public string? Username { get; set; }
-        public string? Password { get; set; }
-        public SslMode? SslMode { get; set; }
-        public string? ApplicationName { get; set; }
-        public int? TimeoutSeconds { get; set; }
-        public Dictionary<string, string> Properties { get; } = new(StringComparer.OrdinalIgnoreCase);
-
-        public void AddHost(string host, ushort? port)
-        {
-            if (string.IsNullOrWhiteSpace(host)) return;
-            Hosts.Add(new HostEndpoint { Host = host.Trim(), Port = port });
-        }
-
-        public ConnectionDescriptor Build()
-        {
-            return new ConnectionDescriptor
-            {
-                Hosts = Hosts,
-                Database = Database,
-                Username = Username,
-                Password = Password,
-                SslMode = SslMode,
-                ApplicationName = ApplicationName,
-                TimeoutSeconds = TimeoutSeconds,
-                Properties = Properties
-            };
-        }
-    }
 }

pgLabII.PgUtils/ConnectionStrings/PLAN.md

@@ -1,54 +0,0 @@
-# Connection Strings Plan
-
-This document tracks the plan for supporting multiple PostgreSQL connection string formats, converting between them, and mapping to/from a canonical model.
-
-## Current Status (2025-08-31)
-
-Implemented:
-- Abstractions: `ConnStringFormat`, `HostEndpoint`, `ConnectionDescriptor`, `IConnectionStringCodec`, `IConnectionStringService`.
-- Codecs:
-  - `LibpqCodec` (libpq): parse/format; multi-host; `sslmode`, `application_name`, `connect_timeout`; quoting/escaping; preserves extras.
-  - `NpgsqlCodec` (.NET/Npgsql): parse/format; alias recognition; multi-host with single or per-host ports; `SSL Mode`, `Application Name`, `Timeout`; double-quote rules; preserves extras.
-  - `UrlCodec` (postgresql://): parse/format; userinfo, multi-host with per-host ports, IPv6 `[::1]` handling, database path, percent-decoding/encoding, common params mapping, preserves extras.
-- Composite `ConnectionStringService` (detect + convert) composing Libpq, Npgsql, and Url codecs.
-- Mapping helpers to/from `ServerConfiguration` (primary host/port, database, SSL mode) with sensible defaults.
-- Tests:
-  - Unit tests for Libpq, Npgsql, and Url codecs (parse/format/round-trip/edge quoting and percent-encoding).
-  - ConnectionStringService detection/conversion tests.
-  - ServerConfiguration mapping tests.
-
-Not yet implemented:
-- JDBC (jdbc:postgresql://) codec
-
-## Updated Plan
-
-1. Define canonical model and interfaces for connection strings. ✓
-2. Establish normalization strategy for parameter aliases and extra `Properties` handling. ✓
-3. Implement format-specific codecs:
-   - libpq codec (parse/format; multi-host, quoting, sslmode, timeout, extras). ✓
-   - Npgsql codec (parse/format; aliases, multi-host/ports, quoting, ssl mode, timeout, extras). ✓
-   - URL (postgresql://) codec (parse/format; userinfo, host[:port], db, query params, percent-encoding). ✓
-   - JDBC (jdbc:postgresql://) codec (parse/format; hosts, ports, db, properties; URL-like semantics).
-4. Composite conversion service. ✓
-5. Mapping with application model. ✓
-6. Validation and UX:
-   - Validation for malformed inputs & edge cases (mismatched host/port counts, invalid SSL mode, missing db/host, IPv6 bracket handling). ✓
-   - Ensure sensitive fields (password) are masked in logs/preview). ✓
-7. Tests:
-   - Unit tests for URL codec (parse/format/round-trip/percent-encoding). ✓
-   - Tests for composite service detect/convert; mapping functions; cross-format round-trips; edge cases (spaces, quotes, unicode, IPv6, percent-encoding). ✓
-   - Unit tests for JDBC codec.
-8. Documentation:
-   - Keep this plan updated and enrich XML docs on codecs/service including alias mappings and quoting/escaping rules per format. *
-
-## Next Small Step
-
-Implement the JDBC (jdbc:postgresql://) codec with unit tests. Scope:
-- Parse: `jdbc:postgresql://host1[:port1][,hostN[:portN]]/[database]?param=value&...`
-  - Support multiple hosts with optional per-host ports; IPv6 bracket handling.
-  - Recognize common properties (sslmode/SSL, applicationName, loginTimeout/connectTimeout) and preserve unrecognized properties.
-  - Ensure URL-like semantics consistent with UrlCodec percent-decoding/encoding.
-- Format: Build JDBC URL from ConnectionDescriptor; emit multi-hosts and properties from `Properties` not already emitted.
-- Tests: basic parse/format, multi-host with mixed ports, percent-encoding, round-trips; cross-format conversions via ConnectionStringService.
-
-After that, consider minor documentation polish and any gaps in edge-case validation discovered while adding JDBC support.

pgLabII.PgUtils/ConnectionStrings/Pq/LibpqCodec.cs

@@ -1,9 +1,5 @@
-using System;
+using System.Text;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using FluentResults;
-using Npgsql;
 
 namespace pgLabII.PgUtils.ConnectionStrings;
 
@@ -16,14 +12,13 @@ public sealed class LibpqCodec : IConnectionStringCodec
     {
         try
         {
-            // Reject Npgsql-style strings that use ';' separators when forcing libpq
+            Result<IDictionary<string, string>> kv = new PqConnectionStringParser(new PqConnectionStringTokenizer(input)).Parse();
-            if (input.IndexOf(';') >= 0)
+            if (kv.IsFailed)
-                return Result.Fail<ConnectionDescriptor>("Semicolons are not valid separators in libpq connection strings");
+                return kv.ToResult();
-            var kv = new PqConnectionStringParser(new PqConnectionStringTokenizer(input)).Parse();
 
             // libpq keywords are case-insensitive; normalize to lower for lookup
             var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-            foreach (var pair in kv)
+            foreach (var pair in kv.Value)
                 dict[pair.Key] = pair.Value;
 
             var descriptor = new ConnectionDescriptorBuilder();
@@ -31,7 +26,7 @@ public sealed class LibpqCodec : IConnectionStringCodec
             if (dict.TryGetValue("host", out var host))
             {
                 // libpq supports host lists separated by commas
-                var hosts = host.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                string[] hosts = CodecCommon.SplitHosts(host);
                 ushort? portForAll = null;
                 if (dict.TryGetValue("port", out var portStr) && ushort.TryParse(portStr, out var p))
                     portForAll = p;
@@ -40,10 +35,10 @@ public sealed class LibpqCodec : IConnectionStringCodec
                     descriptor.AddHost(h, portForAll);
                 }
             }
-            if (dict.TryGetValue("hostaddr", out var hostaddr) && !string.IsNullOrWhiteSpace(hostaddr))
+            if (dict.TryGetValue("hostaddr", out string? hostaddr) && !string.IsNullOrWhiteSpace(hostaddr))
             {
-                // If hostaddr is provided without host, include as host entries as well
+                // If hostaddr is provided without a host, include as host entries as well
-                var hosts = hostaddr.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                string[] hosts = CodecCommon.SplitHosts(hostaddr);
                 ushort? portForAll = null;
                 if (dict.TryGetValue("port", out var portStr) && ushort.TryParse(portStr, out var p))
                     portForAll = p;
@@ -61,7 +56,7 @@ public sealed class LibpqCodec : IConnectionStringCodec
                 descriptor.Password = pass;
 
             if (dict.TryGetValue("sslmode", out var sslStr))
-                descriptor.SslMode = ParseSslMode(sslStr);
+                descriptor.SslMode = CodecCommon.ParseSslModeLoose(sslStr);
             if (dict.TryGetValue("application_name", out var app))
                 descriptor.ApplicationName = app;
             if (dict.TryGetValue("connect_timeout", out var tout) && int.TryParse(tout, out var seconds))
@@ -93,7 +88,7 @@ public sealed class LibpqCodec : IConnectionStringCodec
             var parts = new List<string>();
 
             // Hosts and port
-            if (descriptor.Hosts != null && descriptor.Hosts.Count > 0)
+            if (descriptor.Hosts.Count > 0)
             {
                 var hostList = string.Join(',', descriptor.Hosts.Select(h => h.Host));
                 parts.Add(FormatPair("host", hostList));
@@ -110,7 +105,7 @@ public sealed class LibpqCodec : IConnectionStringCodec
             if (!string.IsNullOrEmpty(descriptor.Password))
                 parts.Add(FormatPair("password", descriptor.Password));
             if (descriptor.SslMode.HasValue)
-                parts.Add(FormatPair("sslmode", FormatSslMode(descriptor.SslMode.Value)));
+                parts.Add(FormatPair("sslmode", CodecCommon.FormatSslModeUrlLike(descriptor.SslMode.Value)));
             if (!string.IsNullOrEmpty(descriptor.ApplicationName))
                 parts.Add(FormatPair("application_name", descriptor.ApplicationName));
             if (descriptor.TimeoutSeconds.HasValue)
@@ -132,34 +127,6 @@ public sealed class LibpqCodec : IConnectionStringCodec
         }
     }
 
-    private static SslMode ParseSslMode(string s)
-    {
-        return s.Trim().ToLowerInvariant() switch
-        {
-            "disable" => SslMode.Disable,
-            "allow" => SslMode.Allow,
-            "prefer" => SslMode.Prefer,
-            "require" => SslMode.Require,
-            "verify-ca" => SslMode.VerifyCA,
-            "verify-full" => SslMode.VerifyFull,
-            _ => throw new ArgumentException($"Not a valid SSL mode: {s}")
-        };
-    }
-
-    private static string FormatSslMode(SslMode mode)
-    {
-        return mode switch
-        {
-            SslMode.Disable => "disable",
-            SslMode.Allow => "allow",
-            SslMode.Prefer => "prefer",
-            SslMode.Require => "require",
-            SslMode.VerifyCA => "verify-ca",
-            SslMode.VerifyFull => "verify-full",
-            _ => "prefer"
-        };
-    }
-
     private static string FormatPair(string key, string? value)
     {
         value ??= string.Empty;
@@ -170,56 +137,17 @@ public sealed class LibpqCodec : IConnectionStringCodec
 
     private static bool NeedsQuoting(string value)
     {
-        if (value.Length == 0) return true;
+        return value.Any(c => char.IsWhiteSpace(c) || c == '=' || c == '\'' || c == '\\');
-        foreach (var c in value)
-        {
-            if (char.IsWhiteSpace(c) || c == '=' || c == '\'' || c == '\\')
-                return true;
-        }
-        return false;
     }
 
     private static string EscapeValue(string value)
     {
         var sb = new StringBuilder();
-        foreach (var c in value)
+        foreach (char c in value)
         {
             if (c == '\'' || c == '\\') sb.Append('\\');
             sb.Append(c);
         }
         return sb.ToString();
     }
-
-    private sealed class ConnectionDescriptorBuilder
-    {
-        public List<HostEndpoint> Hosts { get; } = new();
-        public string? Database { get; set; }
-        public string? Username { get; set; }
-        public string? Password { get; set; }
-        public SslMode? SslMode { get; set; }
-        public string? ApplicationName { get; set; }
-        public int? TimeoutSeconds { get; set; }
-        public Dictionary<string,string> Properties { get; } = new(StringComparer.OrdinalIgnoreCase);
-
-        public void AddHost(string host, ushort? port)
-        {
-            if (string.IsNullOrWhiteSpace(host)) return;
-            Hosts.Add(new HostEndpoint { Host = host.Trim(), Port = port });
-        }
-
-        public ConnectionDescriptor Build()
-        {
-            return new ConnectionDescriptor
-            {
-                Hosts = Hosts,
-                Database = Database,
-                Username = Username,
-                Password = Password,
-                SslMode = SslMode,
-                ApplicationName = ApplicationName,
-                TimeoutSeconds = TimeoutSeconds,
-                Properties = Properties
-            };
-        }
-    }
 }

pgLabII.PgUtils/ConnectionStrings/Pq/PqConnectionStringParser.cs

@@ -48,7 +48,7 @@ public ref struct PqConnectionStringParser
     //service
     //target_session_attrs
 
-    public static IDictionary<string, string> Parse(string input)
+    public static Result<IDictionary<string, string>> Parse(string input)
     {
         return new PqConnectionStringParser(
             new PqConnectionStringTokenizer(input)
@@ -63,12 +63,16 @@ public ref struct PqConnectionStringParser
         this._tokenizer = tokenizer;
     }
 
-    public IDictionary<string, string> Parse()
+    public Result<IDictionary<string, string>> Parse()
     {
         _result.Clear();
 
         while (!_tokenizer.IsEof)
-            ParsePair();
+        {
+            var result = ParsePair();
+            if (result.IsFailed)
+                return result;
+        }
 
         return _result;
     }

pgLabII.PgUtils/ConnectionStrings/Pq/PqConnectionStringTokenizer.cs

@@ -67,12 +67,6 @@ public class PqConnectionStringTokenizer : IPqConnectionStringTokenizer
     {
         while (position < input.Length && char.IsWhiteSpace(input[position]))
             position++;
-        // If a semicolon is encountered between pairs (which is not valid in libpq),
-        // treat as immediate EOF so parser stops and leaves trailing data unparsed.
-        if (position < input.Length && input[position] == ';')
-        {
-            position = input.Length; // force EOF
-        }
     }
 
     private string UnquotedString(bool forKeyword)

pgLabII.PgUtils/ConnectionStrings/UrlCodec.cs

@@ -1,11 +1,6 @@
-using System;
+using System.Globalization;
-using System.Collections.Generic;
-using System.Globalization;
-using System.Linq;
-using System.Net;
 using System.Text;
 using FluentResults;
-using Npgsql;
 
 namespace pgLabII.PgUtils.ConnectionStrings;
 
@@ -73,13 +68,12 @@ public sealed class UrlCodec : IConnectionStringCodec
                     builder.Password = Uri.UnescapeDataString(up[1]);
             }
 
-            // Parse hosts (may be comma-separated)
+            // Parse hosts (maybe comma-separated)
-            foreach (var hostPart in SplitHosts(authority))
+            foreach (string hostPart in CodecCommon.SplitHosts(authority))
             {
-                if (string.IsNullOrWhiteSpace(hostPart)) continue;
+                CodecCommon.ParseHostPort(hostPart, out string host, out ushort? port);
-                ParseHostPort(hostPart, out var host, out ushort? port);
                 if (!string.IsNullOrEmpty(host))
-                    builder.AddHost(host!, port);
+                    builder.AddHost(host, port);
             }
 
             // Parse path (database) and query
@@ -88,24 +82,25 @@ public sealed class UrlCodec : IConnectionStringCodec
             if (!string.IsNullOrEmpty(pathAndQuery))
             {
                 // pathAndQuery like /db?x=y
-                var qIdx = pathAndQuery.IndexOf('?');
+                int qIdx = pathAndQuery.IndexOf('?');
-                string path = qIdx >= 0 ? pathAndQuery.Substring(0, qIdx) : pathAndQuery;
+                string path = qIdx >= 0 ? pathAndQuery[..qIdx] : pathAndQuery;
-                query = qIdx >= 0 ? pathAndQuery.Substring(qIdx + 1) : string.Empty;
+                query = qIdx >= 0 ? pathAndQuery[(qIdx + 1)..] : string.Empty;
                 if (path.Length > 0)
                 {
                     // strip leading '/'
-                    if (path[0] == '/') path = path.Substring(1);
+                    if (path[0] == '/') 
+                        path = path[1..];
                     if (path.Length > 0)
                         database = Uri.UnescapeDataString(path);
                 }
             }
             if (!string.IsNullOrEmpty(database)) builder.Database = database;
 
-            var queryDict = ParseQuery(query);
+            var queryDict = CodecCommon.ParseQuery(query);
 
             // Map known params
             if (queryDict.TryGetValue("sslmode", out var sslVal))
-                builder.SslMode = ParseSslMode(sslVal);
+                builder.SslMode = CodecCommon.ParseSslModeLoose(sslVal);
             if (queryDict.TryGetValue("application_name", out var app))
                 builder.ApplicationName = app;
             if (queryDict.TryGetValue("connect_timeout", out var tout) && int.TryParse(tout, NumberStyles.Integer, CultureInfo.InvariantCulture, out var ts))
@@ -146,7 +141,7 @@ public sealed class UrlCodec : IConnectionStringCodec
             }
 
             // hosts
-            if (descriptor.Hosts != null && descriptor.Hosts.Count > 0)
+            if (descriptor.Hosts.Count > 0)
             {
                 var hostParts = new List<string>(descriptor.Hosts.Count);
                 foreach (var h in descriptor.Hosts)
@@ -170,7 +165,7 @@ public sealed class UrlCodec : IConnectionStringCodec
             // query
             var queryPairs = new List<string>();
             if (descriptor.SslMode.HasValue)
-                queryPairs.Add("sslmode=" + Uri.EscapeDataString(FormatSslMode(descriptor.SslMode.Value)));
+                queryPairs.Add("sslmode=" + Uri.EscapeDataString(CodecCommon.FormatSslModeUrlLike(descriptor.SslMode.Value)));
             if (!string.IsNullOrEmpty(descriptor.ApplicationName))
                 queryPairs.Add("application_name=" + Uri.EscapeDataString(descriptor.ApplicationName));
             if (descriptor.TimeoutSeconds.HasValue)
@@ -202,153 +197,4 @@ public sealed class UrlCodec : IConnectionStringCodec
         => key.Equals("sslmode", StringComparison.OrdinalIgnoreCase)
            || key.Equals("application_name", StringComparison.OrdinalIgnoreCase)
            || key.Equals("connect_timeout", StringComparison.OrdinalIgnoreCase);
-
-    private static IEnumerable<string> SplitHosts(string authority)
-    {
-        // authority may contain comma-separated hosts, each may be IPv6 [..] with optional :port
-        // We split on commas that are not inside brackets
-        var parts = new List<string>();
-        int depth = 0;
-        int start = 0;
-        for (int i = 0; i < authority.Length; i++)
-        {
-            char c = authority[i];
-            if (c == '[') depth++;
-            else if (c == ']') depth = Math.Max(0, depth - 1);
-            else if (c == ',' && depth == 0)
-            {
-                parts.Add(authority.Substring(start, i - start));
-                start = i + 1;
-            }
-        }
-        // last
-        if (start <= authority.Length)
-            parts.Add(authority.Substring(start));
-        return parts.Select(p => p.Trim()).Where(p => p.Length > 0);
-    }
-
-    private static void ParseHostPort(string hostPart, out string host, out ushort? port)
-    {
-        host = string.Empty; port = null;
-        if (string.IsNullOrWhiteSpace(hostPart)) return;
-
-        if (hostPart[0] == '[')
-        {
-            // IPv6 literal [....]:port?
-            int end = hostPart.IndexOf(']');
-            if (end < 0)
-            {
-                host = hostPart; // let it pass raw
-                return;
-            }
-            var h = hostPart.Substring(1, end - 1);
-            host = h;
-            if (end + 1 < hostPart.Length && hostPart[end + 1] == ':')
-            {
-                var ps = hostPart.Substring(end + 2);
-                if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var up))
-                    port = up;
-            }
-            return;
-        }
-        // non-IPv6, split last ':' as port if numeric
-        int colon = hostPart.LastIndexOf(':');
-        if (colon > 0 && colon < hostPart.Length - 1)
-        {
-            var ps = hostPart.Substring(colon + 1);
-            if (ushort.TryParse(ps, NumberStyles.Integer, CultureInfo.InvariantCulture, out var up))
-            {
-                port = up;
-                host = hostPart.Substring(0, colon);
-                return;
-            }
-        }
-        host = hostPart;
-    }
-
-    private static SslMode ParseSslMode(string s)
-    {
-        switch (s.Trim().ToLowerInvariant())
-        {
-            case "disable": return SslMode.Disable;
-            case "allow": return SslMode.Allow;
-            case "prefer": return SslMode.Prefer;
-            case "require": return SslMode.Require;
-            case "verify-ca":
-            case "verifyca": return SslMode.VerifyCA;
-            case "verify-full":
-            case "verifyfull": return SslMode.VerifyFull;
-            default: throw new ArgumentException($"Not a valid sslmode: {s}");
-        }
-    }
-
-    private static string FormatSslMode(SslMode mode)
-    {
-        return mode switch
-        {
-            SslMode.Disable => "disable",
-            SslMode.Allow => "allow",
-            SslMode.Prefer => "prefer",
-            SslMode.Require => "require",
-            SslMode.VerifyCA => "verify-ca",
-            SslMode.VerifyFull => "verify-full",
-            _ => "prefer"
-        };
-    }
-
-    private sealed class ConnectionDescriptorBuilder
-    {
-        public List<HostEndpoint> Hosts { get; } = new();
-        public string? Database { get; set; }
-        public string? Username { get; set; }
-        public string? Password { get; set; }
-        public SslMode? SslMode { get; set; }
-        public string? ApplicationName { get; set; }
-        public int? TimeoutSeconds { get; set; }
-        public Dictionary<string, string> Properties { get; } = new(StringComparer.OrdinalIgnoreCase);
-
-        public void AddHost(string host, ushort? port)
-        {
-            if (string.IsNullOrWhiteSpace(host)) return;
-            Hosts.Add(new HostEndpoint { Host = host.Trim(), Port = port });
-        }
-
-        public ConnectionDescriptor Build()
-        {
-            return new ConnectionDescriptor
-            {
-                Hosts = Hosts,
-                Database = Database,
-                Username = Username,
-                Password = Password,
-                SslMode = SslMode,
-                ApplicationName = ApplicationName,
-                TimeoutSeconds = TimeoutSeconds,
-                Properties = Properties
-            };
-        }
-    }
-
-    private static Dictionary<string, string> ParseQuery(string query)
-    {
-        var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        if (string.IsNullOrEmpty(query)) return dict;
-        var pairs = query.Split('&', StringSplitOptions.RemoveEmptyEntries);
-        foreach (var pair in pairs)
-        {
-            var idx = pair.IndexOf('=');
-            if (idx < 0)
-            {
-                var k = Uri.UnescapeDataString(pair);
-                dict[k] = string.Empty;
-            }
-            else
-            {
-                var k = Uri.UnescapeDataString(pair.Substring(0, idx));
-                var v = Uri.UnescapeDataString(pair.Substring(idx + 1));
-                dict[k] = v;
-            }
-        }
-        return dict;
-    }
 }

pgLabII.Tests/Views/EditServerConfigurationWindowTests.cs

@@ -1,9 +1,5 @@
 using System;
-using System.Linq;
-using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Headless.XUnit;
-using Avalonia.Threading;
 using pgLabII.Model;
 using pgLabII.ViewModels;
 using pgLabII.Views;
@@ -52,10 +48,10 @@ public class EditServerConfigurationWindowTests
     {
         var vm = new EditServerConfigurationViewModel(new ServerConfiguration());
 
-        // A semicolon-separated string that could be auto-detected as Npgsql
+        // Use a string with quoted values that libpq would struggle with due to incorrect quoting
-        vm.InputConnectionString = "Host=server;Username=bob;Password=secret;Database=db1;SSL Mode=Require";
+        vm.InputConnectionString = "Host=\"server with spaces\";Username=\"bob\";Password=\"secret\";Database=\"db1\"";
 
-        // Force interpret as libpq should fail to parse (libpq uses spaces) and keep defaults
+        // Force interpret as libpq should fail to parse (libpq expects single quotes, not double quotes for quoting)
         vm.ForcedFormat = EditServerConfigurationViewModel.ForcedFormatOption.Libpq;
         vm.ParseConnectionStringCommand.Execute().Subscribe();
 
@@ -65,7 +61,7 @@ public class EditServerConfigurationWindowTests
         // Now set to Auto and parse again -> should detect Npgsql and parse
         vm.ForcedFormat = EditServerConfigurationViewModel.ForcedFormatOption.Auto;
         vm.ParseConnectionStringCommand.Execute().Subscribe();
-        Assert.Equal("server", vm.Configuration.Host);
+        Assert.Equal("server with spaces", vm.Configuration.Host);
         Assert.Equal("db1", vm.Configuration.InitialDatabase);
         Assert.Equal("bob", vm.Configuration.User.Name);
     }

pgLabII.sln.DotSettings

@@ -0,0 +1,4 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=hostaddr/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=libpq/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=sslmode/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>