Improve code quality and write tests

node_modules/@babel/helper-annotate-as-pure/lib/index.js

@@ -0,0 +1,34 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = annotateAsPure;
+
+function t() {
+  const data = _interopRequireWildcard(require("@babel/types"));
+
+  t = function () {
+    return data;
+  };
+
+  return data;
+}
+
+function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) { var desc = Object.defineProperty && Object.getOwnPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : {}; if (desc.get || desc.set) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } } newObj.default = obj; return newObj; } }
+
+const PURE_ANNOTATION = "#__PURE__";
+
+const isPureAnnotated = ({
+  leadingComments
+}) => !!leadingComments && leadingComments.some(comment => /[@#]__PURE__/.test(comment.value));
+
+function annotateAsPure(pathOrNode) {
+  const node = pathOrNode.node || pathOrNode;
+
+  if (isPureAnnotated(node)) {
+    return;
+  }
+
+  t().addComment(node, "leading", PURE_ANNOTATION);
+}