fix: minify infinity in expressions (#841)

* fix: minify infinity in expressions

* fix object expressions transformations

* address review comments

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

@@ -0,0 +1,12 @@
+function foo() {
+  let [Infinity] = some();
+  return Infinity;
+}
+
+function bar() {
+  let [...Infinity] = some();
+}
+
+function baz() {
+  let { inf = Infinity } = some();
+}

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

@@ -0,0 +1,14 @@
+function foo() {
+  let [Infinity] = some();
+  return Infinity;
+}
+
+function bar() {
+  let [...Infinity] = some();
+}
+
+function baz() {
+  let {
+    inf = 1 / 0
+  } = some();
+}

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

@@ -0,0 +1,10 @@
+let x = [Infinity, Infinity];
+
+let y = [
+  {
+    a: Infinity
+  },
+  {
+    a: Infinity
+  }
+];

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

@@ -0,0 +1,6 @@
+let x = [1 / 0, 1 / 0];
+let y = [{
+  a: 1 / 0
+}, {
+  a: 1 / 0
+}];

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

@@ -28,7 +28,14 @@ module.exports = function({ types: t }) {
           return;
         }
 
-        if (path.isLVal() && !path.parentPath.isExpressionStatement()) {
+        const bindingIds = path.parentPath.getBindingIdentifierPaths();
+
+        if (
+          bindingIds["Infinity"] === path &&
+          // ObjectProperty is common for ObjectExpression and ObjectPattern and only
+          // one of them is a Binding, the other is simply a reference
+          !path.parentPath.parentPath.isObjectExpression()
+        ) {
           return;
         }