From 0183acc6822ad5f13e20a690418e0b1707a33d82 Mon Sep 17 00:00:00 2001
From: Steve Gravrock <sdg@panix.com>
Date: Wed, 4 Jun 2025 18:04:40 -0700
Subject: [PATCH] Fix diff building when only one side has a custom object
 formatter

Fixes #2061
---
 lib/jasmine-core/jasmine.js           |  5 ++-
 spec/core/matchers/DiffBuilderSpec.js | 57 +++++++++++++++++++++++++++
 src/core/matchers/DiffBuilder.js      |  5 ++-
 3 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 21f95b05..493d01c3 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -4881,7 +4881,10 @@ getJasmineRequireObj().DiffBuilder = function(j$) {
         );
 
         if (useCustom) {
-          messages.push(wrapPrettyPrinted(actualCustom, expectedCustom, path));
+          const prettyActual = actualCustom || this.prettyPrinter_(actual);
+          const prettyExpected =
+            expectedCustom || this.prettyPrinter_(expected);
+          messages.push(wrapPrettyPrinted(prettyActual, prettyExpected, path));
           return false; // don't recurse further
         }
 
diff --git a/spec/core/matchers/DiffBuilderSpec.js b/spec/core/matchers/DiffBuilderSpec.js
index b15d0e2c..f134f214 100644
--- a/spec/core/matchers/DiffBuilderSpec.js
+++ b/spec/core/matchers/DiffBuilderSpec.js
@@ -161,6 +161,63 @@ describe('DiffBuilder', function() {
     expect(diffBuilder.getMessage()).toEqual(expectedMsg);
   });
 
+  it('handles cases where only the expected has a custom object formatter', function() {
+    const formatter = function(x) {
+      if (typeof x === 'number') {
+        return '[number:' + x + ']';
+      }
+    };
+    const prettyPrinter = jasmineUnderTest.makePrettyPrinter([formatter]);
+    const diffBuilder = new jasmineUnderTest.DiffBuilder({
+      prettyPrinter: prettyPrinter
+    });
+
+    diffBuilder.setRoots('five', 4);
+    diffBuilder.recordMismatch();
+
+    expect(diffBuilder.getMessage()).toEqual(
+      "Expected 'five' to equal [number:4]."
+    );
+  });
+
+  it('handles cases where only the actual has a custom object formatter', function() {
+    const formatter = function(x) {
+      if (typeof x === 'number') {
+        return '[number:' + x + ']';
+      }
+    };
+    const prettyPrinter = jasmineUnderTest.makePrettyPrinter([formatter]);
+    const diffBuilder = new jasmineUnderTest.DiffBuilder({
+      prettyPrinter: prettyPrinter
+    });
+
+    diffBuilder.setRoots(5, 'four');
+    diffBuilder.recordMismatch();
+
+    expect(diffBuilder.getMessage()).toEqual(
+      "Expected [number:5] to equal 'four'."
+    );
+  });
+
+  it('handles complex cases where only one side has a custom object formatter', function() {
+    const formatter = function(x) {
+      if (typeof x === 'number') {
+        return '[number:' + x + ']';
+      }
+    };
+    const prettyPrinter = jasmineUnderTest.makePrettyPrinter([formatter]);
+    const diffBuilder = new jasmineUnderTest.DiffBuilder({
+      prettyPrinter: prettyPrinter
+    });
+
+    diffBuilder.setRoots(5, { foo: 'bar', fnord: { graults: ['wombat'] } });
+    diffBuilder.recordMismatch();
+
+    expect(diffBuilder.getMessage()).toEqual(
+      "Expected [number:5] to equal Object({ foo: 'bar', fnord: Object({ graults: [ 'wombat' ] }) })."
+    );
+  });
+
   it('builds diffs involving asymmetric equality testers that implement valuesForDiff_ at the root', function() {
     const prettyPrinter = jasmineUnderTest.makePrettyPrinter([]),
       diffBuilder = new jasmineUnderTest.DiffBuilder({
diff --git a/src/core/matchers/DiffBuilder.js b/src/core/matchers/DiffBuilder.js
index 8a6da6a4..b68a91f4 100644
--- a/src/core/matchers/DiffBuilder.js
+++ b/src/core/matchers/DiffBuilder.js
@@ -37,7 +37,10 @@ getJasmineRequireObj().DiffBuilder = function(j$) {
         );
 
         if (useCustom) {
-          messages.push(wrapPrettyPrinted(actualCustom, expectedCustom, path));
+          const prettyActual = actualCustom || this.prettyPrinter_(actual);
+          const prettyExpected =
+            expectedCustom || this.prettyPrinter_(expected);
+          messages.push(wrapPrettyPrinted(prettyActual, prettyExpected, path));
           return false; // don't recurse further
         }