move validation logic out of Manifest model

This avoids tightly coupling higher logic to the implementation class, since we can validate the interface.

4 files changed, 107 insertions, 95 deletions

diff --git a/src/SMAPI.ModBuildConfig/DeployModTask.cs b/src/SMAPI.ModBuildConfig/DeployModTask.cs
index 357e02b5..70761a2f 100644
--- a/src/SMAPI.ModBuildConfig/DeployModTask.cs
+++ b/src/SMAPI.ModBuildConfig/DeployModTask.cs
@@ -9,6 +9,7 @@ using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 using Newtonsoft.Json;
 using StardewModdingAPI.ModBuildConfig.Framework;
+using StardewModdingAPI.Toolkit.Framework;
 using StardewModdingAPI.Toolkit.Serialization;
 using StardewModdingAPI.Toolkit.Serialization.Models;
 using StardewModdingAPI.Toolkit.Utilities;
@@ -91,7 +92,8 @@ namespace StardewModdingAPI.ModBuildConfig
             try
             {
                 new JsonHelper().ReadJsonFileIfExists(manifestFile.FullName, out manifest);
-            } catch (JsonReaderException ex)
+            }
+            catch (JsonReaderException ex)
             {
                 // log the inner exception, otherwise the message will be generic
                 Exception exToShow = ex.InnerException ?? ex;
@@ -100,7 +102,7 @@ namespace StardewModdingAPI.ModBuildConfig
             }
 
             // validate the manifest's fields
-            if (!manifest.TryValidate(out string error))
+            if (!ManifestValidator.TryValidate(manifest, out string error))
             {
                 this.Log.LogError($"[mod build package] The mod manifest is invalid: {error}");
                 return false;
diff --git a/src/SMAPI.Toolkit/Framework/ManifestValidator.cs b/src/SMAPI.Toolkit/Framework/ManifestValidator.cs
new file mode 100644
index 00000000..62cfd8e9
--- /dev/null
+++ b/src/SMAPI.Toolkit/Framework/ManifestValidator.cs
@@ -0,0 +1,101 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using StardewModdingAPI.Toolkit.Utilities;
+
+namespace StardewModdingAPI.Toolkit.Framework
+{
+    /// <summary>Validates manifest fields.</summary>
+    public static class ManifestValidator
+    {
+        /// <summary>Try to validate a manifest's fields. Fails if any invalid field is found.</summary>
+        /// <param name="manifest">The manifest to validate.</param>
+        /// <param name="error">The error message to display to the user.</param>
+        /// <returns>Returns whether the manifest was validated successfully.</returns>
+        public static bool TryValidate(IManifest manifest, out string error)
+        {
+            // validate DLL / content pack fields
+            bool hasDll = !string.IsNullOrWhiteSpace(manifest.EntryDll);
+            bool isContentPack = manifest.ContentPackFor != null;
+
+            // validate field presence
+            if (!hasDll && !isContentPack)
+            {
+                error = $"manifest has no {nameof(IManifest.EntryDll)} or {nameof(IManifest.ContentPackFor)} field; must specify one.";
+                return false;
+            }
+            if (hasDll && isContentPack)
+            {
+                error = $"manifest sets both {nameof(IManifest.EntryDll)} and {nameof(IManifest.ContentPackFor)}, which are mutually exclusive.";
+                return false;
+            }
+
+            // validate DLL filename format
+            if (hasDll && manifest.EntryDll!.Intersect(Path.GetInvalidFileNameChars()).Any())
+            {
+                error = $"manifest has invalid filename '{manifest.EntryDll}' for the EntryDLL field.";
+                return false;
+            }
+
+            // validate content pack ID
+            else if (isContentPack && string.IsNullOrWhiteSpace(manifest.ContentPackFor!.UniqueID))
+            {
+                error = $"manifest declares {nameof(IManifest.ContentPackFor)} without its required {nameof(IManifestContentPackFor.UniqueID)} field.";
+                return false;
+            }
+
+            // validate required fields
+            {
+                List<string> missingFields = new List<string>(3);
+
+                if (string.IsNullOrWhiteSpace(manifest.Name))
+                    missingFields.Add(nameof(IManifest.Name));
+                if (manifest.Version == null || manifest.Version.ToString() == "0.0.0")
+                    missingFields.Add(nameof(IManifest.Version));
+                if (string.IsNullOrWhiteSpace(manifest.UniqueID))
+                    missingFields.Add(nameof(IManifest.UniqueID));
+
+                if (missingFields.Any())
+                {
+                    error = $"manifest is missing required fields ({string.Join(", ", missingFields)}).";
+                    return false;
+                }
+            }
+
+            // validate ID format
+            if (!PathUtilities.IsSlug(manifest.UniqueID))
+            {
+                error = "manifest specifies an invalid ID (IDs must only contain letters, numbers, underscores, periods, or hyphens).";
+                return false;
+            }
+
+            // validate dependencies
+            foreach (IManifestDependency? dependency in manifest.Dependencies)
+            {
+                // null dependency
+                if (dependency == null)
+                {
+                    error = $"manifest has a null entry under {nameof(IManifest.Dependencies)}.";
+                    return false;
+                }
+
+                // missing ID
+                if (string.IsNullOrWhiteSpace(dependency.UniqueID))
+                {
+                    error = $"manifest has a {nameof(IManifest.Dependencies)} entry with no {nameof(IManifestDependency.UniqueID)} field.";
+                    return false;
+                }
+
+                // invalid ID
+                if (!PathUtilities.IsSlug(dependency.UniqueID))
+                {
+                    error = $"manifest has a {nameof(IManifest.Dependencies)} entry with an invalid {nameof(IManifestDependency.UniqueID)} field (IDs must only contain letters, numbers, underscores, periods, or hyphens).";
+                    return false;
+                }
+            }
+
+            error = "";
+            return true;
+        }
+    }
+}
diff --git a/src/SMAPI.Toolkit/Serialization/Models/Manifest.cs b/src/SMAPI.Toolkit/Serialization/Models/Manifest.cs
index 1607cf3e..8a449f0a 100644
--- a/src/SMAPI.Toolkit/Serialization/Models/Manifest.cs
+++ b/src/SMAPI.Toolkit/Serialization/Models/Manifest.cs
@@ -1,12 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.IO;
-using System.Linq;
 using System.Text;
 using Newtonsoft.Json;
 using StardewModdingAPI.Toolkit.Serialization.Converters;
-using StardewModdingAPI.Toolkit.Utilities;
 
 namespace StardewModdingAPI.Toolkit.Serialization.Models
 {
@@ -106,95 +103,6 @@ namespace StardewModdingAPI.Toolkit.Serialization.Models
             this.UpdateKeys = updateKeys ?? Array.Empty<string>();
         }
 
-        /// <summary>Try to validate a manifest's fields. Fails if any invalid field is found.</summary>
-        /// <param name="error">The error message to display to the user.</param>
-        /// <returns>Returns whether the manifest was validated successfully.</returns>
-        public bool TryValidate(out string error)
-        {
-            // validate DLL / content pack fields
-            bool hasDll = !string.IsNullOrWhiteSpace(this.EntryDll);
-            bool isContentPack = this.ContentPackFor != null;
-
-            // validate field presence
-            if (!hasDll && !isContentPack)
-            {
-                error = $"manifest has no {nameof(IManifest.EntryDll)} or {nameof(IManifest.ContentPackFor)} field; must specify one.";
-                return false;
-            }
-            if (hasDll && isContentPack)
-            {
-                error = $"manifest sets both {nameof(IManifest.EntryDll)} and {nameof(IManifest.ContentPackFor)}, which are mutually exclusive.";
-                return false;
-            }
-
-            // validate DLL filename format
-            if (hasDll && this.EntryDll!.Intersect(Path.GetInvalidFileNameChars()).Any())
-            {
-                error = $"manifest has invalid filename '{this.EntryDll}' for the EntryDLL field.";
-                return false;
-            }
-
-            // validate content pack ID
-            else if (isContentPack && string.IsNullOrWhiteSpace(this.ContentPackFor!.UniqueID))
-            {
-                error = $"manifest declares {nameof(IManifest.ContentPackFor)} without its required {nameof(IManifestContentPackFor.UniqueID)} field.";
-                return false;
-            }
-
-            // validate required fields
-            {
-                List<string> missingFields = new List<string>(3);
-
-                if (string.IsNullOrWhiteSpace(this.Name))
-                    missingFields.Add(nameof(IManifest.Name));
-                if (this.Version == null || this.Version.ToString() == "0.0.0")
-                    missingFields.Add(nameof(IManifest.Version));
-                if (string.IsNullOrWhiteSpace(this.UniqueID))
-                    missingFields.Add(nameof(IManifest.UniqueID));
-
-                if (missingFields.Any())
-                {
-                    error = $"manifest is missing required fields ({string.Join(", ", missingFields)}).";
-                    return false;
-                }
-            }
-
-            // validate ID format
-            if (!PathUtilities.IsSlug(this.UniqueID))
-            {
-                error = "manifest specifies an invalid ID (IDs must only contain letters, numbers, underscores, periods, or hyphens).";
-                return false;
-            }
-
-            // validate dependencies
-            foreach (IManifestDependency? dependency in this.Dependencies)
-            {
-                // null dependency
-                if (dependency == null)
-                {
-                    error = $"manifest has a null entry under {nameof(IManifest.Dependencies)}.";
-                    return false;
-                }
-
-                // missing ID
-                if (string.IsNullOrWhiteSpace(dependency.UniqueID))
-                {
-                    error = $"manifest has a {nameof(IManifest.Dependencies)} entry with no {nameof(IManifestDependency.UniqueID)} field.";
-                    return false;
-                }
-
-                // invalid ID
-                if (!PathUtilities.IsSlug(dependency.UniqueID))
-                {
-                    error = $"manifest has a {nameof(IManifest.Dependencies)} entry with an invalid {nameof(IManifestDependency.UniqueID)} field (IDs must only contain letters, numbers, underscores, periods, or hyphens).";
-                    return false;
-                }
-            }
-
-            error = "";
-            return true;
-        }
-
         /// <summary>Override the update keys loaded from the mod info.</summary>
         /// <param name="updateKeys">The new update keys to set.</param>
         internal void OverrideUpdateKeys(params string[] updateKeys)
diff --git a/src/SMAPI/Framework/ModLoading/ModResolver.cs b/src/SMAPI/Framework/ModLoading/ModResolver.cs
index 352c22cc..0b4fe3e9 100644
--- a/src/SMAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/SMAPI/Framework/ModLoading/ModResolver.cs
@@ -4,6 +4,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using StardewModdingAPI.Toolkit;
+using StardewModdingAPI.Toolkit.Framework;
 using StardewModdingAPI.Toolkit.Framework.ModData;
 using StardewModdingAPI.Toolkit.Framework.ModScanning;
 using StardewModdingAPI.Toolkit.Framework.UpdateData;
@@ -138,7 +139,7 @@ namespace StardewModdingAPI.Framework.ModLoading
                 }
 
                 // validate manifest
-                if (mod.Manifest is Manifest manifest && !manifest.TryValidate(out string manifestError))
+                if (!ManifestValidator.TryValidate(mod.Manifest, out string manifestError))
                 {
                     mod.SetStatus(ModMetadataStatus.Failed, ModFailReason.InvalidManifest, $"its {manifestError}");
                     continue;