Merge pull request #10 from extradosages/multi-transact-context

feat: add context-manager dunder methods to `MultiTransact`

README.md

@@ -155,6 +155,14 @@ assert r['rows'] == [[1], [2], [3]]
 You **must** run either `tx.commit()` or `tx.abort()` at the end, otherwise
 you will have a resource leak.
 
+To automatically clean up transactions, the return value of `client.multi-transact` can be used as a context-manager which automatically aborts the transaction at the end of the context if it has not already been committed.
+```python
+with client.multi_transact(True) as tx:
+    tx.run(':create a {a})
+    tx.run('?[a] <- [[1]] :put a {a}')
+    tx.commit()
+```
+
 ### Mutation callbacks
 
 You can register functions to run whenever mutations are made against stored relations. As an example:

pycozo/client.py

@@ -330,6 +330,15 @@ class MultiTransact:
     def __init__(self, multi_tx):
         self.multi_tx = multi_tx
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self):
+        try:
+            self.abort()
+        except:
+            pass
+
     def commit(self):
         return self.multi_tx.commit()