From 130e593280e9f0cd71bbc075250f148dae41fdb7 Mon Sep 17 00:00:00 2001
From: Jiri Suchan <jiri.suchan@reef.pl>
Date: Wed, 22 Nov 2023 15:17:43 +0700
Subject: [PATCH] fix: provide error message for mismatching upload size
 options

---
 b2sdk/transfer/emerge/planner/planner.py | 7 ++++++-
 changelog.d/b2cli934.changed.md          | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/b2cli934.changed.md

diff --git a/b2sdk/transfer/emerge/planner/planner.py b/b2sdk/transfer/emerge/planner/planner.py
index 243b07878..72fffaeb1 100644
--- a/b2sdk/transfer/emerge/planner/planner.py
+++ b/b2sdk/transfer/emerge/planner/planner.py
@@ -94,7 +94,12 @@ def __init__(
         self.min_part_size = min_part_size or DEFAULT_MIN_PART_SIZE
         self.recommended_upload_part_size = recommended_upload_part_size or DEFAULT_RECOMMENDED_UPLOAD_PART_SIZE
         self.max_part_size = max_part_size or DEFAULT_MAX_PART_SIZE
-        assert self.min_part_size <= self.recommended_upload_part_size <= self.max_part_size
+        if self.min_part_size > self.recommended_upload_part_size:
+            raise ValueError("min_part_size value (%s) exceeding recommended_upload_part_size value (%s)" % (
+                self.min_part_size, self.recommended_upload_part_size))
+        if self.recommended_upload_part_size > self.max_part_size:
+            raise ValueError("recommended_upload_part_size value (%s) exceeding max_part_size value (%s)" % (
+                self.recommended_upload_part_size, self.max_part_size))
 
     @classmethod
     def from_account_info(
diff --git a/changelog.d/b2cli934.changed.md b/changelog.d/b2cli934.changed.md
new file mode 100644
index 000000000..141e42bf0
--- /dev/null
+++ b/changelog.d/b2cli934.changed.md
@@ -0,0 +1 @@
+Replace blank `assert` with exception when size values for parts upload are misaligned.