Improve code quality and write tests

node_modules/@babel/helper-simple-access/lib/index.js

@@ -0,0 +1,85 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = simplifyAccess;
+
+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; } }
+
+function simplifyAccess(path, bindingNames) {
+  path.traverse(simpleAssignmentVisitor, {
+    scope: path.scope,
+    bindingNames,
+    seen: new WeakSet()
+  });
+}
+
+const simpleAssignmentVisitor = {
+  UpdateExpression: {
+    exit(path) {
+      const {
+        scope,
+        bindingNames
+      } = this;
+      const arg = path.get("argument");
+      if (!arg.isIdentifier()) return;
+      const localName = arg.node.name;
+      if (!bindingNames.has(localName)) return;
+
+      if (scope.getBinding(localName) !== path.scope.getBinding(localName)) {
+        return;
+      }
+
+      if (path.parentPath.isExpressionStatement() && !path.isCompletionRecord()) {
+        const operator = path.node.operator == "++" ? "+=" : "-=";
+        path.replaceWith(t().assignmentExpression(operator, arg.node, t().numericLiteral(1)));
+      } else if (path.node.prefix) {
+        path.replaceWith(t().assignmentExpression("=", t().identifier(localName), t().binaryExpression(path.node.operator[0], t().unaryExpression("+", arg.node), t().numericLiteral(1))));
+      } else {
+        const old = path.scope.generateUidIdentifierBasedOnNode(arg.node, "old");
+        const varName = old.name;
+        path.scope.push({
+          id: old
+        });
+        const binary = t().binaryExpression(path.node.operator[0], t().identifier(varName), t().numericLiteral(1));
+        path.replaceWith(t().sequenceExpression([t().assignmentExpression("=", t().identifier(varName), t().unaryExpression("+", arg.node)), t().assignmentExpression("=", t().cloneNode(arg.node), binary), t().identifier(varName)]));
+      }
+    }
+
+  },
+  AssignmentExpression: {
+    exit(path) {
+      const {
+        scope,
+        seen,
+        bindingNames
+      } = this;
+      if (path.node.operator === "=") return;
+      if (seen.has(path.node)) return;
+      seen.add(path.node);
+      const left = path.get("left");
+      if (!left.isIdentifier()) return;
+      const localName = left.node.name;
+      if (!bindingNames.has(localName)) return;
+
+      if (scope.getBinding(localName) !== path.scope.getBinding(localName)) {
+        return;
+      }
+
+      path.node.right = t().binaryExpression(path.node.operator.slice(0, -1), t().cloneNode(path.node.left), path.node.right);
+      path.node.operator = "=";
+    }
+
+  }
+};