chore: Implement strict mode (denoland/deno_std#453)

Original: https://github.com/denoland/deno_std/commit/be24677d15494e83eea2e99bfc5ccfdde31cb892

2 files changed, 7 insertions, 4 deletions

diff --git a/util/async.ts b/util/async.ts
index 15edb1b42..b737c4cc8 100644
--- a/util/async.ts
+++ b/util/async.ts
@@ -25,7 +25,7 @@ export function deferred<T>(): Deferred<T> {
       methods = { resolve, reject };
     }
   );
-  return Object.assign(promise, methods) as Deferred<T>;
+  return Object.assign(promise, methods)! as Deferred<T>;
 }
 
 interface TaggedYieldedValue<T> {
diff --git a/util/deep_assign.ts b/util/deep_assign.ts
index 77bf5e9b3..1dfc00a5b 100644
--- a/util/deep_assign.ts
+++ b/util/deep_assign.ts
@@ -1,12 +1,15 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-export function deepAssign(target: object, ...sources: object[]): object {
+export function deepAssign(
+  target: Record<string, unknown>,
+  ...sources: object[]
+): object | undefined {
   for (let i = 0; i < sources.length; i++) {
     const source = sources[i];
     if (!source || typeof source !== `object`) {
       return;
     }
     Object.entries(source).forEach(
-      ([key, value]): void => {
+      ([key, value]: [string, unknown]): void => {
         if (value instanceof Date) {
           target[key] = new Date(value);
           return;
@@ -22,7 +25,7 @@ export function deepAssign(target: object, ...sources: object[]): object {
         if (typeof target[key] !== `object` || !target[key]) {
           target[key] = {};
         }
-        deepAssign(target[key], value);
+        deepAssign(target[key] as Record<string, unknown>, value!);
       }
     );
   }