2 files changed, 14 insertions, 4 deletions
diff --git a/std/testing/format.ts b/std/testing/format.ts
index 953347c27..62fdde5eb 100644
--- a/std/testing/format.ts
+++ b/std/testing/format.ts
@@ -1,3 +1,5 @@
+import { assert } from "./asserts.ts";
+
 // This file is ported from pretty-format@24.0.0
 /**
  * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
@@ -361,7 +363,9 @@ const getKeysOfEnumerableProperties = (object: {}): Array<string | symbol> => {
 
   if (Object.getOwnPropertySymbols) {
     Object.getOwnPropertySymbols(object).forEach((symbol): void => {
-      if (Object.getOwnPropertyDescriptor(object, symbol)!.enumerable) {
+      const d = Object.getOwnPropertyDescriptor(object, symbol);
+      assert(d != null);
+      if (d.enumerable) {
         keys.push(symbol);
       }
     });
diff --git a/std/testing/mod.ts b/std/testing/mod.ts
index 16eae5ebe..a60e9c93f 100644
--- a/std/testing/mod.ts
+++ b/std/testing/mod.ts
@@ -261,11 +261,14 @@ function printResults(
 }
 
 function previousPrinted(name: string, results: TestResults): boolean {
-  const curIndex: number = results.keys.get(name)!;
+  const curIndex = results.keys.get(name);
+  assert(curIndex != null);
   if (curIndex === 0) {
     return true;
   }
-  return results.cases.get(curIndex - 1)!.printed;
+  const prev = results.cases.get(curIndex - 1);
+  assert(prev != null);
+  return prev.printed;
 }
 
 async function createTestCase(
@@ -274,7 +277,10 @@ async function createTestCase(
   exitOnFail: boolean,
   { fn, name }: TestDefinition
 ): Promise<void> {
-  const result: TestResult = results.cases.get(results.keys.get(name)!)!;
+  const i = results.keys.get(name);
+  assert(i != null);
+  const result = results.cases.get(i);
+  assert(result != null);
   try {
     const start = performance.now();
     await fn();