3 files changed, 88 insertions, 0 deletions
diff --git a/std/_util/deep_assign.ts b/std/_util/deep_assign.ts
new file mode 100644
index 000000000..9034d89bd
--- /dev/null
+++ b/std/_util/deep_assign.ts
@@ -0,0 +1,34 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { assert } from "../testing/asserts.ts";
+
+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]: [string, unknown]): void => {
+      if (value instanceof Date) {
+        target[key] = new Date(value);
+        return;
+      }
+      if (!value || typeof value !== `object`) {
+        target[key] = value;
+        return;
+      }
+      if (Array.isArray(value)) {
+        target[key] = [];
+      }
+      // value is an Object
+      if (typeof target[key] !== `object` || !target[key]) {
+        target[key] = {};
+      }
+      assert(value);
+      deepAssign(target[key] as Record<string, unknown>, value);
+    });
+  }
+  return target;
+}
diff --git a/std/_util/deep_assign_test.ts b/std/_util/deep_assign_test.ts
new file mode 100644
index 000000000..f1a56e1ad
--- /dev/null
+++ b/std/_util/deep_assign_test.ts
@@ -0,0 +1,24 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+const { test } = Deno;
+import { assertEquals, assert } from "../testing/asserts.ts";
+import { deepAssign } from "./deep_assign.ts";
+
+test("deepAssignTest", function (): void {
+  const date = new Date("1979-05-27T07:32:00Z");
+  const reg = RegExp(/DENOWOWO/);
+  const obj1 = { deno: { bar: { deno: ["is", "not", "node"] } } };
+  const obj2 = { foo: { deno: date } };
+  const obj3 = { foo: { bar: "deno" }, reg: reg };
+  const actual = deepAssign(obj1, obj2, obj3);
+  const expected = {
+    foo: {
+      deno: new Date("1979-05-27T07:32:00Z"),
+      bar: "deno",
+    },
+    deno: { bar: { deno: ["is", "not", "node"] } },
+    reg: RegExp(/DENOWOWO/),
+  };
+  assert(date !== expected.foo.deno);
+  assert(reg !== expected.reg);
+  assertEquals(actual, expected);
+});
diff --git a/std/_util/has_own_property.ts b/std/_util/has_own_property.ts
new file mode 100644
index 000000000..351905cec
--- /dev/null
+++ b/std/_util/has_own_property.ts
@@ -0,0 +1,30 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+/**
+ * Determines whether an object has a property with the specified name.
+ * Avoid calling prototype builtin `hasOwnProperty` for two reasons:
+ *
+ * 1. `hasOwnProperty` is defined on the object as something else:
+ *
+ *      const options = {
+ *        ending: 'utf8',
+ *        hasOwnProperty: 'foo'
+ *      };
+ *      options.hasOwnProperty('ending') // throws a TypeError
+ *
+ * 2. The object doesn't inherit from `Object.prototype`:
+ *
+ *       const options = Object.create(null);
+ *       options.ending = 'utf8';
+ *       options.hasOwnProperty('ending'); // throws a TypeError
+ *
+ * @param obj A Object.
+ * @param v A property name.
+ * @see https://eslint.org/docs/rules/no-prototype-builtins
+ */
+export function hasOwnProperty<T>(obj: T, v: PropertyKey): boolean {
+  if (obj == null) {
+    return false;
+  }
+  return Object.prototype.hasOwnProperty.call(obj, v);
+}