Added a free address choice to the Read Web Page tool (#997)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Tools/ToolCalling/ToolSettingsValueParserTests.cs

@@ -0,0 +1,61 @@
+using AIStudio.Tools.ToolCallingSystem;
+
+namespace AIStudio.Tests.Tools.ToolCalling;
+
+/// <summary>
+/// Checks the shared check of a stored choice against the option source it was picked from.
+/// </summary>
+/// <remarks>
+/// A stored value can predate the list it was picked from, or come from an organization's
+/// configuration with a typo in it. Every tool with a choice relies on this check to report such
+/// a value instead of acting on it, so it is tested here once rather than through each tool.
+/// </remarks>
+[TestFixture]
+public sealed class ToolSettingsValueParserTests
+{
+    private const string KEY = "defaultSafeSearch";
+
+    private const string ERROR_FORMAT = "The setting '{0}' holds '{1}'.";
+
+    [TestCase(null)]
+    [TestCase("")]
+    [TestCase("   ")]
+    public void AnEmptyValuePasses(string? value)
+    {
+        var settingsValues = value is null ? new Dictionary<string, string>() : new Dictionary<string, string> { [KEY] = value };
+        var isValid = ToolSettingsValueParser.TryValidateOptionValue(settingsValues, KEY, ToolSettingsOptionSources.SAFE_SEARCH, ERROR_FORMAT, out var error);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(isValid, Is.True, "Whether a field may stay empty is for the schema's required list to decide, not for this check.");
+            Assert.That(error, Is.Empty);
+        });
+    }
+
+    [Test]
+    public void AnOfferedValuePasses()
+    {
+        var settingsValues = new Dictionary<string, string> { [KEY] = nameof(SafeSearchPolicy.MODERATE) };
+        var isValid = ToolSettingsValueParser.TryValidateOptionValue(settingsValues, KEY, ToolSettingsOptionSources.SAFE_SEARCH, ERROR_FORMAT, out var error);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(isValid, Is.True);
+            Assert.That(error, Is.Empty);
+        });
+    }
+
+    [TestCase("moderate")]
+    [TestCase("MEDIUM")]
+    public void AValueNotOfferedIsReportedWithKeyAndValue(string value)
+    {
+        var settingsValues = new Dictionary<string, string> { [KEY] = value };
+        var isValid = ToolSettingsValueParser.TryValidateOptionValue(settingsValues, KEY, ToolSettingsOptionSources.SAFE_SEARCH, ERROR_FORMAT, out var error);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(isValid, Is.False, "The stored value is compared exactly, the way the option source offers it.");
+            Assert.That(error, Is.EqualTo($"The setting '{KEY}' holds '{value}'."), "The message has to name the field and the value, or nobody can find what to correct.");
+        });
+    }
+}