refactored

jaydiff/README.jaydiff.md

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+# jay_diff — JSON diff / patch library
+
+`utils/jay_diff.py` is a lightweight, pure-Python library for computing and
+applying structural diffs between two JSON-compatible dicts.  It is used by
+`collect.py` and `gui_client.py` to compress the push-server stream: instead
+of retransmitting full snapshots on every poll, the server sends only the
+fields that changed since the previous snapshot.
+
+---
+
+## Concepts
+
+A **diff** is itself a plain dict.  It describes what changed from an **old**
+state to a **new** state using one or more of these keys:
+
+| Key | Meaning |
+|-----|---------|
+| `update_add` | Fields whose value changed *or* that are new in `new` |
+| `update` | Fields whose value changed (must already exist in `old`) |
+| `add` | Fields that are new in `new` (did not exist in `old`) |
+| `delete` | Fields that were removed or whose sub-keys were pruned |
+
+`update_add` combines `update` and `add` into a single key (the mode used
+everywhere in this project).  The separate `update` / `add` form is
+available via `combine_upd_add=False` for completeness.
+
+An **empty dict `{}`** returned by `jay_diff_full` means the two states are
+identical.
+
+### Delete-delta encoding
+
+Values inside the `delete` sub-dict carry a specific meaning:
+
+| Value in delete delta | Effect when merged |
+|-----------------------|--------------------|
+| `None` | The **entire key** is deleted from `old` |
+| A **non-empty dict** | Recurse into the sub-dict and delete those specific sub-keys; the parent key is kept (possibly as `{}`) |
+| A **scalar** (string, int, …) | The key is deleted from `old` |
+| `{}` (empty dict) | The key is deleted from `old` |
+
+This distinction matters when the new state has an empty dict `{}` at a
+location where the old state had a populated dict.  In that case the delete
+delta carries the populated sub-keys as a non-empty dict — after merging,
+the parent key is preserved as `{}`.  If the key is entirely absent from
+the new state, `None` is stored in the delta, and the merge removes the key
+completely.
+
+---
+
+## API
+
+### Diff functions
+
+```python
+jay_diff_full(old, new, combine_upd_add=True) -> dict
+```
+The main entry point.  Computes a complete diff from `old` to `new`.
+
+- `combine_upd_add=True` (default) — produces `update_add` + `delete`
+- `combine_upd_add=False` — produces `update` + `add` + `delete`
+
+Returns `{}` when `old == new`.
+
+```python
+jay_diff_add(old, new) -> dict
+```
+Returns keys present in `new` but absent from `old` (additions only).
+
+```python
+jay_diff_del(old, new) -> dict
+```
+Returns keys present in `old` but absent from `new`, or sub-keys that were
+removed from a shared dict.  Uses `None` as sentinel for entirely-absent
+dict keys.
+
+```python
+jay_diff_upd(old, new) -> dict
+```
+Returns keys present in both `old` and `new` whose values differ (updates
+only; new keys are ignored).
+
+```python
+jay_diff_upd_add(old, new) -> dict
+```
+Like `jay_diff_upd` but also includes keys new in `new` — equivalent to
+`jay_diff_full(..., combine_upd_add=True)` minus the delete section.
+
+---
+
+### Merge functions
+
+```python
+jay_merge_full(old, diff) -> dict
+```
+The main entry point.  Applies a diff produced by `jay_diff_full` to `old`
+and returns the reconstructed new state.
+
+**Bootstrap passthrough:** if `old` is `{}` and `diff` contains none of the
+recognised diff keys, `diff` is returned as-is.  This is how the first
+message from the push server is handled: the server sends
+`jay_diff_full({}, record[0])`, which looks like a plain snapshot, and the
+client stores it directly.
+
+Applies operations in order: `update` → `update_add` → `add` → `delete`.
+
+```python
+jay_merge_update(old, new) -> dict   # apply an update/update_add delta
+jay_merge_add(old, new)    -> dict   # apply an add delta
+jay_merge_delete(old, new) -> dict   # apply a delete delta
+```
+Low-level helpers; prefer `jay_merge_full` unless you need fine-grained
+control.
+
+---
+
+## Round-trip guarantee
+
+```
+jay_merge_full(old, jay_diff_full(old, new)) == new
+```
+
+This holds for all inputs where values are JSON-compatible scalars (strings,
+numbers, booleans, `None`, lists) or nested dicts thereof.  It is verified
+by `tests/test_jay_diff_real_data.py` against 674 consecutive pairs of real
+vehicle snapshots.
+
+---
+
+## Wire format
+
+`jay_diff_full` / `jay_merge_full` are used by the push server when
+`--diff` is enabled.  The diff dict is serialised as a newline-delimited
+JSON line.
+
+- The **first** message to a new client is `jay_diff_full({}, record[0])`,
+  which always contains `update_add` with every field of the first record.
+- Subsequent messages contain only the changed fields.
+- The format is self-describing: a message with none of the diff keys is
+  treated as a full snapshot by `jay_merge_full` (bootstrap passthrough).
+
+`null` in JSON round-trips to Python `None`, so the delete sentinel survives
+serialisation transparently.
+
+---
+
+## Tests
+
+```
+tests/test_jay_diff.py           — 104 unit tests (all diff/merge functions,
+                                    corner cases: type changes, empty dicts,
+                                    deep nesting, round-trips)
+tests/test_jay_diff_real_data.py — parametrised over 675 real VW snapshots
+                                    in tests/data/ (674 consecutive pairs):
+                                    round-trip, identical diff = {}, and
+                                    empty-diff-is-noop checks
+```
+
+Run with:
+
+```bash
+pytest tests/
+```
+
+---
+
+## Bug history
+
+### `jay_merge_delete`: crash on aliased dicts (fixed)
+
+`jay_diff_rev` (used internally by the old `jay_diff_del`) stored references
+to sub-dicts of `_old` directly in the delete delta without copying them.
+When `jay_merge_full(old, jay_diff_full(old, new))` was called, some
+sub-dicts in the delete delta were the same Python objects as sub-dicts in
+`old`.  Iterating `_new.items()` while deleting from `_old` (the same
+object) raised `RuntimeError: dictionary changed size during iteration`.
+
+**Fix:** `list(_new.items())` snapshots the items before the loop.  Also,
+`jay_diff_del` was rewritten as a standalone recursive function that never
+stores aliases to its inputs.
+
+### `jay_merge_delete`: empty dict wrongly pruned (fixed)
+
+When the new state had an empty dict `{}` at a location where the old state
+had a non-empty dict, `jay_merge_delete` would delete all sub-keys and then
+prune the now-empty parent key entirely.  The result differed from `new`,
+which retained the parent key as `{}`.
+
+Root cause: the old delta format stored the full old sub-dict for both "key
+absent from new" and "key present but empty in new" — the two cases were
+indistinguishable at merge time.
+
+**Fix:** `jay_diff_del` now stores `None` for dict keys entirely absent from
+`new`, and a non-empty sub-dict for partial deletions.  `jay_merge_delete`
+no longer prunes: a `None` (or scalar) value in the delta is the explicit
+signal to remove the parent key.

jaydiff/__init__.py

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+from diff.diff import (
+    jay_diff_add, jay_diff_del, jay_diff_upd, jay_diff_upd_add,
+    jay_diff_full, jay_merge_add, jay_merge_delete, jay_merge_update, jay_merge_full,
+)

jaydiff/diff.py

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+from copy import deepcopy
+
+
+def diff_rev(_old, _new):
+	delta = {}
+	if not isinstance(_old, dict):
+		return delta
+	for k in _new.keys():
+		if k in _old:
+			if isinstance(_new[k], dict):
+				res = diff_rev(_old[k], _new[k])
+				if len(res.keys()):
+					delta[k] = res
+		else:
+			_old[k] = _new[k]
+			delta[k] = _new[k]
+
+	return delta
+
+
+def diff_add(_old, _new):
+	__old = deepcopy(_old)
+	delta = diff_rev(__old, _new)
+	return delta
+
+
+def diff_del(_old, _new):
+	delta = {}
+	for k in _old:
+		if k in _new:
+			if isinstance(_old[k], dict) and isinstance(_new[k], dict):
+				sub = diff_del(_old[k], _new[k])
+				if sub:
+					delta[k] = sub
+		else:
+			# key absent from _new: None signals "delete entire key" for dicts
+			delta[k] = None if isinstance(_old[k], dict) else _old[k]
+	return delta
+
+
+def diff_upd(_old, _new, add_if_not_exist=False):
+	delta = {}
+	for k in _new.keys():
+		if k in _old:
+			if isinstance(_new[k], dict):
+				res = diff_upd(_old[k], _new[k], add_if_not_exist)
+				if len(res.keys()):
+					delta[k] = res
+			elif _new[k] != _old[k]:
+				delta[k] = _new[k]
+		elif add_if_not_exist:
+			delta[k] = _new[k]
+
+	return delta
+
+
+def diff_upd_add(_old, _new):
+	return diff_upd(_old, _new, add_if_not_exist=True)
+
+
+def diff_full(_old, _new, combine_upd_add=True):
+	diff = {}
+	if combine_upd_add:
+		res = diff_upd_add(_old, _new)
+		if len(res.keys()):
+			diff['update_add'] = res
+		res = diff_del(_old, _new)
+		if len(res.keys()):
+			diff['delete'] = res
+	else:
+		res = diff_upd(_old, _new)
+		if len(res.keys()):
+			diff['update'] = res
+		res = diff_add(_old, _new)
+		if len(res.keys()):
+			diff['add'] = res
+		res = diff_del(_old, _new)
+		if len(res.keys()):
+			diff['delete'] = res
+
+	return diff
+
+def _legacy_assertions() -> None:
+	result = diff_add({}, {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = diff_add({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {}
+
+	result = diff_add({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'})
+	assert result == {}
+
+	result = diff_add({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'})
+	assert result == {'d':'icecream'}
+
+	result = diff_add({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {'b':'fries'}
+
+	result = diff_add({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}})
+	assert result == {'c': {'f': 'coffee'}}
+
+	result = diff_add({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}})
+	assert result == {}
+
+	result = diff_del({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {'d':'icecream'}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'})
+	assert result == {}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries'})
+	assert result == {'c':'pepsi'}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries'})
+	assert result == {'c': None}
+
+	result = diff_del({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}}
+
+	result = diff_del({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}})
+	assert result == {}
+
+	result = diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes'})
+	assert result == {'a':'hotdog', 'b':'potatoes'}
+
+	result = diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi'}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	result = diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'})
+	assert result == {'a':'hotdog'}
+
+	result = diff_upd({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'})
+	assert result == {'c':'coke'}
+
+	result = diff_upd({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {'c':'coke'}
+
+	result = diff_upd({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}})
+	assert result == {}
+
+	result = diff_upd({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	# Update/add
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'})
+	assert result == {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}, 'b':'potatoes'})
+	assert result == {'b':'potatoes', 'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'})
+	assert result == {'a':'hotdog'}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	#####################
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes'})
+	assert result == {'a':'hotdog', 'b':'potatoes'}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi'}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'})
+	assert result == {'a':'hotdog'}
+
+	result = diff_upd_add({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'})
+	assert result == {'c': 'coke', 'd': 'icecream'}
+
+	result = diff_upd_add({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'})
+	assert result == {'b': 'fries', 'c': 'coke'}
+
+	result = diff_upd_add({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}})
+	assert result == {'c': {'f': 'coffee'}}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	result = diff_upd_add({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee', 'h': 'cake'}})
+	assert result == {'c': {'e': 'pepsi', 'h': 'cake'}}
+
+	# diff_full
+	combine_upd_add = False
+
+	result = diff_full({}, {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'update': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, combine_upd_add)
+	assert result == {'delete': {'d': 'icecream'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'}, combine_upd_add)
+	assert result == {'add': {'d': 'icecream'}, 'delete': {'b': 'fries'}, 'update': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'add': {'b': 'fries'}, 'delete': {'d': 'icecream'}, 'update': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}}, combine_upd_add)
+	assert result == {'add': {'c': {'f': 'coffee'}}, 'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}}
+
+	result = diff_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'add': {'b': 'fries'}, 'delete': {'d': 'icecream'}, 'update': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, combine_upd_add)
+	assert result == {'update': {'c': 'pepsi'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': 'pepsi'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'update': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, combine_upd_add)
+	assert result == {'delete': {'c': {'e': 'coke'}}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}}, combine_upd_add)
+	assert result == {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update': {'a': 'hotdog', 'b': 'potatoes'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi'}}, combine_upd_add)
+	assert result == {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, 'update': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update': {'a': 'hotdog'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'}, combine_upd_add)
+	assert result == {'add': {'d': 'icecream'}, 'delete': {'c': None}, 'update': {'a': 'hotdog', 'b': 'potatoes'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}, 'b':'potatoes'}, combine_upd_add)
+	assert result == {'add': {'c': {'g': 'tea', 'h': 'cake'}}, 'delete': {'a': 'hamburger', 'c': {'f': 'coffee'}}, 'update': {'b': 'potatoes', 'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update': {'a': 'hotdog'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee', 'h': 'cake'}}, combine_upd_add)
+	assert result == {'add': {'c': {'h': 'cake'}}, 'update': {'c': {'e': 'pepsi'}}}
+
+	# ToDo: diff_full
+	combine_upd_add = True
+
+	result = diff_full({}, {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update_add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'update_add': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, combine_upd_add)
+	assert result == {'delete': {'d': 'icecream'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'}, combine_upd_add)
+	assert result == {'delete': {'b': 'fries'}, 'update_add': {'c': 'coke', 'd': 'icecream'}}
+
+	result = diff_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'delete': {'d': 'icecream'}, 'update_add': {'b': 'fries', 'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'c': {'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update_add': {'c': {'f': 'coffee'}}, 'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}}
+
+	result = diff_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'delete': {'d': 'icecream'}, 'update_add': {'b': 'fries', 'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, combine_upd_add)
+	assert result == {'update_add': {'c': 'pepsi'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': 'pepsi'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, combine_upd_add)
+	assert result == {'update_add': {'c': 'coke'}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, combine_upd_add)
+	assert result == {'delete': {'c': {'e': 'coke'}}}
+
+	result = diff_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}}, combine_upd_add)
+	assert result == {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update_add': {'a': 'hotdog', 'b': 'potatoes'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi'}}, combine_upd_add)
+	assert result == {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, 'update_add': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update_add': {'a': 'hotdog'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update_add': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update_add': {'a': 'hotdog', 'b': 'potatoes', 'd': 'icecream'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}, 'b':'potatoes'}, combine_upd_add)
+	assert result == {'delete': {'a': 'hamburger', 'c': {'f': 'coffee'}}, 'update_add': {'b': 'potatoes', 'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hotdog', 'b':'fries'}, combine_upd_add)
+	assert result == {'delete': {'c': None}, 'update_add': {'a': 'hotdog'}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}, combine_upd_add)
+	assert result == {'update_add': {'c': {'e': 'pepsi'}}}
+
+	result = diff_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee', 'h': 'cake'}}, combine_upd_add)
+	assert result == {'update_add': {'c': {'e': 'pepsi', 'h': 'cake'}}}
+
+if __name__ == '__main__':
+	_legacy_assertions()

jaydiff/merge.py

@@ -0,0 +1,262 @@
+from copy import deepcopy
+
+
+def merge_update(_old, _new):
+	for k, v in _new.items():
+		if isinstance(v, dict):
+			r = merge_update(_old.get(k, {}), v)
+			_old[k] = r
+		else:
+			if isinstance(_old, dict):
+				_old[k] = _new[k]
+			else:
+				_old = _new
+	return _old
+
+
+def merge_add(_old, _new):
+	for k, v in _new.items():
+		if isinstance(v, dict):
+			r = merge_add(_old.get(k, {}), v)
+			if k in _old:
+				_old[k].update(r)
+			else:
+				_old[k] = r
+		else:
+			_old[k] = _new[k]
+	return _old
+
+
+def merge_delete(_old, _new):
+	for k, v in list(_new.items()):
+		if isinstance(v, dict) and v:
+			if k in _old and isinstance(_old[k], dict):
+				merge_delete(_old[k], v)
+		else:
+			if k in _old:
+				del _old[k]
+	return _old
+
+
+def merge_full(_old, _diff):
+	_is_diff = False
+	res = _old
+	if "update" in _diff:
+		res = merge_update(res, _diff['update'])
+		_is_diff = True
+	if "update_add" in _diff:
+		res = merge_update(res, _diff['update_add'])
+		_is_diff = True
+	if "add" in _diff:
+		res = merge_add(res, _diff['add'])
+		_is_diff = True
+	if "delete" in _diff:
+		res = merge_delete(res, _diff['delete'])
+		_is_diff = True
+
+	if not _is_diff and not _old:
+		res = _diff
+
+	return res
+
+def _legacy_assertions() -> None:
+	# Merge
+	result = merge_add({}, {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = merge_add({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'d': 'icecream'})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}, 'd':'icecream'}
+
+	result = merge_add({'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, {'d': 'icecream'})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}, 'd':'icecream'}
+
+	result = merge_add({'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}, 'd': 'icecream'}, {'d': 'icecream'})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}, 'd':'icecream'}
+
+	result = merge_delete({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}, 'd': 'icecream'}, {'d': 'icecream'})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = merge_delete({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'f': 'coffee'}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'coke'}}
+
+	result = merge_delete({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'c': {'e': 'coke'}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'f': 'coffee'}}
+
+	# merge_full
+	# the no-jaydiff case
+	result = merge_full({}, {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	# combine_upd_add = False
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'update': {'c': 'pepsi'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi', 'd': 'icecream'}, {'delete': {'d': 'icecream'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'add': {'d': 'icecream'}, 'delete': {'b': 'fries'}, 'update': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'add': {'b': 'fries'}, 'delete': {'d': 'icecream'}, 'update': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'add': {'c': {'f': 'coffee'}}, 'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}})
+	assert result == {'c': {'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'add': {'b': 'fries'}, 'delete': {'d': 'icecream'}, 'update': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'update': {'c': 'pepsi'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'delete': {'c': 'pepsi'}})
+	assert result == {'a': 'hamburger', 'b': 'fries'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'update': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}})
+	assert result == {'a': 'hamburger', 'b': 'fries'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': {'e': 'coke'}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}})
+	assert result == {'c': {'e': 'coke'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update': {'a': 'hotdog', 'b': 'potatoes'}})
+	assert result == {'a':'hotdog', 'b':'potatoes'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, 'update': {'c': {'e': 'pepsi'}}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update': {'a': 'hotdog'}})
+	assert result == {'a':'hotdog', 'b':'fries'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'update': {'c': {'e': 'pepsi'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'add': {'d': 'icecream'}, 'delete': {'c': None}, 'update': {'a': 'hotdog', 'b': 'potatoes'}})
+	assert result == {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'add': {'c': {'g': 'tea', 'h': 'cake'}}, 'delete': {'a': 'hamburger', 'c': {'f': 'coffee'}}, 'update': {'b': 'potatoes', 'c': {'e': 'pepsi'}}})
+	assert result == {'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}, 'b':'potatoes'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update': {'a': 'hotdog'}})
+	assert result == {'a':'hotdog', 'b':'fries'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'update': {'c': {'e': 'pepsi'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'add': {'c': {'h': 'cake'}}, 'update': {'c': {'e': 'pepsi'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee', 'h': 'cake'}}
+
+	# ToDo: merge_full
+	# combine_upd_add = True
+
+	result = merge_full({}, {'update_add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'update_add': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi', 'd': 'icecream'}, {'delete': {'d': 'icecream'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'delete': {'b': 'fries'}, 'update_add': {'c': 'coke', 'd': 'icecream'}})
+	assert result == {'a': 'hamburger', 'd': 'icecream', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'delete': {'d': 'icecream'}, 'update_add': {'b': 'fries', 'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}, {'update_add': {'c': {'f': 'coffee'}}, 'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke'}}})
+	assert result == {'c': {'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'c': 'pepsi', 'd': 'icecream'}, {'delete': {'d': 'icecream'}, 'update_add': {'b': 'fries', 'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'coke'}, {'update_add': {'c': 'pepsi'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'delete': {'c': 'pepsi'}})
+	assert result == {'a': 'hamburger', 'b': 'fries'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': 'pepsi'}, {'update_add': {'c': 'coke'}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': 'coke'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}})
+	assert result == {'a': 'hamburger', 'b': 'fries'}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': {'e': 'coke'}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}})
+	assert result == {'c': {'e': 'coke'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update_add': {'a': 'hotdog', 'b': 'potatoes'}})
+	assert result == {'a':'hotdog', 'b':'potatoes'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'a': 'hamburger', 'b': 'fries', 'c': {'f': 'coffee'}}, 'update_add': {'c': {'e': 'pepsi'}}})
+	assert result == {'c': {'e': 'pepsi'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update_add': {'a': 'hotdog'}})
+	assert result == {'a':'hotdog', 'b':'fries'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'update_add': {'c': {'e': 'pepsi'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update_add': {'a': 'hotdog', 'b': 'potatoes', 'd': 'icecream'}})
+	assert result == {'a':'hotdog', 'b':'potatoes', 'd': 'icecream'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'a': 'hamburger', 'c': {'f': 'coffee'}}, 'update_add': {'b': 'potatoes', 'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}}})
+	assert result == {'b':'potatoes', 'c': {'e': 'pepsi', 'g': 'tea', 'h': 'cake'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'delete': {'c': None}, 'update_add': {'a': 'hotdog'}})
+	assert result == {'a':'hotdog', 'b':'fries'}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'update_add': {'c': {'e': 'pepsi'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee'}}
+
+	result = merge_full({'a':'hamburger', 'b':'fries', 'c': {'e': 'coke', 'f': 'coffee'}}, {'update_add': {'c': {'e': 'pepsi', 'h': 'cake'}}})
+	assert result == {'a':'hamburger', 'b':'fries', 'c': {'e': 'pepsi', 'f': 'coffee', 'h': 'cake'}}
+
+	result = merge_full({}, {'add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': 'coffee'}}
+
+	result = merge_full({}, {'add': {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': {'coffee': {'h': 'black'}}}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': {'coffee': {'h': 'black'}}}}
+
+	result = merge_full({'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': {'coffee': {'h': 'black'}}}}, {'add': {'c': {'f': {'coffee': {'j': 'sugar'}}}}})
+	assert result == {'a': 'hamburger', 'b': 'fries', 'c': {'e': 'coke', 'f': {'coffee': {'h': 'black', 'j': 'sugar'}}}}
+
+	old = {'charging': {
+		'batteryStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:34Z', 'cruisingRangeElectric_km': 192}},
+		'chargingStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:34Z'}},
+		'chargingSettings': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:30Z'}},
+		'plugStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:29Z'}}}}
+	update = {'charging': {
+		'batteryStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:35:46Z', 'cruisingRangeElectric_km': 191}},
+		'chargingStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:35:46Z'}}}}
+	add = {'charging': {
+		'batteryStatus': {'value': {'currentSOC_pct': 55}}},
+		'fuelStatus': {'rangeStatus': {'value': {'primaryEngine': {'currentSOC_pct': 55}}}},
+		'measurements': {'fuelLevelStatus': {'value': {'currentSOC_pct': 55}}}}
+
+	delete = {'charging': {
+		'chargingSettings': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:30Z'}},
+		'plugStatus': {'value': {'carCapturedTimestamp': '2024-10-19T05:34:29Z'}}}}
+
+	result = merge_full(old, {'update':update, 'add':add, 'delete':delete})
+	assert result == old
+
+if __name__ == '__main__':
+	_legacy_assertions()