fix(cli): eszip error

apps/cli/src/next/commands/functions/deploy/deploy.integration.test.ts

@@ -1466,6 +1466,34 @@ describe("functions deploy", () => {
     }).pipe(Effect.ensuring(cleanupTempDir(tempDir)));
   });
 
+  it.live("fails with a contextual error when Docker bundling produces no eszip output", () => {
+    const tempDir = makeTempDir();
+    const child = mockChildProcessSpawner({ exitCode: 0 });
+
+    return Effect.gen(function* () {
+      yield* Effect.promise(() => writeProjectConfig(tempDir));
+      yield* Effect.promise(() => writeLocalFunction(tempDir, "hello-world"));
+
+      const { out, layer } = setup(tempDir, {
+        rawArgs: ["functions", "deploy", "hello-world", "--use-docker"],
+        childLayer: child.layer,
+      });
+
+      const error = yield* functionsDeploy({
+        ...BASE_FLAGS,
+        functionNames: ["hello-world"],
+        useDocker: true,
+      }).pipe(Effect.provide(layer), Effect.flip);
+
+      expect(error).toBeInstanceOf(Error);
+      if (error instanceof Error) {
+        expect(error.message).toContain("failed to open eszip:");
+        expect(error.message).toContain("output.eszip");
+      }
+      expect(out.stderrText).toContain("Bundling Function: hello-world\n");
+    }).pipe(Effect.ensuring(cleanupTempDir(tempDir)));
+  });
+
   it.live(
     "accepts nullable optional fields when listing remote functions for Docker deploys",
     () => {

apps/cli/src/shared/functions/deploy.ts

@@ -1404,7 +1404,13 @@ const bundleFunctionWithDocker = Effect.fnUntraced(function* (
       return yield* Effect.fail(new Error(`failed to bundle function: exit ${result.exitCode}`));
     }
 
-    const eszip = yield* Effect.tryPromise(() => readFile(outputPath));
+    const eszip = yield* Effect.tryPromise({
+      try: () => readFile(outputPath),
+      catch: (error) =>
+        new Error(
+          `failed to open eszip: ${error instanceof Error ? error.message : String(error)}`,
+        ),
+    });
     const compressed = new Uint8Array(
       Buffer.concat([
         Buffer.from(COMPRESSED_ESZIP_MAGIC),