How to mock Pulumi resources in Go unit tests?

Question content

I have a function that takes input from the aws openidconnectprovider pulumi resource and creates an iam role and attaches an include from that oidc provider The assumerolepolicy of the supplier's information.

Question: I'm trying to write a test for this function and mock the oidc provider as input to the function call. I can't figure out how to simulate it correctly so that the test output shows what I expect, currently it seems the simulated data isn't coming out as I expect.

Looks like I'm not using mocking correctly, but I'm giving up on the example here

More documentation here

package mypkg

import (
   "github.com/pulumi/pulumi-aws/sdk/v5/go/aws/iam"
   "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

func createmycustomrole(ctx *pulumi.context, name string, oidcprovider *iam.openidconnectprovider, opts ...pulumi.resourceoption) (*iam.role, error) {
    role := &iam.role{}

    componenturn := fmt.sprintf("%s-custom-role", name)

    err := ctx.registercomponentresource("pkg:aws:mycustomrole", componenturn, role, opts...)
    if err != nil {
        return nil, err
    }

    url := oidc.url.applyt(func(s string) string {
        return fmt.sprint(strings.replaceall(s, "https://", ""), ":sub")
    }).(pulumi.stringoutput)

    assumerolepolicy := pulumi.sprintf(`{
            "version": "2012-10-17",
            "statement": [{
                "effect": "allow",
                "principal": { "federated": "%s" },
                "action": "sts:assumerolewithwebidentity",
                "condition": {
                    "stringequals": {
                        "%s": [
                            "system:serviceaccount:kube-system:*",
                            "system:serviceaccount:kube-system:cluster-autoscaler"
                        ]
                    }
                }
            }]
        }`, oidcprovider.arn, url)

    roleurn := fmt.sprintf("%s-custom-role", name)

    role, err = iam.newrole(ctx, roleurn, &iam.roleargs{
            name:             pulumi.string(roleurn),
            description:      pulumi.string("create custom role"),
            assumerolepolicy: assumerolepolicy,
            tags:             pulumi.tostringmap(map[string]string{"project": "test"}),
        })
    if err != nil {
        return nil, err
    }

    return role, nil
}

package mypkg

import (
    "sync"
    "testing"

    "github.com/pulumi/pulumi-aws/sdk/v5/go/aws/iam"
    "github.com/pulumi/pulumi/sdk/v3/go/common/resource"
    "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
    "github.com/stretchr/testify/assert"
)

type mocks int

func (mocks) newresource(args pulumi.mockresourceargs) (string, resource.propertymap, error) {
    return args.name + "_id", args.inputs, nil
}

func (mocks) call(args pulumi.mockcallargs) (resource.propertymap, error) {
    outputs := map[string]interface{}{}
    if args.token == "aws:iam/getopenidconnectprovider:getopenidconnectprovider" {
        outputs["arn"] = "arn:aws:iam::123:oidc-provider/oidc.eks.us-west-2.amazonaws.com/id/abc"
        outputs["id"] = "abc"
        outputs["url"] = "https://someurl"
    }
    return resource.newpropertymapfrommap(outputs), nil
}

func testcreatemycustomrole(t *testing.t) {
    err := pulumi.runerr(func(ctx *pulumi.context) error {

        // gets the mocked oidc provider to use as input for the createdefaultautoscalerrole
        oidc, err := iam.getopenidconnectprovider(ctx, "get-test-oidc-provider", pulumi.id("abc"), &iam.openidconnectproviderstate{})
        assert.noerror(t, err)

        infra, err := createmycustomrole(ctx, "role1", oidc})
        assert.noerror(t, err)

        var wg sync.waitgroup
        wg.add(1)

        // check 1: assume role policy is formatted correctly
        pulumi.all(infra.urn(), infra.assumerolepolicy).applyt(func(all []interface{}) error {
            urn := all[0].(pulumi.urn)
            assumerolepolicy := all[1].(string)

            assert.equal(t, `{
            "version": "2012-10-17",
            "statement": [{
                "effect": "allow",
                "principal": { "federated": "arn:aws:iam::123:oidc-provider/oidc.eks.us-west-2.amazonaws.com/id/abc" },
                "action": "sts:assumerolewithwebidentity",
                "condition": {
                    "stringequals": {
                        "someurl:sub": [
                            "system:serviceaccount:kube-system:*",
                            "system:serviceaccount:kube-system:cluster-autoscaler"
                        ]
                    }
                }
            }]
        }`, assumerolepolicy)

            wg.done()
            return nil
        })

        wg.wait()
        return nil
    }, pulumi.withmocks("project", "stack", mocks(0)))
    assert.noerror(t, err)
}

output

diff:
                        --- expected
                        +++ actual
                        @@ -4,3 +4,3 @@
                                        "effect": "allow",
                        -               "principal": { "federated": "arn:aws:iam::123:oidc-provider/oidc.eks.us-west-2.amazonaws.com/id/abc" },
                        +               "principal": { "federated": "" },
                                        "action": "sts:assumerolewithwebidentity",
                        @@ -8,3 +8,3 @@
                                            "stringequals": {
                        -                       "someurl:sub": [
                        +                       ":sub": [
                                                    "system:serviceaccount:kube-system:*",
        test:           testcreatemycustomrole

Correct answer

It turns out that I used newresource wrong.

When getopenidconnectprovider is called in a test function, it reads the resource and creates a new resource output, triggering a call to mocks.newresource

The fix is ​​to use mock output to define an if statement in the newresource function call for the resource type returned by getopenidconnectprovider openidconnectprovider.

func (mocks) newresource(args pulumi.mockresourceargs) (string, resource.propertymap, error) {
    pulumi.printf(args.typetoken)
    outputs := args.inputs.mappable()
    if args.typetoken == "aws:iam/openidconnectprovider:openidconnectprovider" {
        outputs["arn"] = "arn:aws:iam::123:oidc-provider/oidc.eks.us-west-2.amazonaws.com/id/abc"
        outputs["id"] = "abc"
        outputs["url"] = "https://someurl"
    }
    return args.name + "_id", resource.newpropertymapfrommap(outputs), nil
}

func (mocks) call(args pulumi.mockcallargs) (resource.propertymap, error) {
    outputs := map[string]interface{}{}
    return resource.newpropertymapfrommap(outputs), nil
}

The code snippet below is where I changed assert so that it doesn't show the difference now compared to the changes made to newresource above

Diff:
                            --- Expected
                             Actual
                            @@ -8,3 +8,3 @@
                                                "StringEquals": {
                            -                       "b:sub": [
                            +                       "someurl:sub": [
                                                        "system:serviceaccount:kube-system:*",

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