enable nullable annotations in bundled mods (#837)

45 files changed, 92 insertions, 173 deletions

diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ArgumentParser.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ArgumentParser.cs
index 8fcbf711..66f2f105 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ArgumentParser.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ArgumentParser.cs
@@ -1,8 +1,7 @@
-#nullable disable
-
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 
 namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands
@@ -54,7 +53,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands
         /// <param name="value">The parsed value.</param>
         /// <param name="required">Whether to show an error if the argument is missing.</param>
         /// <param name="oneOf">Require that the argument match one of the given values (case-insensitive).</param>
-        public bool TryGet(int index, string name, out string value, bool required = true, string[] oneOf = null)
+        public bool TryGet(int index, string name, [NotNullWhen(true)] out string? value, bool required = true, string[]? oneOf = null)
         {
             value = null;
 
@@ -88,7 +87,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands
             value = 0;
 
             // get argument
-            if (!this.TryGet(index, name, out string raw, required))
+            if (!this.TryGet(index, name, out string? raw, required))
                 return false;
 
             // parse
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ConsoleCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ConsoleCommand.cs
index a8dd41f5..44b7824e 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ConsoleCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/ConsoleCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/IConsoleCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/IConsoleCommand.cs
index 4c6df538..9c82bbd3 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/IConsoleCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/IConsoleCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands
 {
     /// <summary>A console command to register.</summary>
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ApplySaveFixCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ApplySaveFixCommand.cs
index f31457ed..f2194cff 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ApplySaveFixCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ApplySaveFixCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -25,7 +23,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Other
         public override void Handle(IMonitor monitor, string command, ArgumentParser args)
         {
             // get fix ID
-            if (!args.TryGet(0, "fix_id", out string rawFixId, required: false))
+            if (!args.TryGet(0, "fix_id", out string? rawFixId, required: false))
             {
                 monitor.Log("Invalid usage. Type 'help apply_save_fix' for details.", LogLevel.Error);
                 return;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/DebugCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/DebugCommand.cs
index f289c669..cf1dcbce 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/DebugCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/DebugCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/RegenerateBundles.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/RegenerateBundles.cs
index 81a8c570..159d7c4a 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/RegenerateBundles.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/RegenerateBundles.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowDataFilesCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowDataFilesCommand.cs
index d762d8bf..a233d588 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowDataFilesCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowDataFilesCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowGameFilesCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowGameFilesCommand.cs
index b5733eb9..745b821b 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowGameFilesCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ShowGameFilesCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/TestInputCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/TestInputCommand.cs
index 5484fc7c..8bf9f5db 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/TestInputCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/TestInputCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/AddCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/AddCommand.cs
index 0d8db870..74d3d9df 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/AddCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/AddCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Linq;
 using StardewModdingAPI.Mods.ConsoleCommands.Framework.ItemData;
@@ -42,7 +40,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
             }
 
             // read arguments
-            if (!args.TryGet(0, "item type", out string type, oneOf: this.ValidTypes))
+            if (!args.TryGet(0, "item type", out string? type, oneOf: this.ValidTypes))
                 return;
             if (!args.TryGetInt(2, "count", out int count, min: 1, required: false))
                 count = 1;
@@ -50,7 +48,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
                 quality = Object.lowQuality;
 
             // find matching item
-            SearchableItem match = Enum.TryParse(type, true, out ItemType itemType)
+            SearchableItem? match = Enum.TryParse(type, true, out ItemType itemType)
                 ? this.FindItemByID(monitor, args, itemType)
                 : this.FindItemByName(monitor, args);
             if (match == null)
@@ -78,14 +76,14 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         /// <param name="monitor">Writes messages to the console and log file.</param>
         /// <param name="args">The command arguments.</param>
         /// <param name="type">The item type.</param>
-        private SearchableItem FindItemByID(IMonitor monitor, ArgumentParser args, ItemType type)
+        private SearchableItem? FindItemByID(IMonitor monitor, ArgumentParser args, ItemType type)
         {
             // read arguments
             if (!args.TryGetInt(1, "item ID", out int id, min: 0))
                 return null;
 
             // find matching item
-            SearchableItem item = this.Items.GetAll().FirstOrDefault(p => p.Type == type && p.ID == id);
+            SearchableItem? item = this.Items.GetAll().FirstOrDefault(p => p.Type == type && p.ID == id);
             if (item == null)
                 monitor.Log($"There's no {type} item with ID {id}.", LogLevel.Error);
             return item;
@@ -94,10 +92,10 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         /// <summary>Get a matching item by its name.</summary>
         /// <param name="monitor">Writes messages to the console and log file.</param>
         /// <param name="args">The command arguments.</param>
-        private SearchableItem FindItemByName(IMonitor monitor, ArgumentParser args)
+        private SearchableItem? FindItemByName(IMonitor monitor, ArgumentParser args)
         {
             // read arguments
-            if (!args.TryGet(1, "item name", out string name))
+            if (!args.TryGet(1, "item name", out string? name))
                 return null;
 
             // find matching items
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemTypesCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemTypesCommand.cs
index e57d4065..ef35ad19 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemTypesCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemTypesCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewModdingAPI.Mods.ConsoleCommands.Framework.ItemData;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemsCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemsCommand.cs
index 5a21b459..73d5b79d 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemsCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/ListItemsCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -63,15 +61,14 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         private IEnumerable<SearchableItem> GetItems(string[] searchWords)
         {
             // normalize search term
-            searchWords = searchWords?.Where(word => !string.IsNullOrWhiteSpace(word)).ToArray();
-            if (searchWords?.Any() == false)
-                searchWords = null;
+            searchWords = searchWords.Where(word => !string.IsNullOrWhiteSpace(word)).ToArray();
+            bool getAll = !searchWords.Any();
 
             // find matches
             return (
                 from item in this.Items.GetAll()
                 let term = $"{item.ID}|{item.Type}|{item.Name}|{item.DisplayName}"
-                where searchWords == null || searchWords.All(word => term.IndexOf(word, StringComparison.CurrentCultureIgnoreCase) != -1)
+                where getAll || searchWords.All(word => term.IndexOf(word, StringComparison.CurrentCultureIgnoreCase) != -1)
                 select item
             );
         }
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetColorCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetColorCommand.cs
index e8605163..12a51bc9 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetColorCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetColorCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.Xna.Framework;
 using StardewValley;
@@ -24,9 +22,9 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         public override void Handle(IMonitor monitor, string command, ArgumentParser args)
         {
             // parse arguments
-            if (!args.TryGet(0, "target", out string target, oneOf: new[] { "hair", "eyes", "pants" }))
+            if (!args.TryGet(0, "target", out string? target, oneOf: new[] { "hair", "eyes", "pants" }))
                 return;
-            if (!args.TryGet(1, "color", out string rawColor))
+            if (!args.TryGet(1, "color", out string? rawColor))
                 return;
 
             // parse color
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetFarmTypeCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetFarmTypeCommand.cs
index 02670911..b2035d42 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetFarmTypeCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetFarmTypeCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections;
 using System.Collections.Generic;
@@ -37,7 +35,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
             }
 
             // parse arguments
-            if (!args.TryGet(0, "farm type", out string farmType))
+            if (!args.TryGet(0, "farm type", out string? farmType))
                 return;
             bool isVanillaId = int.TryParse(farmType, out int vanillaId) && vanillaId is (>= 0 and < Farm.layout_max);
 
@@ -112,7 +110,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
                 return;
             }
 
-            if (!this.GetCustomFarmTypes().TryGetValue(id, out ModFarmType customFarmType))
+            if (!this.GetCustomFarmTypes().TryGetValue(id, out ModFarmType? customFarmType))
             {
                 monitor.Log($"Invalid farm type '{id}'. Enter `help set_farm_type` for more info.", LogLevel.Error);
                 return;
@@ -125,7 +123,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         /// <summary>Change the farm type.</summary>
         /// <param name="type">The farm type ID.</param>
         /// <param name="customFarmData">The custom farm type data, if applicable.</param>
-        private void SetFarmType(int type, ModFarmType customFarmData)
+        private void SetFarmType(int type, ModFarmType? customFarmData)
         {
             // set flags
             Game1.whichFarm = type;
@@ -138,7 +136,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
             farm.updateWarps();
 
             // clear spouse area cache to avoid errors
-            FieldInfo cacheField = farm.GetType().GetField("_baseSpouseAreaTiles", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
+            FieldInfo? cacheField = farm.GetType().GetField("_baseSpouseAreaTiles", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
             if (cacheField == null)
                 throw new InvalidOperationException("Failed to access '_baseSpouseAreaTiles' field to clear spouse area cache.");
             if (cacheField.GetValue(farm) is not IDictionary cache)
@@ -166,7 +164,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         /// <param name="type">The farm type.</param>
         private string GetVanillaName(int type)
         {
-            string translationKey = type switch
+            string? translationKey = type switch
             {
                 Farm.default_layout => "Character_FarmStandard",
                 Farm.riverlands_layout => "Character_FarmFishing",
@@ -199,7 +197,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         ****/
         /// <summary>Get the display name for a custom farm type.</summary>
         /// <param name="farmType">The custom farm type.</param>
-        private string GetCustomName(ModFarmType farmType)
+        private string? GetCustomName(ModFarmType? farmType)
         {
             if (string.IsNullOrWhiteSpace(farmType?.TooltipStringPath))
                 return farmType?.ID;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetHealthCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetHealthCommand.cs
index 1a1a9eab..f169159f 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetHealthCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetHealthCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetImmunityCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetImmunityCommand.cs
index d1dede1f..1065bd21 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetImmunityCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetImmunityCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxHealthCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxHealthCommand.cs
index 2b3b140c..c2c4931d 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxHealthCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxHealthCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxStaminaCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxStaminaCommand.cs
index f9ed6c58..8c794e75 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxStaminaCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMaxStaminaCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMoneyCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMoneyCommand.cs
index 56447a65..3afcc62b 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMoneyCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetMoneyCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetNameCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetNameCommand.cs
index 4ce7e1f8..37c02ed0 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetNameCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetNameCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
 
@@ -23,9 +21,9 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         public override void Handle(IMonitor monitor, string command, ArgumentParser args)
         {
             // parse arguments
-            if (!args.TryGet(0, "target", out string target, oneOf: new[] { "player", "farm" }))
+            if (!args.TryGet(0, "target", out string? target, oneOf: new[] { "player", "farm" }))
                 return;
-            args.TryGet(1, "name", out string name, required: false);
+            args.TryGet(1, "name", out string? name, required: false);
 
             // handle
             switch (target)
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStaminaCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStaminaCommand.cs
index ea8d74c2..24718ace 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStaminaCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStaminaCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStyleCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStyleCommand.cs
index 84625a34..8193ff27 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStyleCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Player/SetStyleCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
 
@@ -23,7 +21,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Player
         public override void Handle(IMonitor monitor, string command, ArgumentParser args)
         {
             // parse arguments
-            if (!args.TryGet(0, "target", out string target, oneOf: new[] { "hair", "shirt", "acc", "skin", "shoe", "swim", "gender" }))
+            if (!args.TryGet(0, "target", out string? target, oneOf: new[] { "hair", "shirt", "acc", "skin", "shoe", "swim", "gender" }))
                 return;
             if (!args.TryGetInt(1, "style ID", out int styleID))
                 return;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/ClearCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/ClearCommand.cs
index 92c73e08..4905b89a 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/ClearCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/ClearCommand.cs
@@ -1,8 +1,7 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Microsoft.Xna.Framework;
 using StardewValley;
 using StardewValley.Locations;
 using StardewValley.Objects;
@@ -53,13 +52,13 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.World
             }
 
             // parse arguments
-            if (!args.TryGet(0, "location", out string locationName, required: true))
+            if (!args.TryGet(0, "location", out string? locationName, required: true))
                 return;
-            if (!args.TryGet(1, "object type", out string type, required: true, oneOf: this.ValidTypes))
+            if (!args.TryGet(1, "object type", out string? type, required: true, oneOf: this.ValidTypes))
                 return;
 
             // get target location
-            GameLocation location = Game1.locations.FirstOrDefault(p => p.Name != null && p.Name.Equals(locationName, StringComparison.OrdinalIgnoreCase));
+            GameLocation? location = Game1.locations.FirstOrDefault(p => p.Name != null && p.Name.Equals(locationName, StringComparison.OrdinalIgnoreCase));
             if (location == null && locationName == "current")
                 location = Game1.currentLocation;
             if (location == null)
@@ -168,11 +167,11 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.World
         {
             int removed = 0;
 
-            foreach (var pair in location.Objects.Pairs.ToArray())
+            foreach ((Vector2 tile, SObject? obj) in location.Objects.Pairs.ToArray())
             {
-                if (shouldRemove(pair.Value))
+                if (shouldRemove(obj))
                 {
-                    location.Objects.Remove(pair.Key);
+                    location.Objects.Remove(tile);
                     removed++;
                 }
             }
@@ -188,11 +187,11 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.World
         {
             int removed = 0;
 
-            foreach (var pair in location.terrainFeatures.Pairs.ToArray())
+            foreach ((Vector2 tile, TerrainFeature? feature) in location.terrainFeatures.Pairs.ToArray())
             {
-                if (shouldRemove(pair.Value))
+                if (shouldRemove(feature))
                 {
-                    location.terrainFeatures.Remove(pair.Key);
+                    location.terrainFeatures.Remove(tile);
                     removed++;
                 }
             }
@@ -228,7 +227,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.World
         {
             int removed = 0;
 
-            foreach (var clump in location.resourceClumps.Where(shouldRemove).ToArray())
+            foreach (ResourceClump clump in location.resourceClumps.Where(shouldRemove).ToArray())
             {
                 location.resourceClumps.Remove(clump);
                 removed++;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/DownMineLevelCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/DownMineLevelCommand.cs
index 0f18c760..5b1a4a13 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/DownMineLevelCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/DownMineLevelCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
 using StardewValley.Locations;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/FreezeTimeCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/FreezeTimeCommand.cs
index 8808fe35..16faa2fe 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/FreezeTimeCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/FreezeTimeCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Linq;
 using StardewValley;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/HurryAllCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/HurryAllCommand.cs
index f9810dc3..09531720 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/HurryAllCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/HurryAllCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetDayCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetDayCommand.cs
index 8aa27d93..399fd934 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetDayCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetDayCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewModdingAPI.Utilities;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetMineLevelCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetMineLevelCommand.cs
index ad6ac777..f977fce3 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetMineLevelCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetMineLevelCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using StardewValley;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetSeasonCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetSeasonCommand.cs
index ebe58913..505c0d1d 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetSeasonCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetSeasonCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewModdingAPI.Utilities;
@@ -39,7 +37,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.World
             }
 
             // parse arguments
-            if (!args.TryGet(0, "season", out string season, oneOf: this.ValidSeasons))
+            if (!args.TryGet(0, "season", out string? season, oneOf: this.ValidSeasons))
                 return;
 
             // handle
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetTimeCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetTimeCommand.cs
index 1e6bab96..8c4458dd 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetTimeCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetTimeCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Microsoft.Xna.Framework;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetYearCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetYearCommand.cs
index 995f222e..a666a634 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetYearCommand.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/World/SetYearCommand.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using StardewModdingAPI.Utilities;
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/ItemData/SearchableItem.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/ItemData/SearchableItem.cs
index ab0b2e05..3675a963 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/ItemData/SearchableItem.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/ItemData/SearchableItem.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using StardewValley;
 
diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/ItemRepository.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/ItemRepository.cs
index 7d2a1662..3722e155 100644
--- a/src/SMAPI.Mods.ConsoleCommands/Framework/ItemRepository.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/ItemRepository.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -33,7 +31,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
         /// <param name="itemTypes">The item types to fetch (or null for any type).</param>
         /// <param name="includeVariants">Whether to include flavored variants like "Sunflower Honey".</param>
         [SuppressMessage("ReSharper", "AccessToModifiedClosure", Justification = "TryCreate invokes the lambda immediately.")]
-        public IEnumerable<SearchableItem> GetAll(ItemType[] itemTypes = null, bool includeVariants = true)
+        public IEnumerable<SearchableItem> GetAll(ItemType[]? itemTypes = null, bool includeVariants = true)
         {
             //
             //
@@ -45,9 +43,9 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
             //
             //
 
-            IEnumerable<SearchableItem> GetAllRaw()
+            IEnumerable<SearchableItem?> GetAllRaw()
             {
-                HashSet<ItemType> types = itemTypes?.Any() == true ? new HashSet<ItemType>(itemTypes) : null;
+                HashSet<ItemType>? types = itemTypes?.Any() == true ? new HashSet<ItemType>(itemTypes) : null;
                 bool ShouldGet(ItemType type) => types == null || types.Contains(type);
 
                 // get tools
@@ -134,7 +132,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                 {
                     foreach (int id in Game1.objectInformation.Keys)
                     {
-                        string[] fields = Game1.objectInformation[id]?.Split('/');
+                        string[]? fields = Game1.objectInformation[id]?.Split('/');
 
                         // ring
                         if (id != 801 && fields?.Length >= 4 && fields[3] == "Ring") // 801 = wedding ring, which isn't an equippable ring
@@ -148,7 +146,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                         {
                             if (ShouldGet(ItemType.Object))
                             {
-                                foreach (SearchableItem journalScrap in this.GetSecretNotes(isJournalScrap: true))
+                                foreach (SearchableItem? journalScrap in this.GetSecretNotes(isJournalScrap: true))
                                     yield return journalScrap;
                             }
                         }
@@ -158,7 +156,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                         {
                             if (ShouldGet(ItemType.Object))
                             {
-                                foreach (SearchableItem secretNote in this.GetSecretNotes(isJournalScrap: false))
+                                foreach (SearchableItem? secretNote in this.GetSecretNotes(isJournalScrap: false))
                                     yield return secretNote;
                             }
                         }
@@ -167,7 +165,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                         else if (ShouldGet(ItemType.Object))
                         {
                             // spawn main item
-                            SObject item = null;
+                            SObject? item = null;
                             yield return this.TryCreate(ItemType.Object, id, p =>
                             {
                                 return item = (p.ID == 812 // roe
@@ -181,7 +179,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                             // flavored items
                             if (includeVariants)
                             {
-                                foreach (SearchableItem variant in this.GetFlavoredObjectVariants(item))
+                                foreach (SearchableItem? variant in this.GetFlavoredObjectVariants(item))
                                     yield return variant;
                             }
                         }
@@ -189,7 +187,11 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                 }
             }
 
-            return GetAllRaw().Where(p => p != null);
+            return (
+                from item in GetAllRaw()
+                where item != null
+                select item
+            );
         }
 
 
@@ -199,7 +201,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
         /// <summary>Get the individual secret note or journal scrap items.</summary>
         /// <param name="isJournalScrap">Whether to get journal scraps.</param>
         /// <remarks>Derived from <see cref="GameLocation.tryToCreateUnseenSecretNote"/>.</remarks>
-        private IEnumerable<SearchableItem> GetSecretNotes(bool isJournalScrap)
+        private IEnumerable<SearchableItem?> GetSecretNotes(bool isJournalScrap)
         {
             // get base item ID
             int baseId = isJournalScrap ? 842 : 79;
@@ -235,7 +237,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
 
         /// <summary>Get flavored variants of a base item (like Blueberry Wine for Blueberry), if any.</summary>
         /// <param name="item">A sample of the base item.</param>
-        private IEnumerable<SearchableItem> GetFlavoredObjectVariants(SObject item)
+        private IEnumerable<SearchableItem?> GetFlavoredObjectVariants(SObject item)
         {
             int id = item.ParentSheetIndex;
 
@@ -305,9 +307,12 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                         foreach (var pair in Game1.objectInformation)
                         {
                             // get input
-                            SObject input = this.TryCreate(ItemType.Object, pair.Key, p => new SObject(p.ID, 1))?.Item as SObject;
-                            var inputTags = input?.GetContextTags();
-                            if (inputTags?.Any() != true)
+                            SObject? input = this.TryCreate(ItemType.Object, pair.Key, p => new SObject(p.ID, 1))?.Item as SObject;
+                            if (input == null)
+                                continue;
+
+                            HashSet<string> inputTags = input.GetContextTags();
+                            if (!inputTags.Any())
                                 continue;
 
                             // check if roe-producing fish
@@ -315,7 +320,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
                                 continue;
 
                             // yield roe
-                            SObject roe = null;
+                            SObject? roe = null;
                             Color color = this.GetRoeColor(input);
                             yield return this.TryCreate(ItemType.Object, this.CustomIDOffset * 7 + id, _ =>
                             {
@@ -372,6 +377,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
         /// <typeparam name="TValue">The asset value type.</typeparam>
         /// <param name="assetName">The data asset name.</param>
         private Dictionary<TKey, TValue> TryLoad<TKey, TValue>(string assetName)
+            where TKey : notnull
         {
             try
             {
@@ -388,7 +394,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands.Framework
         /// <param name="type">The item type.</param>
         /// <param name="id">The unique ID (if different from the item's parent sheet index).</param>
         /// <param name="createItem">Create an item instance.</param>
-        private SearchableItem TryCreate(ItemType type, int id, Func<SearchableItem, Item> createItem)
+        private SearchableItem? TryCreate(ItemType type, int id, Func<SearchableItem, Item> createItem)
         {
             try
             {
diff --git a/src/SMAPI.Mods.ConsoleCommands/ModEntry.cs b/src/SMAPI.Mods.ConsoleCommands/ModEntry.cs
index e3ca1a39..dbfca815 100644
--- a/src/SMAPI.Mods.ConsoleCommands/ModEntry.cs
+++ b/src/SMAPI.Mods.ConsoleCommands/ModEntry.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -15,13 +13,13 @@ namespace StardewModdingAPI.Mods.ConsoleCommands
         ** Fields
         *********/
         /// <summary>The commands to handle.</summary>
-        private IConsoleCommand[] Commands;
+        private IConsoleCommand[] Commands = null!;
 
         /// <summary>The commands which may need to handle update ticks.</summary>
-        private IConsoleCommand[] UpdateHandlers;
+        private IConsoleCommand[] UpdateHandlers = null!;
 
         /// <summary>The commands which may need to handle input.</summary>
-        private IConsoleCommand[] InputHandlers;
+        private IConsoleCommand[] InputHandlers = null!;
 
 
         /*********
@@ -52,7 +50,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands
         /// <summary>The method invoked when a button is pressed.</summary>
         /// <param name="sender">The event sender.</param>
         /// <param name="e">The event arguments.</param>
-        private void OnButtonPressed(object sender, ButtonPressedEventArgs e)
+        private void OnButtonPressed(object? sender, ButtonPressedEventArgs e)
         {
             foreach (IConsoleCommand command in this.InputHandlers)
                 command.OnButtonPressed(this.Monitor, e.Button);
@@ -61,7 +59,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands
         /// <summary>The method invoked when the game updates its state.</summary>
         /// <param name="sender">The event sender.</param>
         /// <param name="e">The event arguments.</param>
-        private void OnUpdateTicked(object sender, EventArgs e)
+        private void OnUpdateTicked(object? sender, EventArgs e)
         {
             foreach (IConsoleCommand command in this.UpdateHandlers)
                 command.OnUpdated(this.Monitor);
@@ -83,7 +81,7 @@ namespace StardewModdingAPI.Mods.ConsoleCommands
             return (
                 from type in this.GetType().Assembly.GetTypes()
                 where !type.IsAbstract && typeof(IConsoleCommand).IsAssignableFrom(type)
-                select (IConsoleCommand)Activator.CreateInstance(type)
+                select (IConsoleCommand)Activator.CreateInstance(type)!
             );
         }
     }
diff --git a/src/SMAPI.Mods.ErrorHandler/ModEntry.cs b/src/SMAPI.Mods.ErrorHandler/ModEntry.cs
index fa171012..bfbfd2dc 100644
--- a/src/SMAPI.Mods.ErrorHandler/ModEntry.cs
+++ b/src/SMAPI.Mods.ErrorHandler/ModEntry.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Reflection;
 using StardewModdingAPI.Events;
@@ -59,7 +57,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler
         /// <summary>The method invoked when a save is loaded.</summary>
         /// <param name="sender">The event sender.</param>
         /// <param name="e">The event arguments.</param>
-        private void OnSaveLoaded(object sender, SaveLoadedEventArgs e)
+        private void OnSaveLoaded(object? sender, SaveLoadedEventArgs e)
         {
             // show in-game warning for removed save content
             if (this.IsSaveContentRemoved)
@@ -82,7 +80,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler
             MethodInfo getMonitorForGame = coreType.GetMethod("GetMonitorForGame")
                 ?? throw new InvalidOperationException("Can't access the SMAPI's 'GetMonitorForGame' method. This mod may not work correctly.");
 
-            return (IMonitor)getMonitorForGame.Invoke(core, Array.Empty<object>()) ?? this.Monitor;
+            return (IMonitor?)getMonitorForGame.Invoke(core, Array.Empty<object>()) ?? this.Monitor;
         }
     }
 }
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/DialoguePatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/DialoguePatcher.cs
index b05c8cca..e98eec3c 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/DialoguePatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/DialoguePatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
@@ -19,10 +17,10 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         ** Fields
         *********/
         /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
-        private static IMonitor MonitorForGame;
+        private static IMonitor MonitorForGame = null!;
 
         /// <summary>Simplifies access to private code.</summary>
-        private static IReflectionHelper Reflection;
+        private static IReflectionHelper Reflection = null!;
 
 
         /*********
@@ -56,12 +54,12 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="speaker">The NPC for which the dialogue is being parsed.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_Constructor(Dialogue __instance, string masterDialogue, NPC speaker, Exception __exception)
+        private static Exception? Finalize_Constructor(Dialogue __instance, string masterDialogue, NPC? speaker, Exception? __exception)
         {
             if (__exception != null)
             {
                 // log message
-                string name = !string.IsNullOrWhiteSpace(speaker?.Name) ? speaker.Name : null;
+                string? name = !string.IsNullOrWhiteSpace(speaker?.Name) ? speaker.Name : null;
                 DialoguePatcher.MonitorForGame.Log($"Failed parsing dialogue string{(name != null ? $" for {name}" : "")}:\n{masterDialogue}\n{__exception.GetLogSummary()}", LogLevel.Error);
 
                 // set default dialogue
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/EventPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/EventPatcher.cs
index 63674d09..073c62cc 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/EventPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/EventPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
@@ -18,7 +16,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         ** Fields
         *********/
         /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
-        private static IMonitor MonitorForGame;
+        private static IMonitor MonitorForGame = null!;
 
 
         /*********
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/GameLocationPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/GameLocationPatcher.cs
index 98aa4a38..9247fa48 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/GameLocationPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/GameLocationPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
@@ -19,8 +17,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         ** Fields
         *********/
         /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
-        private static IMonitor MonitorForGame;
-
+        private static IMonitor MonitorForGame = null!;
 
         /*********
         ** Public methods
@@ -54,7 +51,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="precondition">The precondition to be parsed.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_CheckEventPrecondition(ref int __result, string precondition, Exception __exception)
+        private static Exception? Finalize_CheckEventPrecondition(ref int __result, string precondition, Exception? __exception)
         {
             if (__exception != null)
             {
@@ -70,7 +67,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="map">The map whose tilesheets to update.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_UpdateSeasonalTileSheets(GameLocation __instance, Map map, Exception __exception)
+        private static Exception? Finalize_UpdateSeasonalTileSheets(GameLocation __instance, Map map, Exception? __exception)
         {
             if (__exception != null)
                 GameLocationPatcher.MonitorForGame.Log($"Failed updating seasonal tilesheets for location '{__instance.NameOrUniqueName}': \n{__exception}", LogLevel.Error);
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/IClickableMenuPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/IClickableMenuPatcher.cs
index 85ce8ac4..b65a695a 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/IClickableMenuPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/IClickableMenuPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
 using StardewModdingAPI.Internal.Patching;
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/NpcPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/NpcPatcher.cs
index 5354f724..11f7ec69 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/NpcPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/NpcPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -20,7 +18,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         ** Fields
         *********/
         /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
-        private static IMonitor MonitorForGame;
+        private static IMonitor MonitorForGame = null!;
 
 
         /*********
@@ -56,7 +54,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="__result">The return value of the original method.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_CurrentDialogue(NPC __instance, ref Stack<Dialogue> __result, Exception __exception)
+        private static Exception? Finalize_CurrentDialogue(NPC __instance, ref Stack<Dialogue> __result, Exception? __exception)
         {
             if (__exception == null)
                 return null;
@@ -73,7 +71,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="__result">The patched method's return value.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_ParseMasterSchedule(string rawData, NPC __instance, ref Dictionary<int, SchedulePathDescription> __result, Exception __exception)
+        private static Exception? Finalize_ParseMasterSchedule(string rawData, NPC __instance, ref Dictionary<int, SchedulePathDescription> __result, Exception? __exception)
         {
             if (__exception != null)
             {
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/ObjectPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/ObjectPatcher.cs
index 499718b0..09a6fbbd 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/ObjectPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/ObjectPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -59,7 +57,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="__result">The patched method's return value.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_Object_loadDisplayName(ref string __result, Exception __exception)
+        private static Exception? Finalize_Object_loadDisplayName(ref string __result, Exception? __exception)
         {
             if (__exception is KeyNotFoundException)
             {
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/SaveGamePatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/SaveGamePatcher.cs
index 1941d2a8..490bbfb6 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/SaveGamePatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/SaveGamePatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -24,10 +22,10 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         ** Fields
         *********/
         /// <summary>Writes messages to the console and log file.</summary>
-        private static IMonitor Monitor;
+        private static IMonitor Monitor = null!;
 
         /// <summary>A callback invoked when custom content is removed from the save data to avoid a crash.</summary>
-        private static Action OnContentRemoved;
+        private static Action OnContentRemoved = null!;
 
 
         /*********
@@ -76,7 +74,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <summary>The method to call after <see cref="SaveGame.LoadFarmType"/> throws an exception.</summary>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_LoadFarmType(Exception __exception)
+        private static Exception? Finalize_LoadFarmType(Exception? __exception)
         {
             // missing custom farm type
             if (__exception?.Message.Contains("not a valid farm type") == true && !int.TryParse(SaveGame.loaded.whichFarm, out _))
@@ -110,7 +108,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <summary>Remove content which no longer exists in the game data.</summary>
         /// <param name="location">The current game location.</param>
         /// <param name="npcs">The NPC data.</param>
-        private static bool RemoveBrokenContent(GameLocation location, IDictionary<string, string> npcs)
+        private static bool RemoveBrokenContent(GameLocation? location, IDictionary<string, string> npcs)
         {
             bool removedAny = false;
             if (location == null)
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/SpriteBatchPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/SpriteBatchPatcher.cs
index b4c03bb9..d369e0ef 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/SpriteBatchPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/SpriteBatchPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
@@ -30,9 +28,9 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /*********
         ** Private methods
         *********/
-        /// <summary>The method to call after <see cref="SpriteBatch.CheckValid"/>.</summary>
+        /// <summary>The method to call after <see cref="SpriteBatch.CheckValid(Texture2D)"/>.</summary>
         /// <param name="texture">The texture to validate.</param>
-        private static void After_CheckValid(Texture2D texture)
+        private static void After_CheckValid(Texture2D? texture)
         {
             if (texture?.IsDisposed == true)
                 throw new ObjectDisposedException("Cannot draw this texture because it's disposed.");
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/UtilityPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/UtilityPatcher.cs
index 108ed585..6d75a581 100644
--- a/src/SMAPI.Mods.ErrorHandler/Patches/UtilityPatcher.cs
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/UtilityPatcher.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using HarmonyLib;
@@ -35,7 +33,7 @@ namespace StardewModdingAPI.Mods.ErrorHandler.Patches
         /// <param name="delimiter">The delimiter by which to split the text description.</param>
         /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
         /// <returns>Returns the exception to throw, if any.</returns>
-        private static Exception Finalize_GetItemFromStandardTextDescription(string description, char delimiter, ref Exception __exception)
+        private static Exception? Finalize_GetItemFromStandardTextDescription(string description, char delimiter, ref Exception? __exception)
         {
             return __exception != null
                 ? new FormatException($"Failed to parse item text description \"{description}\" with delimiter \"{delimiter}\".", __exception)
diff --git a/src/SMAPI.Mods.SaveBackup/ModEntry.cs b/src/SMAPI.Mods.SaveBackup/ModEntry.cs
index b2b41ca6..a79c092f 100644
--- a/src/SMAPI.Mods.SaveBackup/ModEntry.cs
+++ b/src/SMAPI.Mods.SaveBackup/ModEntry.cs
@@ -1,7 +1,6 @@
-#nullable disable
-
 using System;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
@@ -82,7 +81,7 @@ namespace StardewModdingAPI.Mods.SaveBackup
                 }
 
                 // compress backup if possible
-                if (!this.TryCompress(fallbackDir.FullName, targetFile, out Exception compressError))
+                if (!this.TryCompress(fallbackDir.FullName, targetFile, out Exception? compressError))
                 {
                     this.Monitor.Log(Constants.TargetPlatform != GamePlatform.Android
                         ? $"Backed up to {fallbackDir.FullName}." // expected to fail on Android
@@ -142,7 +141,7 @@ namespace StardewModdingAPI.Mods.SaveBackup
         /// <param name="destination">The destination file to create.</param>
         /// <param name="error">The error which occurred trying to compress, if applicable. This is <see cref="NotSupportedException"/> if compression isn't supported on this platform.</param>
         /// <returns>Returns whether compression succeeded.</returns>
-        private bool TryCompress(string sourcePath, FileInfo destination, out Exception error)
+        private bool TryCompress(string sourcePath, FileInfo destination, [NotNullWhen(false)] out Exception? error)
         {
             try
             {
@@ -210,7 +209,7 @@ namespace StardewModdingAPI.Mods.SaveBackup
         /// <param name="filter">A filter which matches the files or directories to copy, or <c>null</c> to copy everything.</param>
         /// <remarks>Derived from the SMAPI installer code.</remarks>
         /// <returns>Returns whether any files were copied.</returns>
-        private bool RecursiveCopy(FileSystemInfo source, DirectoryInfo targetFolder, Func<FileSystemInfo, bool> filter, bool copyRoot = true)
+        private bool RecursiveCopy(FileSystemInfo source, DirectoryInfo targetFolder, Func<FileSystemInfo, bool>? filter, bool copyRoot = true)
         {
             if (!source.Exists || filter?.Invoke(source) == false)
                 return false;
@@ -244,7 +243,7 @@ namespace StardewModdingAPI.Mods.SaveBackup
         private bool MatchSaveFolders(DirectoryInfo savesFolder, FileSystemInfo entry)
         {
             // only need to filter top-level entries
-            string parentPath = (entry as FileInfo)?.DirectoryName ?? (entry as DirectoryInfo)?.Parent?.FullName;
+            string? parentPath = (entry as FileInfo)?.DirectoryName ?? (entry as DirectoryInfo)?.Parent?.FullName;
             if (parentPath != savesFolder.FullName)
                 return true;