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Make test block connect style configurable for deterministic runs
Public commit record
88/100 · Strong
What the developer wrote
Authored by Joost Jager
Make test block connect style configurable for deterministic runs
Tests previously selected a random block connect style to improve coverage.
However, this randomness made test output non-deterministic and significantly
cluttered diffs when comparing logs before and after changes.
To address this, an LDK_TEST_CONNECT_STYLE environment variable is added to
override the random selection and enable deterministic test runs.
Note that broader coverage may be better achieved via targeted tests per
connect style or a test matrix cycling through all styles, but this change
focuses on improving reproducibility and debuggability.
✓ Specific, descriptive subject✓ Names a concrete action or component✓ Provides detailed explanatory context✓ Mentions testing or verification✓ Names security-relevant behavior explicitly
What changed, and why it matters
This change only affects internal test code. It adds an environment variable so developers can choose a fixed block-connect style during testing instead of having one picked at random. There is no production code change and no security impact.
Recommended action
No security action needed. This is a benign test-quality improvement.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The commit modifies lightning/src/ln/functional_test_utils.rs so that create_network() reads LDK_TEST_CONNECT_STYLE to select a deterministic ConnectStyle for tests, falling back to the existing random selection when the variable is absent. It also documents the variable in CONTRIBUTING.md. The change is purely test-infrastructure tooling.
Changed components
lightning/src/ln/functional_test_utils.rsCONTRIBUTING.mdInspect captured patch +37 / −1
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1bc431a..e7825ac 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -176,6 +176,20 @@ Fuzzing is heavily encouraged: you will find all related material under `fuzz/`
Mutation testing is work-in-progress; any contribution there would be warmly
welcomed.
+### Environment Variables
+
+* `LDK_TEST_CONNECT_STYLE` - Override the random block connect style used in tests for deterministic runs. Valid values:
+ * `BEST_BLOCK_FIRST`
+ * `BEST_BLOCK_FIRST_SKIPPING_BLOCKS`
+ * `BEST_BLOCK_FIRST_REORGS_ONLY_TIP`
+ * `TRANSACTIONS_FIRST`
+ * `TRANSACTIONS_FIRST_SKIPPING_BLOCKS`
+ * `TRANSACTIONS_DUPLICATIVELY_FIRST_SKIPPING_BLOCKS`
+ * `HIGHLY_REDUNDANT_TRANSACTIONS_FIRST_SKIPPING_BLOCKS`
+ * `TRANSACTIONS_FIRST_REORGS_ONLY_TIP`
+ * `FULL_BLOCK_VIA_LISTEN`
+ * `FULL_BLOCK_DISCONNECTIONS_SKIPPING_VIA_LISTEN`
+
C/C++ Bindings
--------------
diff --git a/lightning/src/ln/functional_test_utils.rs b/lightning/src/ln/functional_test_utils.rs
index e072deb..e9cb13d 100644
--- a/lightning/src/ln/functional_test_utils.rs
+++ b/lightning/src/ln/functional_test_utils.rs
@@ -4563,7 +4563,29 @@ pub fn create_network<'a, 'b: 'a, 'c: 'b>(
let mut nodes = Vec::new();
let chan_count = Rc::new(RefCell::new(0));
let payment_count = Rc::new(RefCell::new(0));
- let connect_style = Rc::new(RefCell::new(ConnectStyle::random_style()));
+
+ let connect_style = Rc::new(RefCell::new(match std::env::var("LDK_TEST_CONNECT_STYLE") {
+ Ok(val) => match val.as_str() {
+ "BEST_BLOCK_FIRST" => ConnectStyle::BestBlockFirst,
+ "BEST_BLOCK_FIRST_SKIPPING_BLOCKS" => ConnectStyle::BestBlockFirstSkippingBlocks,
+ "BEST_BLOCK_FIRST_REORGS_ONLY_TIP" => ConnectStyle::BestBlockFirstReorgsOnlyTip,
+ "TRANSACTIONS_FIRST" => ConnectStyle::TransactionsFirst,
+ "TRANSACTIONS_FIRST_SKIPPING_BLOCKS" => ConnectStyle::TransactionsFirstSkippingBlocks,
+ "TRANSACTIONS_DUPLICATIVELY_FIRST_SKIPPING_BLOCKS" => {
+ ConnectStyle::TransactionsDuplicativelyFirstSkippingBlocks
+ },
+ "HIGHLY_REDUNDANT_TRANSACTIONS_FIRST_SKIPPING_BLOCKS" => {
+ ConnectStyle::HighlyRedundantTransactionsFirstSkippingBlocks
+ },
+ "TRANSACTIONS_FIRST_REORGS_ONLY_TIP" => ConnectStyle::TransactionsFirstReorgsOnlyTip,
+ "FULL_BLOCK_VIA_LISTEN" => ConnectStyle::FullBlockViaListen,
+ "FULL_BLOCK_DISCONNECTIONS_SKIPPING_VIA_LISTEN" => {
+ ConnectStyle::FullBlockDisconnectionsSkippingViaListen
+ },
+ _ => panic!("Unknown ConnectStyle '{}'", val),
+ },
+ Err(_) => ConnectStyle::random_style(),
+ }));
for i in 0..node_count {
let dedicated_entropy = DedicatedEntropy(RandomBytes::new([i as u8; 32]));
Risk score
Our methodology →Why this scored 15/100
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