`GeneratedFieldExplicitInputUxComponentSourceBase::validateComponentInput()` allows garbage to pile up

Could you please give an example for 'garbage value'?

Thanks @wim leers🙏. I just tested this using the 'Heading' SDC, by adding an extra property 'textUnwanted' when making a curl request to the endpoint /xb/api/v0/layout/xb_page/5 and the changes were successfully saved. There were no validation errors regarding the unexpected prop

curl --location 'https://starshot.ddev.site/xb/api/v0/layout/xb_page/5' \
--header 'accept: */*' \
--header 'accept-language: en-US,en-GB;q=0.9,en;q=0.8' \
--header 'content-type: application/json' \
--header 'origin: https://starshot.ddev.site' \
--header 'priority: u=1, i' \
--header 'referer: https://starshot.ddev.site/xb/xb_page/5/editor/component/fdc18261-ef6e-41bd-bdba-99ecc72bf359' \
--header 'sec-ch-ua: "Chromium";v="136", "Google Chrome";v="136", "Not.A/Brand";v="99"' \
--header 'sec-ch-ua-mobile: ?0' \
--header 'sec-ch-ua-platform: "Linux"' \
--header 'sec-fetch-dest: empty' \
--header 'sec-fetch-mode: cors' \
--header 'sec-fetch-site: same-origin' \
--header 'user-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36' \
--header 'x-csrf-token: PIqRn04kuCGgm5leY3w_pc0Oq9ZGv0mzWXds0SE7cmg' \
--header 'Cookie: SSESS1a128ff57fee5bd2b5663cea7bd52db5=n4epfmoesptq7m91dcj6skrvtl' \
--data '{
  "layout": [
    {
      "nodeType": "region",
      "id": "content",
      "name": "Content",
      "components": [
        {
          "slots": [],
          "nodeType": "component",
          "type": "sdc.experience_builder.heading",
          "uuid": "fdc18261-ef6e-41bd-bdba-99ecc72bf359"
        }
      ]
    }
  ],
  "model": {
    "fdc18261-ef6e-41bd-bdba-99ecc72bf359": {
      "name": "Heading",
      "resolved": {
        "text": "A heading element new text",
        "style": "primary",
        "element": "h1",
        "textUnwanted": "An unwanted heading" // ⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️Invalid prop
      },
      "source": {
        "text": {
          "expression": "ℹ︎string␟value",
          "sourceType": "static:field_item:string",
          "value": [
            {
              "value": "A heading element new text"
            }
          ]
        },
        "textUnwanted": { // ⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️Invalid prop
          "expression": "ℹ︎string␟value",
          "sourceType": "static:field_item:string",
          "value": [
            {
              "value": "An unwanted heading"
            }
          ]
        },
        "style": {
          "expression": "ℹ︎list_string␟value",
          "sourceType": "static:field_item:list_string",
          "value": [
            {
              "value": "primary"
            }
          ],
          "sourceTypeSettings": {
            "storage": {
              "allowed_values": [
                {
                  "value": "primary",
                  "label": "primary"
                },
                {
                  "value": "secondary",
                  "label": "secondary"
                }
              ]
            }
          }
        },
        "element": {
          "expression": "ℹ︎list_string␟value",
          "sourceType": "static:field_item:list_string",
          "value": [
            {
              "value": "h1"
            }
          ],
          "sourceTypeSettings": {
            "storage": {
              "allowed_values": [
                {
                  "value": "div",
                  "label": "div"
                },
                {
                  "value": "h1",
                  "label": "h1"
                },
                {
                  "value": "h2",
                  "label": "h2"
                },
                {
                  "value": "h3",
                  "label": "h3"
                },
                {
                  "value": "h4",
                  "label": "h4"
                },
                {
                  "value": "h5",
                  "label": "h5"
                },
                {
                  "value": "h6",
                  "label": "h6"
                }
              ]
            }
          }
        }
      }
    }
  },
  "entity_form_fields": {
    "langcode[0][value]": "en",
    "revision_log[0][value]": "",
    "title[0][value]": "Untitled page",
    "path[0][alias]": "",
    "path[0][source]": "/page/5",
    "path[0][langcode]": "en",
    "image[media_library_selection]": "",
    "description[0][value]": ""
  }
}'

Just to confirm, does this mean validateComponentInput() currently allows unexpected properties (i.e., garbage values) for SDCs?

Thanks @wim leers. I have updated GeneratedFieldExplicitInputUxComponentSourceBase::validateComponentInput() and added a check for unexpected props.

However, no exception was thrown for the curl request mentioned in #5, and the heading component was still added to the canvas. The expected error only appeared when publishing the page

Shouldn't the error have been thrown at the time of the request?

I also tried to validate 'missing' props but that resulted in many test failures as some props are not always part of user input (Like 'attribute' prop in sdc.experience_builder.my-hero component)

Updated the MR based on my review - but I'm wondering if we should just do GC on those properties in \Drupal\canvas\ComponentSource\ComponentSourceInterface::clientModelToInput instead rather than raise an Exception?

Added suggestions for expanding missing test coverage.

Looks good to me. The missing test coverage was already there ¿? Guess I overlooked it.

Fixed some logic for this to be reused by any other component source extending GeneratedFieldExplicitInputUxComponentSourceBase, even in contrib.