add yes/no comments to describe what we're actually testing for in types.isReferenced

lib/6to5/types/index.js

@@ -234,22 +234,30 @@ t.prependToMemberExpression = function (member, append) {
  */
 
 t.isReferenced = function (node, parent) {
+  // yes: { [NODE]: "" }
   if (t.isProperty(parent)) {
     return parent.key === node && parent.computed;
   }
 
+  // no: function foo(...NODE) {}
   if (t.isRestElement(parent)) {
     return false;
   }
 
+  // no: [NODE = foo] = [];
+  // yes: [foo = NODE] = [];
   if (t.isAssignmentPattern(parent)) {
     return parent.right !== node;
   }
 
+  // no: [NODE] = [];
+  // no: ({ NODE }) = [];
   if (t.isPattern(parent)) {
     return false;
   }
 
+  // no: function NODE() {}
+  // no: function foo(NODE) {}
   if (t.isFunction(parent)) {
     for (var i = 0; i < parent.params.length; i++) {
       var param = parent.params[i];
@@ -259,38 +267,49 @@ t.isReferenced = function (node, parent) {
     return parent.id !== node;
   }
 
+  // no: class NODE {}
   if (t.isClass(parent)) {
     return parent.id !== node;
   }
 
+  // yes: class { [NODE](){} }
   if (t.isMethodDefinition(parent)) {
     return parent.key === node && parent.computed;
   }
 
+  // no: import NODE from "bar";
   if (t.isImportSpecifier(parent)) {
     return false;
   }
 
+  // no: import * as NODE from "foo";
   if (t.isImportBatchSpecifier(parent)) {
     return false;
   }
 
+  // no: NODE: for (;;) {}
   if (t.isLabeledStatement(parent)) {
     return false;
   }
 
+  // no: try {} catch (NODE) {}
   if (t.isCatchClause(parent)) {
     return parent.param !== node;
   }
 
+  // no: var NODE = init;
+  // yes: var id = NODE;
   if (t.isVariableDeclarator(parent)) {
     return parent.id !== node;
   }
 
+  // yes: PARENT[NODE]
+  // yes: NODE.child
+  // no: parent.CHILD
   if (t.isMemberExpression(parent)) {
-    if (parent.property === node && parent.computed) { // PARENT[NODE]
+    if (parent.property === node && parent.computed) {
       return true;
-    } else if (parent.object === node) { // NODE.child
+    } else if (parent.object === node) {
       return true;
     } else {
       return false;