fix: skip flattening spread object with __proto__

packages/babel-plugin-transform-react-jsx/src/create-plugin.ts

@@ -39,6 +39,15 @@ const get = (pass: PluginPass, name: string) =>
 const set = (pass: PluginPass, name: string, v: any) =>
   pass.set(`@babel/plugin-react-jsx/${name}`, v);
 
+function hasProto(node: t.ObjectExpression) {
+  return node.properties.some(
+    value =>
+      t.isObjectProperty(value, { computed: false, shorthand: false }) &&
+      (t.isIdentifier(value.key, { name: "__proto__" }) ||
+        t.isStringLiteral(value.key, { value: "__proto__" })),
+  );
+}
+
 export interface Options {
   filter?: (node: t.Node, pass: PluginPass) => boolean;
   importSource?: string;
@@ -422,7 +431,7 @@ You can set \`throwIfNamespace: false\` to bypass this warning.`,
       if (t.isJSXSpreadAttribute(attribute.node)) {
         const arg = attribute.node.argument;
         // Collect properties into props array if spreading object expression
-        if (t.isObjectExpression(arg)) {
+        if (t.isObjectExpression(arg) && !hasProto(arg)) {
           array.push(...arg.properties);
         } else {
           array.push(t.spreadElement(arg));
@@ -718,7 +727,17 @@ You can set \`throwIfNamespace: false\` to bypass this warning.`,
           }
 
           if (objs.length === 1) {
-            return objs[0];
+            if (
+              !(
+                t.isSpreadElement(props[0]) &&
+                // If an object expression is spread element's argument
+                // it is very likely to contain __proto__ and we should stop
+                // optimizing spread element
+                t.isObjectExpression(props[0].argument)
+              )
+            ) {
+              return objs[0];
+            }
           }
 
           // looks like we have multiple objects
@@ -755,7 +774,12 @@ You can set \`throwIfNamespace: false\` to bypass this warning.`,
         accumulateAttribute(props, attr);
       }
 
-      return props.length === 1 && t.isSpreadElement(props[0])
+      return props.length === 1 &&
+        t.isSpreadElement(props[0]) &&
+        // If an object expression is spread element's argument
+        // it is very likely to contain __proto__ and we should stop
+        // optimizing spread element
+        !t.isObjectExpression(props[0].argument)
         ? props[0].argument
         : props.length > 0
         ? t.objectExpression(props)

packages/babel-plugin-transform-react-jsx/test/fixtures/react-automatic/flattens-spread/input.js

@@ -2,6 +2,10 @@
 
 <div {...props}>{contents}</div>;
 
-<img alt="" {...{src, title}} />;
+<img alt="" {...{src, title, __proto__}} />;
 
 <blockquote {...{cite}}>{items}</blockquote>;
+
+<pre {...{["__proto__"]: null }}></pre>;
+
+<code {...{[__proto__]: null }}></code>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react-automatic/flattens-spread/output.mjs

@@ -14,11 +14,22 @@ _jsx("div", { ...props,
 _jsx("img", {
   alt: "",
   src,
-  title
+  title,
+  __proto__
 });
 
 /*#__PURE__*/
 _jsx("blockquote", {
   cite,
   children: items
 });
+
+/*#__PURE__*/
+_jsx("pre", {
+  ["__proto__"]: null
+});
+
+/*#__PURE__*/
+_jsx("code", {
+  [__proto__]: null
+});

packages/babel-plugin-transform-react-jsx/test/fixtures/react-automatic/handle-spread-with-proto/input.js

@@ -0,0 +1,3 @@
+<p {...{__proto__: null}}>text</p>;
+
+<div {...{"__proto__": null}}>{contents}</div>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react-automatic/handle-spread-with-proto/output.mjs

@@ -0,0 +1,15 @@
+import { jsx as _jsx } from "react/jsx-runtime";
+
+/*#__PURE__*/
+_jsx("p", { ...{
+    __proto__: null
+  },
+  children: "text"
+});
+
+/*#__PURE__*/
+_jsx("div", { ...{
+    "__proto__": null
+  },
+  children: contents
+});

packages/babel-plugin-transform-react-jsx/test/fixtures/react/flattens-spread/input.js

@@ -2,6 +2,10 @@
 
 <div {...props}>{contents}</div>;
 
-<img alt="" {...{src, title}} />;
+<img alt="" {...{src, title, __proto__}} />;
 
 <blockquote {...{cite}}>{items}</blockquote>;
+
+<pre {...{["__proto__"]: null }}></pre>;
+
+<code {...{[__proto__]: null }}></code>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react/flattens-spread/output.js

@@ -8,10 +8,21 @@ React.createElement("div", props, contents);
 React.createElement("img", {
   alt: "",
   src,
-  title
+  title,
+  __proto__
 });
 
 /*#__PURE__*/
 React.createElement("blockquote", {
   cite
 }, items);
+
+/*#__PURE__*/
+React.createElement("pre", {
+  ["__proto__"]: null
+});
+
+/*#__PURE__*/
+React.createElement("code", {
+  [__proto__]: null
+});

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto-babel-7/input.js

@@ -0,0 +1,3 @@
+<p {...{__proto__: null}}>text</p>;
+
+<div {...{"__proto__": null}}>{contents}</div>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto-babel-7/options.json

@@ -0,0 +1,3 @@
+{
+  "BABEL_8_BREAKING": false
+}

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto-babel-7/output.js

@@ -0,0 +1,9 @@
+/*#__PURE__*/
+React.createElement("p", babelHelpers.extends({
+  __proto__: null
+}), "text");
+
+/*#__PURE__*/
+React.createElement("div", babelHelpers.extends({
+  "__proto__": null
+}), contents);

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto/input.js

@@ -0,0 +1,3 @@
+<p {...{__proto__: null}}>text</p>;
+
+<div {...{"__proto__": null}}>{contents}</div>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto/options.json

@@ -0,0 +1,3 @@
+{
+  "BABEL_8_BREAKING": true
+}

packages/babel-plugin-transform-react-jsx/test/fixtures/react/handle-spread-with-proto/output.js

@@ -0,0 +1,11 @@
+/*#__PURE__*/
+React.createElement("p", { ...{
+    __proto__: null
+  }
+}, "text");
+
+/*#__PURE__*/
+React.createElement("div", { ...{
+    "__proto__": null
+  }
+}, contents);

packages/babel-plugin-transform-react-jsx/test/fixtures/react/proto-in-jsx-attribute/input.js

@@ -0,0 +1 @@
+<p __proto__={null} class="bar">text</p>;

packages/babel-plugin-transform-react-jsx/test/fixtures/react/proto-in-jsx-attribute/output.js

@@ -0,0 +1,5 @@
+/*#__PURE__*/
+React.createElement("p", {
+  __proto__: null,
+  class: "bar"
+}, "text");