feat: ensure new miner doesn't propose a block yet

testnet/stacks-node/src/tests/signer/v0.rs

@@ -683,6 +683,11 @@ fn miner_wait_for_proposal() {
     })
     .expect("Timed out waiting for block proposal");
 
+    let proposals_before = signer_test
+        .running_nodes
+        .nakamoto_blocks_proposed
+        .load(Ordering::SeqCst);
+
     let mut block_proposal: Option<BlockProposal> = None;
 
     wait_for(30, || {
@@ -737,6 +742,16 @@ fn miner_wait_for_proposal() {
 
     TEST_IGNORE_ALL_BLOCK_PROPOSALS.lock().unwrap().take();
 
+    // Ensure that the new miner hasn't proposed any blocks yet
+    wait_for(10, || {
+        Ok(signer_test
+            .running_nodes
+            .nakamoto_blocks_proposed
+            .load(Ordering::SeqCst)
+            > proposals_before)
+    })
+    .expect_err("New miner proposed a block before we expected");
+
     // Now, generate a block response for each signer
     signer_test.spawned_signers.iter().for_each(|signer| {
         let sk = signer.config.stacks_private_key;