fix: Make babel-plugin-minify-infinity work again. (#839)

packages/babel-plugin-minify-infinity/__tests__/fixtures/fn-param/actual.js

@@ -1,3 +1,4 @@
 function a(Infinity) {}
 function b(...Infinity) {}
 function c({ Infinity }) {}
+function d([Infinity]) {}

packages/babel-plugin-minify-infinity/__tests__/fixtures/fn-param/expected.js

@@ -4,4 +4,6 @@ function b(...Infinity) {}
 
 function c({
   Infinity
-}) {}
+}) {}
+
+function d([Infinity]) {}

packages/babel-plugin-minify-infinity/__tests__/fixtures/to-1-over-0/actual.js

@@ -1 +1,8 @@
 Infinity;
+[Infinity];
+let infobj = {inf: Infinity};
+func(Infinity);
+1/Infinity;
+let inf = Infinity;
+while (Infinity) break;
+inf = Infinity;

packages/babel-plugin-minify-infinity/__tests__/fixtures/to-1-over-0/expected.js

@@ -1 +1,12 @@
-1 / 0;
+1 / 0;
+[1 / 0];
+let infobj = {
+  inf: 1 / 0
+};
+func(1 / 0);
+1 / (1 / 0);
+let inf = 1 / 0;
+
+while (1 / 0) break;
+
+inf = 1 / 0;

packages/babel-plugin-minify-infinity/src/index.js

@@ -6,11 +6,18 @@ module.exports = function({ types: t }) {
     t.numericLiteral(1),
     t.numericLiteral(0)
   );
+  const badTransforms = {
+    ArrayPattern: () => true,
+    AssignmentExpression: path => path.container.left === path.node,
+    ObjectProperty: path => path.container.shorthand,
+    RestElement: () => true
+  };
   return {
     name: "minify-infinity",
     visitor: {
       // Infinity -> 1 / 0
       Identifier(path) {
+        path.isLVal();
         if (path.node.name !== "Infinity") {
           return;
         }
@@ -28,7 +35,10 @@ module.exports = function({ types: t }) {
           return;
         }
 
-        if (path.isLVal() && !path.parentPath.isExpressionStatement()) {
+        if (
+          path.isLVal() &&
+          (badTransforms[path.parentPath.type] || (() => false))(path)
+        ) {
           return;
         }