Merge bitcoin#12486: [test] Round target fee to 8 decimals in assert_…

…fee_amount

42e1b5d [test] Round target fee to 8 decimals in assert_fee_amount (Karl-Johan Alm)

Pull request description:

  The output would produce arbitrary number of decimal points, sometimes resulting in 9 decimals:
  ```
  AssertionError: Fee of 0.00000415 BTC too low! (Should be 0.000006175 BTC)
  ```
  The above looks like the expected fee is 6175 sats when in reality it's 618.

Tree-SHA512: ddbff2926a88890d6e34a58db36f0b15a917a80064be6e40e9bcbec3f05ae6202d02adcd7873733945b043fa121d4a56dd930446ec368078fe1935cbfff898ce

test/functional/test_framework/util.py

@@ -29,7 +29,7 @@
 
 def assert_fee_amount(fee, tx_size, fee_per_kB):
     """Assert the fee was in range"""
-    target_fee = tx_size * fee_per_kB / 1000
+    target_fee = round(tx_size * fee_per_kB / 1000, 8)
     if fee < target_fee:
         raise AssertionError("Fee of %s DASH too low! (Should be %s DASH)" % (str(fee), str(target_fee)))
     # allow the wallet's estimation to be at most 2 bytes off