From 5d293659a82eef68c9cbef604ae6279c59ee9654 Mon Sep 17 00:00:00 2001
From: Ned Twigg <ned.twigg@diffplug.com>
Date: Mon, 3 Jun 2024 16:30:07 -0700
Subject: [PATCH] Provide more debugging info when a snapshot gets set multiple
 times (improve #370).

---
 jvm/CHANGELOG.md                                           | 1 +
 .../kotlin/com/diffplug/selfie/guts/WriteTracker.kt        | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/jvm/CHANGELOG.md b/jvm/CHANGELOG.md
index 027089b6..96ee2c32 100644
--- a/jvm/CHANGELOG.md
+++ b/jvm/CHANGELOG.md
@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bump Kotlin to 2.0.0. ([#405](https://github.com/diffplug/selfie/pull/405))
 ### Fixed
 - Do not remove stale snapshot files when readonly is true. ([#367](https://github.com/diffplug/selfie/pull/367))
+- Provide more debugging info when a snapshot gets set multiple times. (helps with [#370](https://github.com/diffplug/selfie/issues/370))
 
 ## [2.0.2] - 2024-03-20
 ### Fixed
diff --git a/jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/guts/WriteTracker.kt b/jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/guts/WriteTracker.kt
index 428b65ab..ebec0955 100644
--- a/jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/guts/WriteTracker.kt
+++ b/jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/guts/WriteTracker.kt
@@ -85,7 +85,12 @@ sealed class WriteTracker<K : Comparable<K>, V> {
         }
     if (existing.snapshot != snapshot) {
       throw layout.fs.assertFailed(
-          "Snapshot was set to multiple values!\n  first time: ${existing.callStack.location.ideLink(layout)}\n   this time: ${call.location.ideLink(layout)}\n$howToFix",
+          "Snapshot was set to multiple values!\n" +
+              "  first value: ${existing.snapshot}\n" +
+              "    this time: ${snapshot}\n" +
+              "   first call: ${existing.callStack.ideLink(layout)}\n" +
+              "    this call: ${call.ideLink(layout)}\n" +
+              "$howToFix",
           existing.snapshot,
           snapshot)
     } else if (!layout.allowMultipleEquivalentWritesToOneLocation) {