fix: add helper method to check if version is below or equal to a specific version

backend/src/Designer/Controllers/PreviewController.cs

@@ -13,6 +13,7 @@
 using Altinn.Platform.Storage.Interface.Models;
 using Altinn.Studio.Designer.Filters;
 using Altinn.Studio.Designer.Helpers;
+using Altinn.Studio.Designer.Helpers.Preview;
 using Altinn.Studio.Designer.Infrastructure.GitRepository;
 using Altinn.Studio.Designer.Models;
 using Altinn.Studio.Designer.Models.App;
@@ -61,8 +62,6 @@ public class PreviewController(IHttpContextAccessor httpContextAccessor,
 
         // This value will be overridden to act as the task number for apps that use layout sets
         private const int PartyId = 51001;
-        private const string MINIMUM_NUGET_VERSION = "8.0.0.0";
-        private const int MINIMUM_PREVIEW_NUGET_VERSION = 15;
 
         /// <summary>
         /// Default action for the preview.
@@ -142,7 +141,7 @@ public async Task<ActionResult<ApplicationMetadata>> ApplicationMetadata(string
             ApplicationMetadata applicationMetadata = await altinnAppGitRepository.GetApplicationMetadata(cancellationToken);
             string appNugetVersionString = _appDevelopmentService.GetAppLibVersion(AltinnRepoEditingContext.FromOrgRepoDeveloper(org, app, developer)).ToString();
             // This property is populated at runtime by the apps, so we need to mock it here
-            applicationMetadata.AltinnNugetVersion = GetMockedAltinnNugetBuildFromVersion(appNugetVersionString);
+            applicationMetadata.AltinnNugetVersion = NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion(appNugetVersionString);
             applicationMetadata = SetMockedPartyTypesAllowedAsAllFalse(applicationMetadata);
             return Ok(applicationMetadata);
         }
@@ -695,29 +694,6 @@ private static string ReplaceIndexToFetchCorrectOrgAppInCshtml(string originalCo
             return modifiedContent;
         }
 
-        /// <summary>
-        /// Method to get the mocked altinn nuget build from the version
-        /// We are returnning the minimum BUILD version of the nuget package that is required for app frontend to work
-        /// from v4 and above.
-        /// </summary>
-        /// <param name="version">The version of the nuget package</param>
-        /// <returns>The minimum build version of the nuget package</returns>
-        private string GetMockedAltinnNugetBuildFromVersion(string version)
-        {
-
-            string[] versionParts = version.Split('.');
-            if (!IsValidSemVerVersion(versionParts))
-            {
-                return string.Empty;
-            }
-
-            if (IsPreviewVersion(versionParts) && GetPreviewVersion(versionParts) < MINIMUM_PREVIEW_NUGET_VERSION)
-            {
-                return string.Empty;
-            }
-
-            return MINIMUM_NUGET_VERSION;
-        }
 
         /// <summary>
         /// Method to override the partyTypesAllowed in app metadata to bypass the check in app-frontend for a valid party during instantiation.
@@ -733,19 +709,5 @@ private static ApplicationMetadata SetMockedPartyTypesAllowedAsAllFalse(Applicat
             return applicationMetadata;
         }
 
-        private bool IsValidSemVerVersion(string[] versionParts)
-        {
-            return versionParts.Length >= 3 && Convert.ToInt32(versionParts[0]) >= 8;
-        }
-
-        private bool IsPreviewVersion(string[] versionParts)
-        {
-            return versionParts[2].Contains("-preview") && versionParts.Length == 4;
-        }
-
-        private int GetPreviewVersion(string[] versionParts)
-        {
-            return Convert.ToInt32(versionParts[3]);
-        }
     }
 }

backend/src/Designer/Helpers/Preview/NugetVersionHelper.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Diagnostics.Contracts;
+using System.Linq;
+
+namespace Altinn.Studio.Designer.Helpers.Preview
+{
+    public static class NugetVersionHelper
+    {
+        private const string MINIMUM_NUGET_VERSION = "8.0.0.0";
+        private const int MINIMUM_PREVIEW_NUGET_VERSION = 15;
+
+        /// <summary>
+        /// Method to get the mocked altinn nuget build from the version
+        /// We are returnning the minimum BUILD version of the nuget package that is required for app frontend to work
+        /// from v4 and above.
+        /// </summary>
+        /// <param name="version">The version of the nuget package</param>
+        /// <returns>The minimum build version of the nuget package</returns>
+        public static string GetMockedAltinnNugetBuildFromVersion(string version)
+        {
+
+            string[] versionParts = version.Split('.');
+            if (!IsValidSemVerVersion(versionParts))
+            {
+                return string.Empty;
+            }
+
+            string normalVersion = version.Split('-').First();
+            int[] numberVersion = [.. normalVersion.Split('.').Take(3).Select((split) => Convert.ToInt32(split))];
+            if (IsVersionOrBelow(numberVersion, [8, 0, 0]) && IsPreviewVersion(versionParts) && GetPreviewVersion(versionParts) < MINIMUM_PREVIEW_NUGET_VERSION)
+            {
+                return string.Empty;
+            }
+
+            return MINIMUM_NUGET_VERSION;
+        }
+
+        private static bool IsValidSemVerVersion(string[] versionParts)
+        {
+            return versionParts.Length >= 3 && Convert.ToInt32(versionParts[0]) >= 8;
+        }
+
+        // <exception cref="FormatException"></exception>
+        // <exception cref="OverflowException"></exception>
+        private static bool IsVersionOrBelow(int[] versionParts, int[] breakpoint)
+        {
+            Contract.Requires(versionParts.Length == 3);
+            Contract.Requires(breakpoint.Length == 3);
+            for (int i = 0; i < 3; i++)
+            {
+                if (versionParts[i] > breakpoint[i])
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        private static bool IsPreviewVersion(string[] versionParts)
+        {
+            return versionParts[2].Contains("-preview") && versionParts.Length == 4;
+        }
+
+        private static int GetPreviewVersion(string[] versionParts)
+        {
+            return Convert.ToInt32(versionParts[3]);
+        }
+    }
+}

backend/tests/Designer.Tests/Helpers/Preview/NugetVersionHelperTests.cs

@@ -0,0 +1,24 @@
+using Altinn.Studio.Designer.Helpers.Preview;
+using Xunit;
+
+namespace Designer.Tests.Helpers.Preview
+{
+
+    public class NugetVersionHelperTests
+    {
+        [Fact]
+        public void GetMockedAltinnNugetBuildFromVersion_ShouldReturnEmptyStringForVersionsBelowBreakpoint()
+        {
+            Assert.Equal("", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("1.1.1"));
+            Assert.Equal("", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("1.1.1-preview.150"));
+            Assert.Equal("", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("1.1.1-preview.0"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.1.1-preview.14"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.8.8-preview.0"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.18.1238"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.18.1238"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.8.8-preview.342"));
+            Assert.Equal("8.0.0.0", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.0.0-preview.15"));
+            Assert.Equal("", NugetVersionHelper.GetMockedAltinnNugetBuildFromVersion("8.0.0-preview.14"));
+        }
+    }
+}