replace jest with ava

node_modules/ava/lib/context-ref.js

@@ -0,0 +1,42 @@
+'use strict';
+const clone = require('lodash/clone');
+
+class ContextRef {
+	constructor() {
+		this.value = {};
+	}
+
+	get() {
+		return this.value;
+	}
+
+	set(newValue) {
+		this.value = newValue;
+	}
+
+	copy() {
+		return new LateBinding(this);
+	}
+}
+module.exports = ContextRef;
+
+class LateBinding extends ContextRef {
+	constructor(ref) {
+		super();
+		this.ref = ref;
+		this.bound = false;
+	}
+
+	get() {
+		if (!this.bound) {
+			this.set(clone(this.ref.get()));
+		}
+
+		return super.get();
+	}
+
+	set(newValue) {
+		this.bound = true;
+		super.set(newValue);
+	}
+}