micropython: add micropython component

components/language/micropython/tests/extmod/btree_gc.py

@@ -0,0 +1,26 @@
+# Test btree interaction with the garbage collector.
+
+try:
+    import btree, uio, gc
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+N = 80
+
+# Create a BytesIO but don't keep a reference to it.
+db = btree.open(uio.BytesIO(), pagesize=512)
+
+# Overwrite lots of the Python stack to make sure no reference to the BytesIO remains.
+x = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+# Write lots of key/value pairs, which fill up the DB and also allocate temporary heap
+# memory due to the string addition, and do a GC collect to verify that the BytesIO
+# is not collected.
+for i in range(N):
+    db[b"thekey" + str(i)] = b"thelongvalue" + str(i)
+    print(db[b"thekey" + str(i)])
+    gc.collect()
+
+# Reclaim memory allocated by the db object.
+db.close()