History Entry

Historized is a mixin that adds typed, auditable change-tracking to an entity. Entities that include it gain a history field holding an immutable set of HistoryEntry records that accumulate across scope merges — no entry is ever discarded.

UserStory and Task carry Historized; UserStory overrides the field type to frozenset[UserStoryHistoryEntry] so that AC-level changes are recorded at the story level.

ChangeKind

`ChangeKind`

Bases: str, Enum

Classifies the type of change recorded in a HistoryEntry.

Attributes:

Name	Type	Description
`CREATED`		The entity was created.
`UPDATED`		One or more of the entity's fields were modified.
`DEACTIVATED`		The entity was deactivated or retired.
`SUPERSEDED`		The entity was replaced by another entity.

HistoryEntry

`HistoryEntry`

Bases: BaseModel

A timestamped record of a change made to a Historized entity.

Attributes:

Name	Type	Description
`timestamp`	`datetime`	When the change was recorded (must be timezone-aware).
`description`	`str`	Free-form prose describing what changed.
`kind`	`ChangeKind`	Categorical type of the change.
`author`	`str \| None`	Who made the change. Free-text string; defaults to None.

UserStoryHistoryEntry

`UserStoryHistoryEntry`

Bases: HistoryEntry

A HistoryEntry specialised for UserStory changes.

Extends the base entry with sets of AC ids that were added or deactivated as part of the recorded change event.

Attributes:

Name	Type	Description
`added_acs`	`frozenset[int]`	Integer ids of AcceptanceCriteria newly attached in this change.
`deactivated_acs`	`frozenset[int]`	Integer ids of AcceptanceCriteria deactivated in this change.

Historized

`Historized`

Bases: BaseModel

Mixin that adds a typed change history to an entity.

Entities inheriting this mixin carry a history field holding an immutable set of :class:~fushinryu_model.history_entry.HistoryEntry records. Subclasses may narrow the field type (e.g. to frozenset[UserStoryHistoryEntry]).

Merge semantics: history accumulates — both sides are unioned. Two entries are equal only when every field matches; identical entries appear once.

Attributes:

Name	Type	Description
`history`	`frozenset[HistoryEntry]`	Ordered set of change records. Defaults to an empty frozenset.