PF previews show unchanged elements in collections

[VenelinMartinov]

When previewing a change in a resource using the Plugin Framework we incorrectly show all the unchanged elements in the collection. This offers a significantly worse experience than users get in TF with long collections:

Previewing update (test):
  pulumi:pulumi:Stack: (same)
    [urn=urn:pulumi:test::project::pulumi:pulumi:Stack::project-test]
    +-testprovider:index/test:Test: (replace)
        [id=test-id]
        [urn=urn:pulumi:test::project::testprovider:index/test:Test::p]
      ~ id  : "test-id" => output<string>
      ~ keys: [
            [0]: {
                    nested: "value0"
                }
            [1]: {
                    nested: "value1"
                }
            [2]: {
                    nested: "value2"
                }
            [3]: {
                    nested: "value3"
                }
            [4]: {
                    nested: "value4"
                }
            [5]: {
                    nested: "value5"
                }
            [6]: {
                    nested: "value6"
                }
            [7]: {
                    nested: "value7"
                }
            [8]: {
                    nested: "value8"
                }
            [9]: {
                    nested: "value9"
                }
            [10]: {
                    nested: "value10"
                }
            [11]: {
                    nested: "value11"
                }
            [12]: {
                    nested: "value12"
                }
            [13]: {
                    nested: "value13"
                }
            [14]: {
                    nested: "value14"
                }
            [15]: {
                    nested: "value15"
                }
            [16]: {
                    nested: "value16"
                }
            [17]: {
                    nested: "value17"
                }
            [18]: {
                    nested: "value18"
                }
            [19]: {
                    nested: "value19"
                }
          + [20]: {
                  + nested: "value20"
                }
        ]
Resources:
    +-1 to replace
    1 unchanged

versus

  # testprovider_test.res must be replaced
+/- resource "testprovider_test" "res" {
      ~ id = "test-id" -> (known after apply)

      + key { # forces replacement
          + nested = "value20"
        }

        # (20 unchanged blocks hidden)
    }

See TestDetailedDiffList/attribute_no_replace/long_list_added

[pulumi-bot]

This issue has been addressed in PR #2629 and shipped in release v3.97.0.