From b67f6ec7100b2c50f120723b1d1597125baa92dc Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Thu, 14 Mar 2019 13:18:06 -0700
Subject: [PATCH] Display actual and expected diagnostic messages when they
 dont match

---
 src/harness/fakes.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/harness/fakes.ts b/src/harness/fakes.ts
index 57e3722f64d..dcc125698c8 100644
--- a/src/harness/fakes.ts
+++ b/src/harness/fakes.ts
@@ -476,7 +476,9 @@ namespace fakes {
         assertDiagnosticMessages(...expectedDiagnostics: ExpectedDiagnostic[]) {
             const actual = this.diagnostics.slice().map(d => d.messageText as string);
             const expected = expectedDiagnostics.map(expectedDiagnosticToText);
-            assert.deepEqual(actual, expected, "Diagnostic arrays did not match");
+            assert.deepEqual(actual, expected, `Diagnostic arrays did not match:
+Actual: ${JSON.stringify(actual, /*replacer*/ undefined, " ")}
+Expected: ${JSON.stringify(expected, /*replacer*/ undefined, " ")}`);
         }
 
         printDiagnostics(header = "== Diagnostics ==") {