Add validation for hiding all the profiles (#2800)

fixes #2794

src/cascadia/LocalTests_TerminalApp/SettingsTests.cpp

@@ -47,6 +47,7 @@ namespace TerminalAppLocalTests
         TEST_METHOD(TestReorderingWithoutGuid);
         TEST_METHOD(TestLayeringNameOnlyProfiles);
         TEST_METHOD(TestExplodingNameOnlyProfiles);
+        TEST_METHOD(TestHideAllProfiles);
 
         TEST_CLASS_SETUP(ClassSetup)
         {
@@ -1125,4 +1126,69 @@ namespace TerminalAppLocalTests
         VERIFY_ARE_EQUAL(L"Windows PowerShell", settings._profiles.at(3)._name);
         VERIFY_ARE_EQUAL(L"cmd", settings._profiles.at(4)._name);
     }
+
+    void SettingsTests::TestHideAllProfiles()
+    {
+        const std::string settingsWithProfiles{ R"(
+        {
+            "profiles": [
+                {
+                    "name" : "profile0",
+                    "hidden": false
+                },
+                {
+                    "name" : "profile1",
+                    "hidden": true
+                }
+            ]
+        })" };
+
+        const std::string settingsWithoutProfiles{ R"(
+        {
+            "profiles": [
+                {
+                    "name" : "profile0",
+                    "hidden": true
+                },
+                {
+                    "name" : "profile1",
+                    "hidden": true
+                }
+            ]
+        })" };
+
+        VerifyParseSucceeded(settingsWithProfiles);
+        VerifyParseSucceeded(settingsWithoutProfiles);
+
+        {
+            // Case 1: Good settings
+            CascadiaSettings settings;
+            settings._ParseJsonString(settingsWithProfiles, false);
+            settings.LayerJson(settings._userSettings);
+
+            settings._RemoveHiddenProfiles();
+            Log::Comment(NoThrowString().Format(
+                L"settingsWithProfiles successfully parsed and validated"));
+            VERIFY_ARE_EQUAL(1u, settings._profiles.size());
+        }
+        {
+            // Case 2: Bad settings
+
+            CascadiaSettings settings;
+            settings._ParseJsonString(settingsWithoutProfiles, false);
+            settings.LayerJson(settings._userSettings);
+
+            bool caughtExpectedException = false;
+            try
+            {
+                settings._RemoveHiddenProfiles();
+            }
+            catch (const ::TerminalApp::SettingsException& ex)
+            {
+                VERIFY_IS_TRUE(ex.Error() == ::TerminalApp::SettingsLoadErrors::AllProfilesHidden);
+                caughtExpectedException = true;
+            }
+            VERIFY_IS_TRUE(caughtExpectedException);
+        }
+    }
 }

src/cascadia/TerminalApp/App.cpp

@@ -30,8 +30,9 @@ static const std::array<std::wstring_view, 2> settingsLoadWarningsLabels {
    L"MissingDefaultProfileText",
    L"DuplicateProfileText"
 };
-static const std::array<std::wstring_view, 1> settingsLoadErrorsLabels {
-    L"NoProfilesText"
+static const std::array<std::wstring_view, 2> settingsLoadErrorsLabels {
+    L"NoProfilesText",
+    L"AllProfilesHiddenText"
 };
 // clang-format on
 

src/cascadia/TerminalApp/CascadiaSettings.cpp

@@ -355,4 +355,14 @@ void CascadiaSettings::_RemoveHiddenProfiles()
                                    _profiles.end(),
                                    [](auto&& profile) { return profile.IsHidden(); }),
                     _profiles.end());
+
+    // Ensure that we still have some profiles here. If we don't, then throw an
+    // exception, so the app can use the defaults.
+    const bool hasProfiles = !_profiles.empty();
+    if (!hasProfiles)
+    {
+        // Throw an exception. This is an invalid state, and we want the app to
+        // be able to gracefully use the default settings.
+        throw ::TerminalApp::SettingsException(::TerminalApp::SettingsLoadErrors::AllProfilesHidden);
+    }
 }

src/cascadia/TerminalApp/Resources/en-US/Resources.resw

@@ -131,6 +131,10 @@
   </data>
   <data name="NoProfilesText" xml:space="preserve">
     <value>No profiles were found in your settings.
+</value>
+  </data>
+  <data name="AllProfilesHiddenText" xml:space="preserve">
+    <value>All profiles were hidden in your settings. You must have at least one non-hidden profile.
 </value>
   </data>
   <data name="ReloadJsonParseErrorText" xml:space="preserve">

src/cascadia/TerminalApp/TerminalWarnings.h

@@ -29,7 +29,8 @@ namespace TerminalApp
     // that we could not recover from.
     enum class SettingsLoadErrors : uint32_t
     {
-        NoProfiles = 0
+        NoProfiles = 0,
+        AllProfilesHidden = 1
     };
 
     // This is a helper class to wrap up a SettingsLoadErrors into a proper