pq connection string parsing from other project

pgLabII.PgUtils.Tests/ConnectionStrings/Util/UnitTestTokenizer.cs

@@ -0,0 +1,84 @@
+using pgLabII.PgUtils.ConnectionStrings;
+
+namespace pgLabII.PgUtils.Tests.ConnectionStrings;
+
+internal class UnitTestTokenizer : IPqConnectionStringTokenizer
+{
+    private readonly struct Elem(PqToken result, object? output)
+    {
+        public readonly PqToken Result = result;
+        public readonly object? Output = output;
+    }
+
+    private readonly List<Elem> _tokens = [];
+    private int _position = 0;
+
+
+    public UnitTestTokenizer AddString(string? output)
+    {
+        _tokens.Add(new(PqToken.String, output));
+        return this;
+    }
+
+    public UnitTestTokenizer AddException(Exception? output)
+    {
+        _tokens.Add(new(PqToken.Exception, output));
+        return this;
+    }
+
+    public UnitTestTokenizer AddEquals()
+    {
+        _tokens.Add(new(PqToken.Equals, null));
+        return this;
+    }
+
+    // note we do no whitespace at end tests here
+    public bool Eof => _position >= _tokens.Count;
+
+    public string GetKeyword()
+    {
+        EnsureNotEof();
+        var elem = Consume();
+        if (elem.Result == PqToken.String)
+            return (string)elem.Output!;
+
+        throw new Exception("Unexpected call to GetKeyword");
+    }
+
+
+    public void ConsumeEquals()
+    {
+        EnsureNotEof();
+        var elem = Consume();
+        if (elem.Result == PqToken.Equals)
+            return;
+
+        throw new Exception("Unexpected call to ConsumeEquals");
+    }
+
+    public string GetValue()
+    {
+        EnsureNotEof();
+        var elem = Consume();
+        if (elem.Result == PqToken.String)
+            return (string)elem.Output!;
+
+        throw new Exception("Unexpected call to GetValue");
+    }
+
+    private Elem Consume()
+    {
+        var elem = _tokens[_position++];
+        if (elem.Result == PqToken.Exception)
+        {
+            throw (Exception)elem.Output!;
+        }
+        return elem;
+    }
+
+    private void EnsureNotEof()
+    {
+        if (Eof)
+            throw new Exception("unexpected eof in test, wrong parser call?");
+    }
+}