From cee393d0da6c845d809b3549103e51c66c585ab9 Mon Sep 17 00:00:00 2001
From: Pete Bacon Darwin <pete@bacondarwin.com>
Date: Sun, 27 Sep 2020 10:42:28 +0100
Subject: [PATCH] test(compiler-cli): improve error message if a unit test is
 bad (#38959)

The message now also reports the name of the predicate function
that failed.

PR Close #38959
---
 packages/compiler-cli/src/ngtsc/testing/src/utils.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/compiler-cli/src/ngtsc/testing/src/utils.ts b/packages/compiler-cli/src/ngtsc/testing/src/utils.ts
index f2c84d263d..d1597de5a6 100644
--- a/packages/compiler-cli/src/ngtsc/testing/src/utils.ts
+++ b/packages/compiler-cli/src/ngtsc/testing/src/utils.ts
@@ -60,7 +60,8 @@ export function getDeclaration<T extends ts.Declaration>(
     throw new Error(`No such symbol: ${name} in ${fileName}`);
   }
   if (!assert(chosenDecl)) {
-    throw new Error(`Symbol ${name} from ${fileName} is a ${ts.SyntaxKind[chosenDecl.kind]}`);
+    throw new Error(`Symbol ${name} from ${fileName} is a ${
+        ts.SyntaxKind[chosenDecl.kind]}. Expected it to pass predicate "${assert.name}()".`);
   }
   return chosenDecl;
 }