branded.ts

type Output = string;
type Input = string;

interface SourceConfig {
  uuid: string;
  inputs: Input[];
  outputs: Output[];
}

type SourceInstanceId<T extends SourceConfig> = string & { config: T };
type Outputs<T extends SourceInstanceId<any>> = T['config']['outputs'];

function createSourceInstance<T extends SourceConfig>(input: T) {
  return {
    instanceId: JSON.stringify(['source1']) as SourceInstanceId<T>,
  };
}

function getOutputs<T extends SourceInstanceId<any>>(instanceId: T) {
  // code to retrieve outputs from hashmap
  return {
    outputs: [] as Outputs<T>,
  };
}

const config = {
  uuid: 'blah',
  inputs: ['input1', 'input2'],
  outputs: ['output1', 'output2'],
} as const satisfies SourceConfig;

const instance = createSourceInstance(config);
const { outputs } = getOutputs(instance.instanceId);
// Expected type of outputs is ['output1', 'output2']