fix(commonjs): add classBodyDepth flag (#1507)

packages/commonjs/src/transform-commonjs.js

@@ -76,6 +76,7 @@ export default async function transformCommonjs(
   let scope = attachScopes(ast, 'scope');
   let lexicalDepth = 0;
   let programDepth = 0;
+  let classBodyDepth = 0;
   let currentTryBlockEnd = null;
   let shouldWrap = false;
 
@@ -258,6 +259,9 @@ export default async function transformCommonjs(
           }
           return;
         }
+        case 'ClassBody':
+          classBodyDepth += 1;
+          return;
         case 'ConditionalExpression':
         case 'IfStatement':
           // skip dead branches
@@ -354,7 +358,7 @@ export default async function transformCommonjs(
           return;
         case 'ThisExpression':
           // rewrite top-level `this` as `commonjsHelpers.commonjsGlobal`
-          if (lexicalDepth === 0) {
+          if (lexicalDepth === 0 && !classBodyDepth) {
             uses.global = true;
             if (!ignoreGlobal) {
               replacedGlobal.push(node);
@@ -405,6 +409,7 @@ export default async function transformCommonjs(
       programDepth -= 1;
       if (node.scope) scope = scope.parent;
       if (functionType.test(node.type)) lexicalDepth -= 1;
+      if (node.type === 'ClassBody') classBodyDepth -= 1;
     }
   });
 

packages/commonjs/test/fixtures/function/this/foo.js

@@ -1,5 +1,17 @@
-module.exports = function augmentThis() {
+exports.augmentThis = function augmentThis() {
   this.x = 'x';
 };
 
 this.y = 'y';
+
+exports.classThis = class classThis {
+  constructor(){
+    class _classThis {
+      y = 'yyy'
+      yyy = this.y
+    }
+    this._instance = new _classThis()
+  }
+  y = 'yy'
+  yy = this.y
+}

packages/commonjs/test/fixtures/function/this/main.js

@@ -1,7 +1,12 @@
-const foo = require('./foo');
+const { augmentThis, classThis } = require('./foo');
 
 const obj = {};
-foo.call(obj);
+augmentThis.call(obj);
 
 t.is(obj.x, 'x');
 t.is(this.y, 'y');
+
+const instance = new classThis();
+
+t.is(instance.yy,'yy');
+t.is(instance._instance.yyy,'yyy');

packages/commonjs/test/snapshots/function.js.md

@@ -7269,20 +7269,39 @@ Generated by [AVA](https://avajs.dev).
       ␊
       var main = {};␊
       ␊
-      var foo$1 = function augmentThis() {␊
+      var foo = {};␊
+      ␊
+      foo.augmentThis = function augmentThis() {␊
         this.x = 'x';␊
       };␊
       ␊
       commonjsGlobal.y = 'y';␊
       ␊
-      const foo = foo$1;␊
+      foo.classThis = class classThis {␊
+        constructor(){␊
+          class _classThis {␊
+            y = 'yyy'␊
+            yyy = this.y␊
+          }␊
+          this._instance = new _classThis();␊
+        }␊
+        y = 'yy'␊
+        yy = this.y␊
+      };␊
+      ␊
+      const { augmentThis, classThis } = foo;␊
       ␊
       const obj = {};␊
-      foo.call(obj);␊
+      augmentThis.call(obj);␊
       ␊
       t.is(obj.x, 'x');␊
       t.is(commonjsGlobal.y, 'y');␊
       ␊
+      const instance = new classThis();␊
+      ␊
+      t.is(instance.yy,'yy');␊
+      t.is(instance._instance.yyy,'yyy');␊
+      ␊
       module.exports = main;␊
       `,
     }