feat: Object.ensurePlainObject util

Author: medikoo

object/ensure-plain-object.js

@@ -0,0 +1,9 @@
+"use strict";
+
+var safeToString  = require("../safe-to-string")
+  , isPlainObject = require("./is-plain-object");
+
+module.exports = function (value) {
+	if (!isPlainObject(value)) throw new TypeError(safeToString(value) + " is not a plain object");
+	return value;
+};

object/index.js

@@ -16,6 +16,7 @@ module.exports = {
 	ensureNaturalNumber: require("./ensure-natural-number"),
 	ensureNaturalNumberValue: require("./ensure-natural-number-value"),
 	ensurePlainFunction: require("./ensure-plain-function"),
+	ensurePlainObject: require("./ensure-plain-object"),
 	ensurePromise: require("./ensure-promise"),
 	ensureThenable: require("./ensure-thenable"),
 	entries: require("./entries"),

test/object/ensure-plain-object.js

@@ -0,0 +1,16 @@
+"use strict";
+
+module.exports = function (t, a) {
+	// Just sanity checks, as logic is tested at isPlainFunction
+	var obj = {};
+	a(t(obj), obj, "Reguar object instance");
+	obj = Object.create(null);
+	a(t(obj), obj, "Null prototype");
+	a.throws(
+		function () {
+			t(function () {});
+		},
+		TypeError,
+		"Error"
+	);
+};