Pulumi Infrastructure Troubleshooting Skill

Common Pulumi TypeScript Errors and Solutions

1. "This expression is not callable. Type 'never' has no call signatures"

Cause: TypeScript infers a type as never when working with Pulumi Outputs, especially with arrays.

Solution: Wrap the value in pulumi.output() and properly type the callback:

// ❌ Bad - TypeScript can't infer the type
value: pulumi.all(config.vpc.publicSubnets.map((s: any) => s.id))

// ✅ Good - Explicitly wrap and type
value: pulumi.output(config.vpc.publicSubnets).apply((subnets: any[]) =>
  pulumi.all(subnets.map((s: any) => s.id)).apply(ids => ids.join(","))
)