fix: emit when bundle contains single module (#4042)

Fixes #4031

When a bundle contains a single module, we were incorrectly determining
the module name, resulting in a non-functional bundle.  This PR corrects
that determination.

1 files changed, 2 insertions, 0 deletions

diff --git a/cli/tests/subdir/single_module.ts b/cli/tests/subdir/single_module.ts
new file mode 100644
index 000000000..1cd2cd781
--- /dev/null
+++ b/cli/tests/subdir/single_module.ts
@@ -0,0 +1,2 @@
+console.log("Hello world!");
+export {};