Bugfix Issue #1705 (MAUI: 184): Allow null handling for BaseConverterOneWay<TFrom, TTo> (#1733)

* Fix typo ArgumenException for unit tests

* Add AllowsNullOrDefault handling for BaseConverterOneWay
Fix summary xml doc for ConvertBack of BaseConverterOneWay

* Add BaseConverterOneWay_Tests for new AllowsNullOrDefault

* Implement recommended changes
- Rename test converter to MockConverterOneWay
- Change ArgumentException to ArgumentNullException in BaseConverterOneWay<TFrom, TTo> when disallowing nulls
- Simplify unit test data generation and execution

* Update null check in BaseConverterOneWay<TFrom, TTo>

* Implement recommended changes

- Change check order back to original in BaseConverterOneWay<TFrom, TTo>
- Fix missing first paramName argument for ArgumentNullException in BaseConverterOneWay<TFrom, TTo>
- Refactor BaseConverterOneWay_Tests

* Rename property AllowsNullOrDefault to AllowsNull of BaseConverterOneWay<TFrom, TTo>

* Update IsNullOrEmptyConverter to inherit from BaseConverterOneWay<TFrom, TTo>

* Migrated more converters to base

* Revert compare converter changes

* Fixed unit tests and code review tidy up

* Switch to separate nullable converter base class

* Add null support to BaseConverter

NullableBaseConverter now completes symmetry with NullableBaseConverterOneWay.

Migrate converters to use NullableBaseConverter where possible.

Migrate tests to new approach.

* Remove Null-Forgiving Operator

* Rename converters to start with Base

* Code review improvement

* Add global.json

Ensures .NET 6.0 is the minimum version in use

* `dotnet format`

* Move global.json to root folder

* `dotnet format`

Co-authored-by: Pascal Ried <[email protected]>
Co-authored-by: Shaun Lawrence <[email protected]>
Co-authored-by: Pedro Jesus <[email protected]>
Co-authored-by: Brandon Minnick <[email protected]>

Author: 5 people

Directory.Build.props

@@ -2,7 +2,7 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
   <PropertyGroup Condition="'$(MSBuildProjectExtension)' == '.csproj'">
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>latest</LangVersion>
     <Nullable>enable</Nullable>
     <WarningsAsErrors>nullable</WarningsAsErrors>
   </PropertyGroup>

global.json

@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "6.0.*",
+    "rollForward": "latestMajor"
+  }
+}