show simplified stack trace for deprecation notices

3 files changed, 57 insertions, 9 deletions

diff --git a/docs/release-notes.md b/docs/release-notes.md
index fed92d8d..01ba6e30 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -57,6 +57,7 @@ the C# mod that loads them is updated.
   * Added `helper.Content.ParseAssetName` to get an `IAssetName` for an arbitrary asset key.
   * If an asset is loaded multiple times in the same tick, `IAssetLoader.CanLoad` and `IAssetEditor.CanEdit` are now cached unless invalidated by `helper.Content.InvalidateCache`.
   * The `ISemanticVersion` comparison methods (`CompareTo`, `IsBetween`, `IsNewerThan`, and `IsOlderThan`) now allow null values. A null version is always considered older than any non-null version per [best practices](https://docs.microsoft.com/en-us/dotnet/api/system.icomparable-1.compareto#remarks).
+  * Deprecation notices now show a shorter stack trace in most cases, so it's clearer where the deprecated code is in the mod.
 * Fixes:
   * Fixed the `SDate` constructor being case-sensitive.
   * Fixed support for using locale codes from custom languages in asset names (e.g. `Data/Achievements.eo-EU`).
diff --git a/src/SMAPI/Framework/DeprecationManager.cs b/src/SMAPI/Framework/DeprecationManager.cs
index c80fdce7..37a5c8ef 100644
--- a/src/SMAPI/Framework/DeprecationManager.cs
+++ b/src/SMAPI/Framework/DeprecationManager.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Text;
 
 namespace StardewModdingAPI.Framework
 {
@@ -62,7 +63,8 @@ namespace StardewModdingAPI.Framework
                 return;
 
             // queue warning
-            this.QueuedWarnings.Add(new DeprecationWarning(source, nounPhrase, version, severity, new StackTrace(skipFrames: 1)));
+            var stack = new StackTrace(skipFrames: 1); // skip this method
+            this.QueuedWarnings.Add(new DeprecationWarning(source, nounPhrase, version, severity, stack));
         }
 
         /// <summary>A placeholder method used to track deprecated code for which a separate warning will be shown.</summary>
@@ -100,11 +102,11 @@ namespace StardewModdingAPI.Framework
 
                 // log message
                 if (level == LogLevel.Trace)
-                    this.Monitor.Log($"{message}\n{warning.StackTrace}", level);
+                    this.Monitor.Log($"{message}\n{this.GetSimplifiedStackTrace(warning.StackTrace, warning.Mod)}", level);
                 else
                 {
                     this.Monitor.Log(message, level);
-                    this.Monitor.Log(warning.StackTrace.ToString(), LogLevel.Debug);
+                    this.Monitor.Log(this.GetSimplifiedStackTrace(warning.StackTrace, warning.Mod), LogLevel.Debug);
                 }
             }
 
@@ -128,5 +130,42 @@ namespace StardewModdingAPI.Framework
             this.LoggedDeprecations.Add(key);
             return true;
         }
+
+        /// <summary>Get the simplest stack trace which shows where in the mod the deprecated code was called from.</summary>
+        /// <param name="stack">The stack trace.</param>
+        /// <param name="mod">The mod for which to show a stack trace.</param>
+        private string GetSimplifiedStackTrace(StackTrace stack, IModMetadata? mod)
+        {
+            // unknown mod, show entire stack trace
+            if (mod == null)
+                return stack.ToString();
+
+            // get frame info
+            var frames = stack
+                .GetFrames()
+                .Select(frame => (Frame: frame, Mod: this.ModRegistry.GetFrom(frame)))
+                .ToArray();
+            var modIds = new HashSet<string>(
+                from frame in frames
+                let id = frame.Mod?.Manifest.UniqueID
+                where id != null
+                select id
+            );
+
+            // can't filter to the target mod
+            if (modIds.Count != 1 || !modIds.Contains(mod.Manifest.UniqueID))
+                return stack.ToString();
+
+            // get stack frames for the target mod, plus one for context
+            var framesStartingAtMod = frames.SkipWhile(p => p.Mod == null).ToArray();
+            var displayFrames = framesStartingAtMod.TakeWhile(p => p.Mod != null).ToArray();
+            displayFrames = displayFrames.Concat(framesStartingAtMod.Skip(displayFrames.Length).Take(1)).ToArray();
+
+            // build stack trace
+            StringBuilder str = new();
+            foreach (var frame in displayFrames)
+                str.Append(new StackTrace(frame.Frame));
+            return str.ToString().TrimEnd();
+        }
     }
 }
diff --git a/src/SMAPI/Framework/ModRegistry.cs b/src/SMAPI/Framework/ModRegistry.cs
index de16a780..449dccb1 100644
--- a/src/SMAPI/Framework/ModRegistry.cs
+++ b/src/SMAPI/Framework/ModRegistry.cs
@@ -59,7 +59,7 @@ namespace StardewModdingAPI.Framework
 
         /// <summary>Get metadata for a loaded mod.</summary>
         /// <param name="uniqueID">The mod's unique ID.</param>
-        /// <returns>Returns the matching mod's metadata, or <c>null</c> if not found.</returns>
+        /// <returns>Returns the mod's metadata, or <c>null</c> if not found.</returns>
         public IModMetadata? Get(string uniqueID)
         {
             // normalize search ID
@@ -73,7 +73,7 @@ namespace StardewModdingAPI.Framework
 
         /// <summary>Get the mod metadata from one of its assemblies.</summary>
         /// <param name="type">The type to check.</param>
-        /// <returns>Returns the mod name, or <c>null</c> if the type isn't part of a known mod.</returns>
+        /// <returns>Returns the mod's metadata, or <c>null</c> if the type isn't part of a known mod.</returns>
         public IModMetadata? GetFrom(Type? type)
         {
             // null
@@ -89,8 +89,17 @@ namespace StardewModdingAPI.Framework
             return null;
         }
 
-        /// <summary>Get the friendly name for the closest assembly registered as a source of deprecation warnings.</summary>
-        /// <returns>Returns the source name, or <c>null</c> if no registered assemblies were found.</returns>
+        /// <summary>Get the mod metadata from a stack frame, if any.</summary>
+        /// <param name="frame">The stack frame to check.</param>
+        /// <returns>Returns the mod's metadata, or <c>null</c> if the frame isn't part of a known mod.</returns>
+        public IModMetadata? GetFrom(StackFrame frame)
+        {
+            MethodBase? method = frame.GetMethod();
+            return this.GetFrom(method?.ReflectedType);
+        }
+
+        /// <summary>Get the mod metadata from the closest assembly registered as a source of deprecation warnings.</summary>
+        /// <returns>Returns the mod's metadata, or <c>null</c> if no registered assemblies were found.</returns>
         public IModMetadata? GetFromStack()
         {
             // get stack frames
@@ -100,8 +109,7 @@ namespace StardewModdingAPI.Framework
             // search stack for a source assembly
             foreach (StackFrame frame in frames)
             {
-                MethodBase? method = frame.GetMethod();
-                IModMetadata? mod = this.GetFrom(method?.ReflectedType);
+                IModMetadata? mod = this.GetFrom(frame);
                 if (mod != null)
                     return mod;
             }