# lists.canJoin

> Check whether two adjacent list sequences can be joined.



- Member path: `doc.lists.canJoin(…)`
- Mutates document: no
- Idempotency: `idempotent`
- Supports tracked mode: no
- Supports dry run: no

## Expected result

Returns a ListsCanJoinResult indicating feasibility and reason if not possible.

## Input schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$defs": {
    "ListItemAddress": {
      "type": "object",
      "properties": {
        "kind": {
          "const": "block"
        },
        "nodeType": {
          "const": "listItem"
        },
        "nodeId": {
          "type": "string"
        },
        "story": {
          "$ref": "#/$defs/StoryLocator"
        }
      },
      "additionalProperties": false,
      "required": [
        "kind",
        "nodeType",
        "nodeId"
      ]
    },
    "StoryLocator": {
      "description": "Story scope. Defaults to document body when omitted. Use {kind:'story', storyType:'body'} for body, or other storyType values for headers, footers, footnotes, endnotes.",
      "oneOf": [
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "body"
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType"
          ]
        },
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "headerFooterSlot"
            },
            "section": {
              "$ref": "#/$defs/SectionAddress"
            },
            "headerFooterKind": {
              "enum": [
                "header",
                "footer"
              ]
            },
            "variant": {
              "enum": [
                "default",
                "first",
                "even"
              ]
            },
            "resolution": {
              "enum": [
                "effective",
                "explicit"
              ]
            },
            "onWrite": {
              "enum": [
                "materializeIfInherited",
                "editResolvedPart",
                "error"
              ]
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType",
            "section",
            "headerFooterKind",
            "variant"
          ]
        },
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "headerFooterPart"
            },
            "refId": {
              "type": "string"
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType",
            "refId"
          ]
        },
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "footnote"
            },
            "noteId": {
              "type": "string"
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType",
            "noteId"
          ]
        },
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "endnote"
            },
            "noteId": {
              "type": "string"
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType",
            "noteId"
          ]
        },
        {
          "type": "object",
          "properties": {
            "kind": {
              "const": "story"
            },
            "storyType": {
              "const": "textbox"
            },
            "textboxId": {
              "type": "string"
            }
          },
          "additionalProperties": false,
          "required": [
            "kind",
            "storyType",
            "textboxId"
          ]
        }
      ]
    },
    "SectionAddress": {
      "type": "object",
      "properties": {
        "kind": {
          "const": "section"
        },
        "sectionId": {
          "type": "string"
        }
      },
      "additionalProperties": false,
      "required": [
        "kind",
        "sectionId"
      ]
    }
  },
  "type": "object",
  "properties": {
    "target": {
      "$ref": "#/$defs/ListItemAddress"
    },
    "direction": {
      "enum": [
        "withPrevious",
        "withNext"
      ]
    }
  },
  "additionalProperties": false,
  "required": [
    "target",
    "direction"
  ]
}
```

## Output schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$defs": {},
  "type": "object",
  "properties": {
    "canJoin": {
      "type": "boolean"
    },
    "reason": {
      "enum": [
        "NO_ADJACENT_SEQUENCE",
        "INCOMPATIBLE_DEFINITIONS",
        "ALREADY_SAME_SEQUENCE"
      ]
    },
    "adjacentListId": {
      "type": "string"
    }
  },
  "additionalProperties": false,
  "required": [
    "canJoin"
  ]
}
```

## Pre-apply throws

- `TARGET_NOT_FOUND`
- `INVALID_TARGET`
- `INVALID_INPUT`

## Non-applied receipt codes

- None