simplify beta channel logic (#457)

3 files changed, 20 insertions, 18 deletions

diff --git a/src/SMAPI/Framework/Models/SConfig.cs b/src/SMAPI/Framework/Models/SConfig.cs
index b504f38b..be84a6b9 100644
--- a/src/SMAPI/Framework/Models/SConfig.cs
+++ b/src/SMAPI/Framework/Models/SConfig.cs
@@ -12,6 +12,9 @@ namespace StardewModdingAPI.Framework.Models
         /// <summary>Whether to check for newer versions of SMAPI and mods on startup.</summary>
         public bool CheckForUpdates { get; set; }
 
+        /// <summary>Whether to show beta versions as valid updates.</summary>
+        public bool UseBetaChannel { get; set; } = Constants.ApiVersion.Build != null;
+
         /// <summary>SMAPI's GitHub project name, used to perform update checks.</summary>
         public string GitHubProjectName { get; set; }
 
diff --git a/src/SMAPI/Program.cs b/src/SMAPI/Program.cs
index eda85866..4075dae4 100644
--- a/src/SMAPI/Program.cs
+++ b/src/SMAPI/Program.cs
@@ -550,15 +550,18 @@ namespace StardewModdingAPI
                 try
                 {
                     ModInfoModel response = client.GetModInfo($"GitHub:{this.Settings.GitHubProjectName}").Single().Value;
+                    ISemanticVersion latestStable = response.Version != null ? new SemanticVersion(response.Version) : null;
+                    ISemanticVersion latestBeta = response.PreviewVersion != null ? new SemanticVersion(response.PreviewVersion) : null;
+
                     if (response.Error != null)
                     {
                         this.Monitor.Log("Couldn't check for a new version of SMAPI. This won't affect your game, but you may not be notified of new versions if this keeps happening.", LogLevel.Warn);
                         this.Monitor.Log($"Error: {response.Error}");
                     }
-                    else if (this.IsValidUpdate(Constants.ApiVersion, new SemanticVersion(response.Version)))
-                        this.Monitor.Log($"You can update SMAPI to {response.Version}: {Constants.HomePageUrl}", LogLevel.Alert);
-                    else if (response.PreviewVersion != null && this.IsValidUpdate(Constants.ApiVersion, new SemanticVersion(response.PreviewVersion)))
-                        this.Monitor.Log($"You can update SMAPI to {response.PreviewVersion}: {Constants.HomePageUrl}", LogLevel.Alert);
+                    else if (this.IsValidUpdate(Constants.ApiVersion, latestBeta, this.Settings.UseBetaChannel))
+                        this.Monitor.Log($"You can update SMAPI to {latestBeta}: {Constants.HomePageUrl}", LogLevel.Alert);
+                    else if (this.IsValidUpdate(Constants.ApiVersion, latestStable, this.Settings.UseBetaChannel))
+                        this.Monitor.Log($"You can update SMAPI to {latestStable}: {Constants.HomePageUrl}", LogLevel.Alert);
                     else
                         this.Monitor.Log("   SMAPI okay.", LogLevel.Trace);
                 }
@@ -658,22 +661,12 @@ namespace StardewModdingAPI
         /// <summary>Get whether a given version should be offered to the user as an update.</summary>
         /// <param name="currentVersion">The current semantic version.</param>
         /// <param name="newVersion">The target semantic version.</param>
-        private bool IsValidUpdate(ISemanticVersion currentVersion, ISemanticVersion newVersion)
+        /// <param name="useBetaChannel">Whether the user enabled the beta channel and should be offered pre-release updates.</param>
+        private bool IsValidUpdate(ISemanticVersion currentVersion, ISemanticVersion newVersion, bool useBetaChannel)
         {
-            // basic eligibility
-            bool isNewer = newVersion.IsNewerThan(currentVersion);
-            bool isPrerelease = newVersion.Build != null;
-            bool isEquallyStable = !isPrerelease || currentVersion.Build != null; // don't update stable => prerelease
-            if (!isNewer || !isEquallyStable)
-                return false;
-            if (!isPrerelease)
-                return true;
-
-            // prerelease eligible if same version (excluding prerelease tag)
             return
-                newVersion.MajorVersion == currentVersion.MajorVersion
-                && newVersion.MinorVersion == currentVersion.MinorVersion
-                && newVersion.PatchVersion == currentVersion.PatchVersion;
+                newVersion.IsNewerThan(currentVersion)
+                && (useBetaChannel || newVersion.Build == null);
         }
 
         /// <summary>Create a directory path if it doesn't exist.</summary>
diff --git a/src/SMAPI/StardewModdingAPI.config.json b/src/SMAPI/StardewModdingAPI.config.json
index 06c63e8b..f37c6fc1 100644
--- a/src/SMAPI/StardewModdingAPI.config.json
+++ b/src/SMAPI/StardewModdingAPI.config.json
@@ -22,6 +22,12 @@ This file contains advanced configuration for SMAPI. You generally shouldn't cha
   "CheckForUpdates": true,
 
   /**
+   * Whether SMAPI should show newer beta versions as an available update. If not specified, SMAPI
+   * will only show beta updates if the current version is beta.
+   */
+  //"UseBetaChannel": true,
+
+  /**
    * SMAPI's GitHub project name, used to perform update checks.
    */
   "GitHubProjectName": "Pathoschild/SMAPI",