public static VisualStudioInstance GetInstance()

in src/MSBuildLocator/DotNetSdkLocationHelper.cs [20:68]
42 lines of code
12 McCabe index (conditional complexity)

        public static VisualStudioInstance GetInstance(string dotNetSdkPath)
        {            
            if (string.IsNullOrWhiteSpace(dotNetSdkPath))
            {
                return null;
            }

            if (!File.Exists(Path.Combine(dotNetSdkPath, "Microsoft.Build.dll")))
            {
                return null;
            }

            string versionPath = Path.Combine(dotNetSdkPath, ".version");
            if (!File.Exists(versionPath))
            {
                return null;
            }

            // Preview versions contain a hyphen after the numeric part of the version. Version.TryParse doesn't accept that.
            Match versionMatch = VersionRegex.Match(File.ReadAllText(versionPath));

            if (!versionMatch.Success)
            {
                return null;
            }

            if (!int.TryParse(versionMatch.Groups[1].Value, out int major) ||
                !int.TryParse(versionMatch.Groups[2].Value, out int minor) ||
                !int.TryParse(versionMatch.Groups[3].Value, out int patch))
            {
                return null;
            }
            
            // Components of the SDK often have dependencies on the runtime they shipped with, including that several tasks that shipped
            // in the .NET 5 SDK rely on the .NET 5.0 runtime. Assuming the runtime that shipped with a particular SDK has the same version,
            // this ensures that we don't choose an SDK that doesn't work with the runtime of the chosen application. This is not guaranteed
            // to always work but should work for now.
            if (major > Environment.Version.Major ||
                (major == Environment.Version.Major && minor > Environment.Version.Minor))
            {
                return null;
            }

            return new VisualStudioInstance(
                name: ".NET Core SDK",
                path: dotNetSdkPath,
                version: new Version(major, minor, patch),
                discoveryType: DiscoveryType.DotNetSdk);
        }