add createClass displayName to react

lib/6to5/transformers/react.js

@@ -0,0 +1,63 @@
+var b = require("recast").types.builders;
+var _ = require("lodash");
+
+var addDisplayName = function (id, call) {
+  if (!call || call.type !== "CallExpression") return;
+
+  var callee = call.callee;
+  if (callee.type !== "MemberExpression") return;
+
+  // not React
+  var obj = callee.object;
+  if (obj.type !== "Identifier" || obj.name !== "React") return;
+
+  // not createClass
+  var prop = callee.property;
+  if (prop.type !== "Identifier" || prop.name !== "createClass") return;
+
+  // no arguments
+  var args = call.arguments;
+  if (args.length !== 1) return;
+
+  // not an object
+  var first = args[0];
+  if (first.type !== "ObjectExpression") return;
+
+  var props = first.properties;
+  var safe = true;
+
+  _.each(props, function (prop) {
+    if (prop.key.name === "displayName") {
+      return safe = false;
+    }
+  });
+
+  if (safe) {
+    props.unshift(b.property("init", b.identifier("displayName"), b.literal(id)));
+  }
+};
+
+exports.AssignmentExpression =
+exports.Property =
+exports.VariableDeclarator = function (node) {
+  var left, right;
+
+  if (node.type === "AssignmentExpression") {
+    left = node.left;
+    right = node.right;
+  } else if (node.type === "Property") {
+    left = node.key;
+    right = node.value;
+  } else if (node.type === "VariableDeclarator") {
+    left = node.id;
+    right = node.init;
+  }
+
+  if (left && left.type === "MemberExpression") {
+    left = left.property;
+  }
+
+  if (left && left.type === "Identifier") {
+    addDisplayName(left.name, right);
+  }
+};