Merge pull request #881 from tylergibbs2/detailed-manifest-errors

Add detailed manifest validation errors at build time

1 files changed, 106 insertions, 0 deletions

diff --git a/src/SMAPI.Toolkit/Framework/ManifestValidator.cs b/src/SMAPI.Toolkit/Framework/ManifestValidator.cs
new file mode 100644
index 00000000..461dc325
--- /dev/null
+++ b/src/SMAPI.Toolkit/Framework/ManifestValidator.cs
@@ -0,0 +1,106 @@
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Linq;
+using StardewModdingAPI.Toolkit.Utilities;
+
+namespace StardewModdingAPI.Toolkit.Framework
+{
+    /// <summary>Validates manifest fields.</summary>
+    public static class ManifestValidator
+    {
+        /// <summary>Validate a manifest's fields.</summary>
+        /// <param name="manifest">The manifest to validate.</param>
+        /// <param name="error">The error message indicating why validation failed, if applicable.</param>
+        /// <returns>Returns whether all manifest fields validated successfully.</returns>
+        [SuppressMessage("ReSharper", "ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract", Justification = "This is the method that ensures those annotations are respected.")]
+        public static bool TryValidateFields(IManifest manifest, out string error)
+        {
+            //
+            // Note: SMAPI assumes that it can grammatically append the returned sentence in the
+            // form "failed loading <mod> because its <error>". Any errors returned should be valid
+            // in that format, unless the SMAPI call is adjusted accordingly.
+            //
+
+            bool hasDll = !string.IsNullOrWhiteSpace(manifest.EntryDll);
+            bool isContentPack = manifest.ContentPackFor != null;
+
+            // validate use of EntryDll vs ContentPackFor fields
+            if (hasDll == isContentPack)
+            {
+                error = hasDll
+                    ? $"manifest sets both {nameof(IManifest.EntryDll)} and {nameof(IManifest.ContentPackFor)}, which are mutually exclusive."
+                    : $"manifest has no {nameof(IManifest.EntryDll)} or {nameof(IManifest.ContentPackFor)} field; must specify one.";
+                return false;
+            }
+
+            // validate EntryDll/ContentPackFor format
+            if (hasDll)
+            {
+                if (manifest.EntryDll!.Intersect(Path.GetInvalidFileNameChars()).Any())
+                {
+                    error = $"manifest has invalid filename '{manifest.EntryDll}' for the {nameof(IManifest.EntryDll)} field.";
+                    return false;
+                }
+            }
+            else
+            {
+                if (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 dependency format
+            foreach (IManifestDependency? dependency in manifest.Dependencies)
+            {
+                if (dependency == null)
+                {
+                    error = $"manifest has a null entry under {nameof(IManifest.Dependencies)}.";
+                    return false;
+                }
+
+                if (string.IsNullOrWhiteSpace(dependency.UniqueID))
+                {
+                    error = $"manifest has a {nameof(IManifest.Dependencies)} entry with no {nameof(IManifestDependency.UniqueID)} field.";
+                    return false;
+                }
+
+                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;
+        }
+    }
+}