Update Composer, update everything

web/core/modules/book/migrations/book_settings.yml

@@ -0,0 +1,20 @@
+id: book_settings
+label: Book configuration
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+  - Configuration
+source:
+  plugin: variable
+  variables:
+    - book_child_type
+    - book_block_mode
+    - book_allowed_types
+  source_module: book
+process:
+  child_type: book_child_type
+  'block/navigation/mode': book_block_mode
+  allowed_types: book_allowed_types
+destination:
+  plugin: config
+  config_name: book.settings

web/core/modules/book/migrations/d6_book.yml

@@ -0,0 +1,24 @@
+id: d6_book
+label: Books
+migration_tags:
+  - Drupal 6
+  - Content
+source:
+  plugin: book
+process:
+  nid: nid
+  'book/bid': bid
+  'book/weight': weight
+  'book/pid':
+    -
+      plugin: skip_on_empty
+      method: process
+      source: plid
+    -
+      plugin: migration_lookup
+      migration: d6_book
+destination:
+  plugin: book
+migration_dependencies:
+  required:
+    - d6_node

web/core/modules/book/migrations/d7_book.yml

@@ -0,0 +1,24 @@
+id: d7_book
+label: Books
+migration_tags:
+  - Drupal 7
+  - Content
+source:
+  plugin: book
+process:
+  nid: nid
+  'book/bid': bid
+  'book/weight': weight
+  'book/pid':
+    -
+      plugin: skip_on_empty
+      method: process
+      source: plid
+    -
+      plugin: migration_lookup
+      migration: d7_book
+destination:
+  plugin: book
+migration_dependencies:
+  required:
+    - d7_node