improve

packages/babel-helper-define-polyfill-provider/src/visitors/usage.ts

@@ -11,16 +11,71 @@ export default (
     return callProvider({ kind: "property", object, key, placement }, path);
   }
 
+  const polyfilled = new WeakSet();
+  function maybeMark(path: NodePath, oldNode: t.Node) {
+    if (path.node !== oldNode) {
+      polyfilled.add(path.node);
+    }
+  }
+
   return {
+    LogicalExpression: {
+      exit(path: NodePath<t.LogicalExpression>) {
+        const { node } = path;
+        if (node.operator !== "||") return;
+        if (polyfilled.has(node.left)) {
+          path.get("right").remove();
+        } else if (
+          t.isUnaryExpression(node.left) &&
+          node.left.operator === "!" &&
+          polyfilled.has(node.left.argument)
+        ) {
+          path.replaceWith(node.right);
+        }
+      },
+    },
+    IfStatement: {
+      exit(path: NodePath<t.IfStatement>) {
+        const { node } = path;
+        if (polyfilled.has(node.test)) {
+          path.replaceWith(node.consequent);
+        } else if (
+          t.isUnaryExpression(node.test) &&
+          node.test.operator === "!"
+        ) {
+          if (polyfilled.has(node.test.argument)) {
+            path.replaceWith(node.alternate);
+          }
+        }
+      },
+    },
+    ConditionalExpression: {
+      exit(path: NodePath<t.ConditionalExpression>) {
+        const { node } = path;
+        if (polyfilled.has(node.test)) {
+          path.replaceWith(node.consequent);
+        } else if (
+          t.isUnaryExpression(node.test) &&
+          node.test.operator === "!"
+        ) {
+          if (polyfilled.has(node.test.argument)) {
+            path.replaceWith(node.alternate);
+          }
+        }
+      },
+    },
     // Symbol(), new Promise
     ReferencedIdentifier(path: NodePath<t.Identifier>) {
       const {
         node: { name },
+        node,
         scope,
       } = path;
       if (scope.getBindingIdentifier(name)) return;
 
       callProvider({ kind: "global", name }, path);
+
+      maybeMark(path, node);
     },
 
     MemberExpression(path: NodePath<t.MemberExpression>) {
@@ -33,8 +88,12 @@ export default (
         if (binding && binding.path.isImportNamespaceSpecifier()) return;
       }
 
+      const { node } = path;
+
       const source = resolveSource(object);
-      return property(source.id, key, source.placement, path);
+      property(source.id, key, source.placement, path);
+
+      maybeMark(path, node);
     },
 
     ObjectPattern(path: NodePath<t.ObjectPattern>) {

packages/babel-plugin-polyfill-corejs3/test/fixtures/usage-pure/dead-branch/input.mjs

@@ -0,0 +1,17 @@
+String.prototype.padStart || err;
+!String.prototype.padStart || ok;
+
+
+String.prototype.padStart ? ok : err;
+!String.prototype.padStart ? err : ok;
+
+if (String.prototype.padStart) {
+  ok;
+} else {
+  err;
+}
+if (!String.prototype.padStart) {
+  err;
+} else {
+  ok;
+}

packages/babel-plugin-polyfill-corejs3/test/fixtures/usage-pure/dead-branch/options.json

@@ -0,0 +1,11 @@
+{
+  "plugins": [
+    [
+      "@@/polyfill-corejs3",
+      {
+        "method": "usage-pure",
+        "version": "3.34"
+      }
+    ]
+  ]
+}

packages/babel-plugin-polyfill-corejs3/test/fixtures/usage-pure/dead-branch/output.mjs

@@ -0,0 +1,11 @@
+import _padStartInstanceProperty from "core-js-pure/stable/instance/pad-start.js";
+_padStartInstanceProperty(String.prototype);
+ok;
+ok;
+ok;
+{
+  ok;
+}
+{
+  ok;
+}