imp:journal: balance transactions with local precisions [#2402]

hledger-lib/Hledger/Data/Balancing.hs

@@ -34,6 +34,7 @@ import Control.Monad.Reader as R (ReaderT, reader, runReaderT, ask, asks)
 import Control.Monad.ST (ST, runST)
 import Control.Monad.Trans.Class (lift)
 import Data.Array.ST (STArray, getElems, newListArray, writeArray)
+import Data.Bifunctor (second)
 import Data.Foldable (asum)
 import Data.Function ((&))
 import Data.Functor ((<&>), void)
@@ -49,7 +50,6 @@ import qualified Data.Map as M
 import Safe (headErr)
 import Text.Printf (printf)
 
-import Hledger.Utils
 import Hledger.Data.Types
 import Hledger.Data.AccountName (isAccountNamePrefixOf)
 import Hledger.Data.Amount
@@ -57,7 +57,7 @@ import Hledger.Data.Journal
 import Hledger.Data.Posting
 import Hledger.Data.Transaction
 import Hledger.Data.Errors
-import Data.Bifunctor (second)
+import Hledger.Utils
 
 
 data BalancingOpts = BalancingOpts
@@ -92,7 +92,8 @@ defbalancingopts = BalancingOpts
 --    (using the given display styles if provided)
 --
 transactionCheckBalanced :: BalancingOpts -> Transaction -> [String]
-transactionCheckBalanced BalancingOpts{commodity_styles_} t = errs
+-- transactionCheckBalanced BalancingOpts{commodity_styles_=_mstyles} t = errs
+transactionCheckBalanced _ t = errs
   where
     -- get real and balanced virtual postings, to be checked separately
     (rps, bvps) = foldr partitionPosting ([], []) $ tpostings t
@@ -109,10 +110,9 @@ transactionCheckBalanced BalancingOpts{commodity_styles_} t = errs
       | costPostingTagName `elem` map fst (ptags p) = mixedAmountStripCosts $ pamount p
       | otherwise                                   = mixedAmountCost $ pamount p
 
-    -- transaction balancedness is checked at each commodity's display precision
-    lookszero = mixedAmountLooksZero . atdisplayprecision
-      where
-        atdisplayprecision = maybe id styleAmounts $ commodity_styles_
+    lookszero = mixedAmountLooksZero .
+      -- maybe id styleAmounts _mstyles                                -- when rounded with global/journal precisions
+      styleAmounts (transactionCommodityStylesWith HardRounding t)  -- when rounded with transaction's precisions
 
     -- when there's multiple non-zeros, check they do not all have the same sign
     (rsignsok, bvsignsok) = (signsOk rps, signsOk bvps)

hledger-lib/Hledger/Data/Transaction.hs

@@ -33,6 +33,8 @@ module Hledger.Data.Transaction
 , transactionMapPostings
 , transactionMapPostingAmounts
 , transactionAmounts
+, transactionCommodityStyles
+, transactionCommodityStylesWith
 , transactionNegate
 , partitionAndCheckConversionPostings
 , transactionAddTags
@@ -483,6 +485,17 @@ transactionMapPostingAmounts f  = transactionMapPostings (postingTransformAmount
 transactionAmounts :: Transaction -> [MixedAmount]
 transactionAmounts = map pamount . tpostings
 
+-- | Get the canonical amount styles inferred from this transaction's amounts.
+transactionCommodityStyles :: Transaction -> M.Map CommoditySymbol AmountStyle
+transactionCommodityStyles =
+  either (const mempty) id .  -- ignore style problems, commodityStylesFromAmounts doesn't report them currently
+  commodityStylesFromAmounts . concatMap (amountsRaw . pamount) . tpostings
+
+-- | Like transactionCommodityStyles, but attach a particular rounding strategy to the styles,
+-- affecting how they will affect display precisions when applied.
+transactionCommodityStylesWith :: Rounding -> Transaction -> M.Map CommoditySymbol AmountStyle
+transactionCommodityStylesWith r = amountStylesSetRounding r . transactionCommodityStyles
+
 -- | Flip the sign of this transaction's posting amounts (and balance assertion amounts).
 transactionNegate :: Transaction -> Transaction
 transactionNegate = transactionMapPostings postingNegate

hledger/test/journal/precision.test

@@ -188,3 +188,16 @@ $ hledger -f - bal -O csv
 "b","1 JPY"
 "c","1000 JPY"
 "Total:","1002 JPY"
+
+# ** 13. An entry like this, generated by bean-report, did not balance in hledger <=1.43,
+# because the P amount influenced the commodity's display (and balancing) precision.
+# From 1.44 transaction balancing uses the transaction's local precisions,
+# so CNY's precision is 2 and this does balance.
+<
+P 2025-01-01 USD  7.147224669603524229074889868 CNY
+
+2025-01-01
+  a   -113.50 USD @ 7.147224669603524229074889868 CNY
+  a    811.21 CNY
+
+$ hledger -f - check