Enable escape and once tests (#4618)

test/escape.test.js

@@ -0,0 +1,30 @@
+import assert from 'assert';
+import lodashStable from 'lodash';
+import escape from '../escape.js';
+import unescape from '../unescape.js';
+
+describe('escape', function() {
+  var escaped = '&<>"'/',
+      unescaped = '&<>"\'/';
+
+  escaped += escaped;
+  unescaped += unescaped;
+
+  it('should escape values', function() {
+    assert.strictEqual(escape(unescaped), escaped);
+  });
+
+  it('should handle strings with nothing to escape', function() {
+    assert.strictEqual(escape('abc'), 'abc');
+  });
+
+  it('should escape the same characters unescaped by `_.unescape`', function() {
+    assert.strictEqual(escape(unescape(escaped)), escaped);
+  });
+
+  lodashStable.each(['`', '/'], function(chr) {
+    it('should not escape the "' + chr + '" character', function() {
+      assert.strictEqual(escape(chr), chr);
+    });
+  });
+});