handle unwrapping `require` in any expression (#3292)

2 files changed, 89 insertions, 5 deletions

diff --git a/src/js_parser.zig b/src/js_parser.zig
index b844aa9b4..7c227ce75 100644
--- a/src/js_parser.zig
+++ b/src/js_parser.zig
@@ -308,7 +308,8 @@ const ExportsStringName = "exports";
 const TransposeState = struct {
     is_await_target: bool = false,
     is_then_catch_target: bool = false,
-    loc: logger.Loc,
+    is_require_immediately_assigned_to_decl: bool = false,
+    loc: logger.Loc = logger.Loc.Empty,
 };
 
 var true_args = &[_]Expr{
@@ -2248,6 +2249,10 @@ const ExprIn = struct {
     // isn't something real-world code would do but it matters for conformance
     // tests.
     assign_target: js_ast.AssignTarget = js_ast.AssignTarget.none,
+
+    // Currently this is only used when unwrapping a call to `require()`
+    // with `__toESM()`.
+    is_immediately_assigned_to_decl: bool = false,
 };
 
 const ExprOut = struct {
@@ -5102,7 +5107,7 @@ fn NewParser_(
             return state;
         }
 
-        pub fn transposeRequire(p: *P, arg: Expr, _: anytype) Expr {
+        pub fn transposeRequire(p: *P, arg: Expr, state: anytype) Expr {
             switch (arg.data) {
                 .e_string => |str| {
 
@@ -5146,6 +5151,13 @@ fn NewParser_(
                         p.import_items_for_namespace.put(p.allocator, namespace_ref, ImportItemForNamespaceMap.init(p.allocator)) catch unreachable;
                         p.ignoreUsage(p.require_ref);
                         p.recordUsage(namespace_ref);
+
+                        if (!state.is_require_immediately_assigned_to_decl) {
+                            return p.newExpr(E.Identifier{
+                                .ref = namespace_ref,
+                            }, arg.loc);
+                        }
+
                         return p.newExpr(
                             E.RequireString{
                                 .import_record_index = import_record_index,
@@ -16453,15 +16465,18 @@ fn NewParser_(
                         // error from the unbundled require() call failing.
                         if (e_.args.len == 1) {
                             const first = e_.args.first_();
+                            const state = TransposeState{
+                                .is_require_immediately_assigned_to_decl = in.is_immediately_assigned_to_decl and first.data == .e_string,
+                            };
                             switch (first.data) {
                                 .e_string => {
                                     // require(FOO) => require(FOO)
-                                    return p.transposeRequire(first, null);
+                                    return p.transposeRequire(first, state);
                                 },
                                 .e_if => {
                                     // require(FOO  ? '123' : '456') => FOO ? require('123') : require('456')
                                     // This makes static analysis later easier
-                                    return p.require_transposer.maybeTransposeIf(first, null);
+                                    return p.require_transposer.maybeTransposeIf(first, state);
                                 },
                                 else => {},
                             }
@@ -18936,7 +18951,12 @@ fn NewParser_(
                         }
                     }
 
-                    decl.value = p.visitExpr(val);
+                    if (only_scan_imports_and_do_not_visit) {
+                        @compileError("only_scan_imports_and_do_not_visit must not run this.");
+                    }
+                    decl.value = p.visitExprInOut(val, .{
+                        .is_immediately_assigned_to_decl = true,
+                    });
 
                     if (comptime FeatureFlags.unwrap_commonjs_to_esm) {
                         if (prev_require_to_convert_count < p.imports_to_convert_from_require.items.len) {
diff --git a/test/bundler/bundler_cjs2esm.test.ts b/test/bundler/bundler_cjs2esm.test.ts
index 2c498a4c6..01a17356b 100644
--- a/test/bundler/bundler_cjs2esm.test.ts
+++ b/test/bundler/bundler_cjs2esm.test.ts
@@ -3,6 +3,19 @@ import dedent from "dedent";
 import { itBundled, testForFile } from "./expectBundled";
 var { describe, test, expect } = testForFile(import.meta.path);
 
+const fakeReactNodeModules = {
+  "/node_modules/react/index.js": /* js */ `
+    module.exports = { react: "react" }
+  `,
+  "/node_modules/react/package.json": /* json */ `
+    {
+      "name": "react",
+      "version": "2.0.0",
+      "main": "index.js"
+    }
+  `,
+};
+
 describe("bundler", () => {
   itBundled("cjs2esm/ModuleExportsFunction", {
     files: {
@@ -222,4 +235,55 @@ describe("bundler", () => {
       stdout: "development",
     },
   });
+  itBundled("cjs2esm/UnwrappedModuleRequireAssigned", {
+    files: {
+      "/entry.js": /* js */ `
+        const react = require("react");
+        console.log(react.react);
+        
+        const react1 = (console.log(require("react").react), require("react"));
+        console.log(react1.react);
+        
+        const react2 = (require("react"), console.log(require("react").react));
+        console.log(react2);
+        
+        let x = {};
+        x.react = require("react");
+        console.log(x.react.react);
+        
+        console.log(require("react").react);
+        
+        let y = {};
+        y[require("react")] = require("react");
+        console.log(y[require("react")].react);
+
+        let r = require("react");
+        console.log(r.react);
+        r = require("react");
+        console.log(r.react);
+
+        let n = 1;
+        n = require("react");
+        console.log(n.react);
+
+        let m = 1,
+          o = require("react");
+        console.log(m, o.react);
+
+        let h = Math.random() > 0.5;
+        let p = require(h ? "react" : "react");
+        console.log(p.react);
+
+        console.log(require(h ? "react" : "react").react);
+      `,
+      ...fakeReactNodeModules,
+    },
+    onAfterBundle: api => {
+      const code = api.readFile("out.js");
+      expect(code).toContain("__toESM(");
+    },
+    run: {
+      stdout: "react\nreact\nreact\nreact\nundefined\nreact\nreact\nreact\nreact\nreact\nreact\n1 react\nreact\nreact",
+    },
+  });
 });