C#: Enable nullability for Autobuild tests project.

Author: calumgrant

csharp/autobuilder/Semmle.Autobuild.Tests/BuildScripts.cs

@@ -44,7 +44,7 @@ bool IBuildActions.FileExists(string file)
         public IDictionary<string, string> RunProcessOut = new Dictionary<string, string>();
         public IDictionary<string, string> RunProcessWorkingDirectory = new Dictionary<string, string>();
 
-        int IBuildActions.RunProcess(string cmd, string args, string workingDirectory, IDictionary<string, string> env, out IList<string> stdOut)
+        int IBuildActions.RunProcess(string cmd, string args, string? workingDirectory, IDictionary<string, string>? env, out IList<string> stdOut)
         {
             var pattern = cmd + " " + args;
             RunProcessIn.Add(pattern);
@@ -60,7 +60,7 @@ int IBuildActions.RunProcess(string cmd, string args, string workingDirectory, I
             throw new ArgumentException("Missing RunProcess " + pattern);
         }
 
-        int IBuildActions.RunProcess(string cmd, string args, string workingDirectory, IDictionary<string, string> env)
+        int IBuildActions.RunProcess(string cmd, string args, string? workingDirectory, IDictionary<string, string>? env)
         {
             var pattern = cmd + " " + args;
             RunProcessIn.Add(pattern);
@@ -90,16 +90,16 @@ bool IBuildActions.DirectoryExists(string dir)
             throw new ArgumentException("Missing DirectoryExists " + dir);
         }
 
-        public IDictionary<string, string> GetEnvironmentVariable = new Dictionary<string, string>();
+        public IDictionary<string, string?> GetEnvironmentVariable = new Dictionary<string, string?>();
 
-        string IBuildActions.GetEnvironmentVariable(string name)
+        string? IBuildActions.GetEnvironmentVariable(string name)
         {
             if (GetEnvironmentVariable.TryGetValue(name, out var ret))
                 return ret;
             throw new ArgumentException("Missing GetEnvironmentVariable " + name);
         }
 
-        public string GetCurrentDirectory;
+        public string GetCurrentDirectory = "";
 
         string IBuildActions.GetCurrentDirectory()
         {
@@ -334,10 +334,10 @@ public void TestTry()
         }
 
         Autobuilder CreateAutoBuilder(string lgtmLanguage, bool isWindows,
-            string buildless = null, string solution = null, string buildCommand = null, string ignoreErrors = null,
-            string msBuildArguments = null, string msBuildPlatform = null, string msBuildConfiguration = null, string msBuildTarget = null,
-            string dotnetArguments = null, string dotnetVersion = null, string vsToolsVersion = null,
-            string nugetRestore = null, string allSolutions = null,
+            string? buildless = null, string? solution = null, string? buildCommand = null, string? ignoreErrors = null,
+            string? msBuildArguments = null, string? msBuildPlatform = null, string? msBuildConfiguration = null, string? msBuildTarget = null,
+            string? dotnetArguments = null, string? dotnetVersion = null, string? vsToolsVersion = null,
+            string? nugetRestore = null, string? allSolutions = null,
             string cwd = @"C:\Project")
         {
             Actions.GetEnvironmentVariable["CODEQL_AUTOBUILDER_CSHARP_NO_INDEXING"] = "false";

csharp/autobuilder/Semmle.Autobuild.Tests/Semmle.Autobuild.Tests.csproj

@@ -5,6 +5,7 @@
     <TargetFramework>netcoreapp3.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <RuntimeIdentifiers>win-x64;linux-x64;osx-x64</RuntimeIdentifiers>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

csharp/autobuilder/Semmle.Autobuild/BuildScript.cs

@@ -61,7 +61,7 @@ class BuildCommand : BuildScript
             /// <param name="silent">Whether this command should run silently.</param>
             /// <param name="workingDirectory">The working directory (<code>null</code> for current directory).</param>
             /// <param name="environment">Additional environment variables.</param>
-            public BuildCommand(string exe, string argumentsOpt, bool silent, string? workingDirectory = null, IDictionary<string, string>? environment = null)
+            public BuildCommand(string exe, string? argumentsOpt, bool silent, string? workingDirectory = null, IDictionary<string, string>? environment = null)
             {
                 this.exe = exe;
                 this.arguments = argumentsOpt ?? "";
@@ -183,7 +183,7 @@ public override int Run(IBuildActions actions, Action<string, bool> startCallbac
         /// <param name="silent">Whether the executable should run silently.</param>
         /// <param name="workingDirectory">The working directory (<code>null</code> for current directory).</param>
         /// <param name="environment">Additional environment variables.</param>
-        public static BuildScript Create(string exe, string argumentsOpt, bool silent, string? workingDirectory, IDictionary<string, string>? environment) =>
+        public static BuildScript Create(string exe, string? argumentsOpt, bool silent, string? workingDirectory, IDictionary<string, string>? environment) =>
             new BuildCommand(exe, argumentsOpt, silent, workingDirectory, environment);
 
         /// <summary>