Add Type to relationshipWasNil RuneError (#86)

* Add Type to relationshipWasNil RuneError

Co-authored-by: Sean Miller <sean@withapollo.com>

Author: seanmiller802

Sources/Alchemy/SQL/Rune/Relationships/Relationship.swift

@@ -52,7 +52,7 @@ public protocol RelationshipAllowed {
 
 extension Model {
     public static func from(_ value: Self?) throws -> Self {
-        try value.unwrap(or: RuneError.relationshipWasNil)
+        try value.unwrap(or: RuneError.relationshipWasNil(type: Self.self))
     }
 }
 

Sources/Alchemy/SQL/Rune/RuneError.swift

@@ -14,7 +14,9 @@ public struct RuneError: Error {
     public static let notFound = RuneError("Unable to find an element of this type.")
 
     /// Couldn't unwrap a relationship that was expected to be nonnil.
-    public static let relationshipWasNil = RuneError("This non-optional relationship had no matching models.")
+    public static func relationshipWasNil<M: Model>(type: M.Type) -> RuneError {
+        RuneError("This non-optional relationship to \(type) has no matching models.")
+    }
 
     /// Couldn't sync a model; its id was nil.
     public static let syncErrorNoId = RuneError("Can't .sync() an object with a nil `id`.")