PF investigate support for PlanModifiers

[VenelinMartinov]

What happened?

Looking at the code around PF Diff it doesn't look like PlanModifiers are used in ProposedNew anywhere - does that mean we ignore these?

Example

"vlan_id": schema.StringAttribute{
	MarkdownDescription: `VLAN ID`,
	Computed:            true,
	Optional:            true,
	PlanModifiers: []planmodifier.String{
		stringplanmodifier.UseStateForUnknown(),
	},
},

This should yield a different plan then when the PlanModifier is missing.

Output of pulumi about

.

Additional context

No response

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[t0yv0]

I expect plan modifiers to fully work, curious if you find a counter-example.

[corymhall]

I think that pulumi/pulumi-aws#4273 is an example of this in pulumi-aws

[VenelinMartinov]

I think I have a repro: #2217

I'm assuming this is connected to #2218 and will investigate as part of that.

[VenelinMartinov]

Not 100% sure about this anymore - tried to repro in pulumi-random:

"""A Python Pulumi program"""

import pulumi
import pulumi_random as random


resNumeric = random.RandomString(
    "str1",
    length=10,
    numeric=False,
)

resNumber = random.RandomString(
    "str2",
    length=10,
    number=False,
)

pulumi.export("number val 1", resNumeric.number)
pulumi.export("numeric val 1", resNumeric.numeric)

pulumi.export("number val 2", resNumber.number)
pulumi.export("numeric val 2", resNumber.numeric)

These properties have plan modifiers and they seem to be working: https://github.com/hashicorp/terraform-provider-random/blame/455294a2038f3cf39a31f8eda231b95f190df250/internal/provider/resource_string.go#L453

The above program outputs False, False, False, False

[corymhall]

I can't reproduce the AWS issue anymore either if I use the latest bridge@master so something must have been fixed (I can reproduce on latest aws which is on [email protected])

[VenelinMartinov]

This turned out to be a red herring - the test was set up wrong - plan modifiers are applied fine as long as the provider is implemented correctly to apply the plan, not the config:

#2217 will add a regression test here.