What class type should I pass to Pulumi arguments to make it work?

Question

I'm trying to pass the tags as a custom object class to Pulumi as an argument because I can set the Name property on a needed basis. The problem is that it doesn't work. Due to the lack of JS/TS knowledge, I don't understand what it wants from me.

Could anyone give me a clue?

import * as aws from "@pulumi/aws";

class Common_tags_test {
  
  Name!: string;
  Owner: string = 'test';
  ManagedBy: string =  'Pulumi';

  constructor() {}

  set_name(name: string) {
    this.Name = name
  }

}


// const common_tags = {
//   Owner: 'test',
//   ManagedBy: 'Pulumi'
// };

const main_vpc = new aws.ec2.Vpc("Test_VPC", {
  cidrBlock: "10.10.0.0/16",
  // tags: {...common_tags, ...{Name: 'Test_VPC'}}
  tags: new Common_tags_test()
});

Error:

    TSError: ⨯ Unable to compile TypeScript:
    index.ts(29,3): error TS2322: Type 'Common_tags_test' is not assignable to type '{ [key: string]: Input<string>; } | Promise<{ [key: string]: Input<string>; }> | OutputInstance<{ [key: string]: Input<string>; }> | undefined'.
      Type 'Common_tags_test' is not assignable to type '{ [key: string]: Input<string>; }'.
        Index signature is missing in type 'Common_tags_test'.
``

Answer 1

Because typescript allows for strongly typed properties, the tags property isn't expecting a type of Common_tags_test there.

You had the right idea before, doing something like

import * as aws from "@pulumi/aws";

const baseTags = {
    Owner: "test",
    ManagedBy: "Pulumi"
};

const vpc = new aws.ec2.Vpc("vpc", {
    tags: {
        ...baseTags,
        Name: "my-vpc"
    },
    cidrBlock: "10.10.0.0/"
})

If you really wanted to use a class you could do the following:

import * as aws from "@pulumi/aws";

class CommonTags {
  Name!: string;
  Owner: string = "test";
  ManagedBy: string = "Pulumi";

  constructor() {}

  setTags(name: string) :any {
      return {
          Name: name,
          Owner: this.Owner,
          ManagedBy: this.ManagedBy
      }
  }

}

let mytags = new CommonTags();

const vpc = new aws.ec2.Vpc("vpc", {
  tags: {
    ...mytags.setTags("My-VPC")
  },
  cidrBlock: "10.10.0.0/16",
});

Personally, I'd use the first way. It's still possible to re-use them by putting them in a module and sharing that.