Update to .NET 6 SDK to build and netcoreapp3.1 for test

This requires a few nullable-reference-type overrides in tests where
we're absolutely confident they won't be null (and if we're wrong,
an NRE is fine to break the test).

Signed-off-by: Jon Skeet <[email protected]>

Author: jskeet

.github/workflows/build.yml

@@ -17,22 +17,17 @@ jobs:
     - name: Check out our repo
       uses: actions/checkout@v2
 
-    # We need the .NET Core 2.1 and .NET Core 3.1 runtimes for testing
-    - name: Setup .NET Core 2.1
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 2.1.x
-
+    # We need the .NET Core 3.1 runtime for testing
     - name: Setup .NET Core 3.1
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: 3.1.x
 
-    # Build with .NET Core 5.0 SDK
-    - name: Setup .NET Core 5.0
+    # Build with .NET 6.0 SDK
+    - name: Setup .NET 6.0
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 6.0.x
 
     - name: Build
       run: |

.github/workflows/nuget.yml

@@ -15,22 +15,17 @@ jobs:
     - name: Check out our repo
       uses: actions/checkout@v2
 
-    # We need the .NET Core 2.1 and .NET Core 3.1 runtimes for testing
-    - name: Setup .NET Core 2.1
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 2.1.x
-
+    # We need the .NET Core 3.1 runtime for testing
     - name: Setup .NET Core 3.1
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: 3.1.x
 
-    # Build with .NET Core 5.0 SDK
-    - name: Setup .NET Core 5.0
+    # Build with .NET 6.0 SDK
+    - name: Setup .NET 6.0
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 6.0.x
 
     - name: Build
       run: |

samples/CloudNative.CloudEvents.AspNetCoreSample/CloudNative.CloudEvents.AspNetCoreSample.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;net50</TargetFrameworks>
+    <TargetFrameworks>netcoreapp3.1;net6.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

samples/HttpSend/HttpSend.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

test/CloudNative.CloudEvents.UnitTests/CloudEventAttributeTest.cs

@@ -114,7 +114,7 @@ public void Validate_WithValidator_InvalidValue()
             var exception = Assert.Throws<ArgumentException>(() => attr.Validate(-5));
             Assert.Contains("Custom validation message", exception.Message);
             Assert.IsType<Exception>(exception.InnerException);
-            Assert.Equal("Custom validation message", exception.InnerException.Message);
+            Assert.Equal("Custom validation message", exception.InnerException!.Message);
         }
 
         [Fact]

test/CloudNative.CloudEvents.UnitTests/CloudEventAttributeTypeTest.cs

@@ -43,8 +43,8 @@ public void OrdinalTypeNameMatchesPropertyName()
                 .Where(prop => prop.PropertyType == typeof(CloudEventAttributeType));
             foreach (var property in properties)
             {
-                var type = (CloudEventAttributeType) property.GetValue(null);
-                Assert.Equal(property.Name, type.Ordinal.ToString());
+                var type = (CloudEventAttributeType) property.GetValue(null)!;
+                Assert.Equal(property.Name, type!.Ordinal.ToString());
             }
         }
 

test/CloudNative.CloudEvents.UnitTests/CloudEventTest.cs

@@ -66,7 +66,7 @@ public void Invalid_ContentType_Throws()
         {
             var cloudEvent = new CloudEvent();
             var exception = Assert.Throws<ArgumentException>(() => cloudEvent.DataContentType = "text/html; charset:");
-            Assert.StartsWith(Strings.ErrorContentTypeIsNotRFC2046, exception.InnerException.Message);
+            Assert.StartsWith(Strings.ErrorContentTypeIsNotRFC2046, exception.InnerException!.Message);
         }
 
         [Fact]

test/CloudNative.CloudEvents.UnitTests/CloudNative.CloudEvents.UnitTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
   </PropertyGroup>

test/CloudNative.CloudEvents.UnitTests/SystemTextJson/JsonEventFormatterTest.cs

@@ -981,7 +981,7 @@ private static IReadOnlyList<CloudEvent> DecodeBatchModeMessage(Newtonsoft.Json.
         private class YearMonthDayConverter : JsonConverter<DateTime>
         {
             public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) =>
-                DateTime.ParseExact(reader.GetString(), "yyyy-MM-dd", CultureInfo.InvariantCulture);
+                DateTime.ParseExact(reader.GetString()!, "yyyy-MM-dd", CultureInfo.InvariantCulture);
 
             public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options) =>
                 writer.WriteStringValue(value.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture));