dont lift declarations when not intialized (fix #309) (#314)

babel · Dec 1, 2016 · b76482f · b76482f
1 parent bcb486c
commit b76482f
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/...gin-transform-merge-sibling-variables/__tests__/transform-merge-sibling-variables-test.js b/...gin-transform-merge-sibling-variables/__tests__/transform-merge-sibling-variables-test.js
@@ -135,6 +135,16 @@ describe("transform-merge-sibling-variables-plugin", () => {
     expect(transform(source)).toBe(source);
   });
 
+  it("dont lift when the declarations are not initialized", () => {
+    const source = unpad(`
+      for (var i = 0;;) {
+        var i;
+      }
+    `);
+
+    expect(transform(source)).toBe(source);
+  });
+
   it("dont lift when there are multiple declarations", () => {
     const source = unpad(`
       for (var i = 0; i < 0; i++) {

diff --git a/packages/babel-plugin-transform-merge-sibling-variables/src/index.js b/packages/babel-plugin-transform-merge-sibling-variables/src/index.js
@@ -15,7 +15,7 @@ module.exports = function({ types: t }) {
 
       let firstNode = body[0].node.declarations[0];
 
-      if (!t.isIdentifier(firstNode.id)) {
+      if (!t.isIdentifier(firstNode.id) || !firstNode.init) {
         return;
       }