extractor

extractor

Expected Schema Extractor

This module builds the expected schema from migration operations without touching the database. It serves as the bridge between migration code (Input 2) and the expected database state.

This expected schema is used in Comparison B: Reality Check (expected ↔ actual) to detect: - Schema drift - Manual database edits - Broken legacy assumptions

The extractor replays migration operations to construct what the database should look like based on the recorded migration history.

SCHEMA_OPS = (models.CreateModel, models.DeleteModel, fields.AddField, fields.RemoveField, fields.AlterField, models.AlterModelTable, models.AddIndex, models.RemoveIndex, models.AddConstraint, models.RemoveConstraint) module-attribute

MigrationExtractor(migration_graph, applied_nodes)

Projects a schema state purely from migration operations, without touching the database.

graph = migration_graph instance-attribute

applied_nodes = applied_nodes instance-attribute

build_state()

Build the expected schema state from applied migrations.