fix(bundle): use node-style CJS interop for the Deno platform (#34533)

`deno bundle` (with the default `--platform=deno`) miscompiled imports
of dual CJS/ESM packages whose ESM entry default-imports a CJS entry that
sets `module.exports.__esModule = true`. `tslib`'s `modules/index.js` is
the canonical example. The resulting bundle threw at module-init time
with `TypeError: Cannot destructure property '__extends' of
'import_tslib.default' as it is undefined`, even though the same code
runs fine under both `node` and `deno run`. 

Fixes #34524.

Author: bartlomieju

cli/tools/bundle/mod.rs

@@ -687,6 +687,33 @@ var __require = __deno_internal_createRequire(import.meta.url);
   }
 }
 
+// Force esbuild's CommonJS-to-ESM interop helper (`__toESM`) into "node mode"
+// for the Deno platform.
+//
+// esbuild emits a node-mode interop call (`__toESM(require_x(), 1)`) only when
+// it can tell the importing module is *explicitly* ESM (a `.mjs`/`.mts` file or
+// a file under a `"type": "module"` package.json). It learns this while walking
+// package.json during its own resolve step. In `deno bundle` resolution and
+// loading are handled by our plugin, and esbuild's plugin protocol has no way
+// to communicate a module's type, so esbuild falls back to browser-mode interop
+// which respects the `__esModule` marker and does not synthesize `.default`.
+//
+// For packages whose ESM wrapper default-imports a CJS entry that sets
+// `module.exports.__esModule = true` (e.g. tslib's `modules/index.js`), that
+// means `import_x.default` ends up undefined and module init throws. Deno's own
+// runtime always uses node-style interop here, so the bundle should too. We
+// rewrite the helper's `<isNodeMode> || !mod || !mod.__esModule` condition to
+// always pick the node-mode branch. See denoland/deno#34524.
+//
+// The variable names differ between minified and non-minified output, but the
+// `.__esModule` access and surrounding shape are stable, so a single regex
+// covers both.
+fn force_node_cjs_interop(contents: &str) -> String {
+  let re =
+    lazy_regex::regex!(r#"\w+\s*\|\|\s*!\w+\s*\|\|\s*!\w+\.__esModule\s*\?"#);
+  re.replace(contents, "1 ?").into_owned()
+}
+
 fn format_location(
   location: &esbuild_client::protocol::Location,
   current_dir: &Path,
@@ -2024,7 +2051,7 @@ pub fn maybe_process_contents(
   if is_js {
     let string = str::from_utf8(&file.contents)?;
     let string = if should_replace_require_shim {
-      replace_require_shim(string, minified)
+      force_node_cjs_interop(&replace_require_shim(string, minified))
     } else {
       string.to_string()
     };

tests/specs/bundle/cjs_esm_default_interop/__test__.jsonc

@@ -0,0 +1,35 @@
+{
+  // Regression test for https://github.com/denoland/deno/issues/34524
+  //
+  // A dual CJS/ESM package whose ESM entry default-imports a CJS entry that
+  // sets `module.exports.__esModule = true` (the shape tslib ships). The
+  // bundle must use node-style CJS interop so the default import is the whole
+  // `module.exports`, matching how `deno run` executes the same files.
+  "tempDir": true,
+  "tests": {
+    "bundle": {
+      "steps": [
+        {
+          "args": "bundle --quiet -o out.js entry.mjs",
+          "output": "[WILDCARD]"
+        },
+        {
+          "args": "run -A out.js",
+          "output": "out.out"
+        }
+      ]
+    },
+    "bundle_minified": {
+      "steps": [
+        {
+          "args": "bundle --quiet --minify -o out.min.js entry.mjs",
+          "output": "[WILDCARD]"
+        },
+        {
+          "args": "run -A out.min.js",
+          "output": "out.out"
+        }
+      ]
+    }
+  }
+}

tests/specs/bundle/cjs_esm_default_interop/entry.mjs

@@ -0,0 +1,3 @@
+import * as pkg from "dual-pkg";
+console.log("foo:", typeof pkg.foo);
+console.log("bar:", typeof pkg.bar);

tests/specs/bundle/cjs_esm_default_interop/node_modules/dual-pkg/cjs.js

@@ -0,0 +1,2 @@
+foo: function
+bar: function

tests/specs/bundle/cjs_esm_default_interop/node_modules/dual-pkg/modules/index.js

@@ -0,0 +1 @@
+{}

tests/specs/bundle/cjs_esm_default_interop/node_modules/dual-pkg/modules/package.json

@@ -20,7 +20,7 @@ var __toESM = (mod, isNodeMode, target) => (target = mod != null ? __create(__ge
   // file that has been converted to a CommonJS file using a Babel-
   // compatible transform (i.e. "__esModule" has not been set), then set
   // "default" to the CommonJS "module.exports" for node compatibility.
-  isNodeMode || !mod || !mod.__esModule ? __defProp(target, "default", { value: mod, enumerable: true }) : target,
+  1 ? __defProp(target, "default", { value: mod, enumerable: true }) : target,
   mod
 ));