Fix bug that breaks `bunx prisma init` when node is not installed (#3362)

* tweak cjs

* Handle more cases, add a test

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

3 files changed, 56 insertions, 2 deletions

diff --git a/src/js_parser.zig b/src/js_parser.zig
index 5a9bca91a..51627a134 100644
--- a/src/js_parser.zig
+++ b/src/js_parser.zig
@@ -3425,10 +3425,43 @@ pub const Parser = struct {
                 .esm => {
                     exports_kind = .esm;
                 },
-                else => {
-                    exports_kind = .esm;
+                .unknown => {
+                    // Divergence from esbuild and Node.js: we default to ESM
+                    // when there are no exports.
+                    //
+                    // However, this breaks certain packages.
+                    // For example, the checkpoint-client used by
+                    // Prisma does an eval("__dirname") but does not export
+                    // anything.
+                    //
+                    // If they use an import statement, we say it's ESM because that's not allowed in CommonJS files.
+                    const uses_any_import_statements = brk: {
+                        for (p.import_records.items) |*import_record| {
+                            if (import_record.is_internal or import_record.is_unused) continue;
+                            if (import_record.kind == .stmt) break :brk true;
+                        }
+
+                        break :brk false;
+                    };
+
+                    if (uses_any_import_statements) {
+                        exports_kind = .esm;
+
+                        // Otherwise, if they use CommonJS features its CommonJS
+                    } else if (p.symbols.items[p.require_ref.innerIndex()].use_count_estimate > 0 or uses_dirname or uses_filename) {
+                        exports_kind = .cjs;
+                    } else {
+                        // If unknown, we default to ESM
+                        exports_kind = .esm;
+                    }
                 },
             }
+
+            if (exports_kind == .cjs and p.options.features.commonjs_at_runtime) {
+                wrapper_expr = .{
+                    .bun_js = {},
+                };
+            }
         }
 
         if (exports_kind == .esm and p.commonjs_named_exports.count() > 0 and !p.unwrap_all_requires and !force_esm) {
diff --git a/test/cli/run/commonjs-no-export.test.ts b/test/cli/run/commonjs-no-export.test.ts
new file mode 100644
index 000000000..b0bedd9d6
--- /dev/null
+++ b/test/cli/run/commonjs-no-export.test.ts
@@ -0,0 +1,14 @@
+import { test, expect } from "bun:test";
+import { bunEnv, bunExe } from "harness";
+import { join } from "path";
+
+test("CommonJS entry point with no exports", () => {
+  const { stdout, exitCode } = Bun.spawnSync({
+    cmd: [bunExe(), "run", "--bun", join(import.meta.dir, "commonjs-no-exports-fixture.js")],
+    env: bunEnv,
+    stderr: "inherit",
+  });
+
+  expect(stdout.toString().trim().endsWith("--pass--")).toBe(true);
+  expect(exitCode).toBe(0);
+});
diff --git a/test/cli/run/commonjs-no-exports-fixture.js b/test/cli/run/commonjs-no-exports-fixture.js
new file mode 100644
index 000000000..12458c3de
--- /dev/null
+++ b/test/cli/run/commonjs-no-exports-fixture.js
@@ -0,0 +1,7 @@
+// see https://www.npmjs.com/package/checkpoint-client
+require("node:fs");
+
+eval("__dirname");
+eval("__filename");
+
+console.log("--pass--");