Pulumi (Typescript) Unit Testing: `pulumi.Config()` returns empty object under test

Question

I am using mocha to unit test my pulumi code. I was able to test and mock my resources by injecting a custom pulumi.runtime.Mocks.

However, when I start using pulumi.Config() with some required fields, pulumi while under test does not read my config files. Some resources are instantiated and configure from index.ts.

How I am checking is calling const config = new pulumi.Config(), and seeing if my config shows up.

I tried the following:

• setting pulumi.runtime.setAllConfig globally, returned an empty config object.
• adding getConfig function into pulumi.runtime.Mocks, returned an empty config object.
• using pulumi.runtime.setConfig for individual config items within before(), returned an empty config object.

I have no idea what to do.

---

Here is a simplified example of my issue

// index.ts
import * as aws from "@pulumi/aws";

const config = new pulumi.Config();
const env = config.require("env");
const region = config.require("region");

const userData = `#!/bin/bash echo "Hello, World!" > index.html nohup python -m SimpleHTTPServer 80 &`;

export const server = new aws.ec2.Instance("web-server-www", {
  instanceType: "t2.micro",
  securityGroups: [group.name], // reference the group object above
  ami: "ami-c55673a0", // AMI for us-east-2 (Ohio)
  userData: userData, // start a simple webserver
  tags: { Name: "www-server", env: env, region: region }, // name tag

});

// test.ts
import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";
import * as mocha from "mocha";

// Mocks for Pulumi configuration
class MyMock implements pulumi.runtime.Mocks {
  public newResource(args: pulumi.runtime.MockResourceArgs): { id: string; state: any } {
    return {
      id: args.inputs.name + "_id",
      state: args.inputs,
    };
  }

  public call(args: pulumi.runtime.MockCallArgs): Record<string, any> {
    return {};
  }

  public getConfig(key: string): string {
    const config: { [key: string]: string } = {
      env: "dev",
      region: "us-west-2",
    };

    return config[key];
  }
}

// Sets the mocks for the Pulumi runtime
pulumi.runtime.setAllConfig({env:"dev", region:"us-west-2"}) // config object is empty

// Function to read and log configuration
function getConfig() {
    const config = new pulumi.Config();
    const env = config.require("env");
    const region = config.require("region");
}

describe("Infrastructure", function () {
  let infra: typeof import("./index");

  before(async function () {
    // It's important to import the program _after_ the mocks are defined.
    getConfig() // config object is empty
    pulumi.runtime.setConfig("env","dev")
    pulumi.runtime.setConfig("region","us-west-2") // config object is empty
    infra = await import("./index");
    const config = pulumi.Config() // where I am checking if configs are loaded
  });

  describe("#server", function () {
    // check 1: Instances have a Name tag.
    it("must have a name tag", function (done) {
      pulumi.all([infra.server.urn, infra.server.tags]).apply(([urn, tags]) => {
        if (!tags || !tags["Name"]) {
          done(new Error(`Missing a name tag on server ${urn}`));
        } else {
          done();
        }
      });
    });
  });
});