enforce balancing for bracketed virtual postings

Ledger/LedgerTransaction.hs

@@ -82,7 +82,8 @@ showLedgerTransaction' elide t =
 
 isLedgerTransactionBalanced :: LedgerTransaction -> Bool
 isLedgerTransactionBalanced (LedgerTransaction {ltpostings=ps}) = 
-    isReallyZeroMixedAmount $ costOfMixedAmount $ sum $ map pamount $ filter isReal ps
+    all (isReallyZeroMixedAmount . costOfMixedAmount . sum . map pamount)
+            [filter isReal ps, filter isBalancedVirtual ps]
 
 -- | Ensure that this entry is balanced, possibly auto-filling a missing
 -- amount first. We can auto-fill if there is just one non-virtual

Ledger/Posting.hs

@@ -31,5 +31,11 @@ showPosting (Posting s a amt _ ttype) =
 isReal :: Posting -> Bool
 isReal p = ptype p == RegularPosting
 
+isVirtual :: Posting -> Bool
+isVirtual p = ptype p == VirtualPosting
+
+isBalancedVirtual :: Posting -> Bool
+isBalancedVirtual p = ptype p == BalancedVirtualPosting
+
 hasAmount :: Posting -> Bool
 hasAmount = (/= missingamt) . pamount

Tests.hs

@@ -524,6 +524,28 @@ tests = [
         (LedgerTransaction (parsedate "2009/01/01") False "" "a" ""
          [Posting False "b" (Mixed [dollars 0]) "" RegularPosting
          ] ""))
+     assertBool "virtual postings don't need to balance"
+        (isLedgerTransactionBalanced
+        (LedgerTransaction (parsedate "2009/01/01") False "" "a" ""
+         [Posting False "b" (Mixed [dollars 1.00]) "" RegularPosting
+         ,Posting False "c" (Mixed [dollars (-1.00)]) "" RegularPosting
+         ,Posting False "d" (Mixed [dollars 100]) "" VirtualPosting
+         ] ""))
+     assertBool "balanced virtual postings need to balance among themselves"
+        (not $ isLedgerTransactionBalanced
+        (LedgerTransaction (parsedate "2009/01/01") False "" "a" ""
+         [Posting False "b" (Mixed [dollars 1.00]) "" RegularPosting
+         ,Posting False "c" (Mixed [dollars (-1.00)]) "" RegularPosting
+         ,Posting False "d" (Mixed [dollars 100]) "" BalancedVirtualPosting
+         ] ""))
+     assertBool "balanced virtual postings need to balance among themselves (2)"
+        (isLedgerTransactionBalanced
+        (LedgerTransaction (parsedate "2009/01/01") False "" "a" ""
+         [Posting False "b" (Mixed [dollars 1.00]) "" RegularPosting
+         ,Posting False "c" (Mixed [dollars (-1.00)]) "" RegularPosting
+         ,Posting False "d" (Mixed [dollars 100]) "" BalancedVirtualPosting
+         ,Posting False "e" (Mixed [dollars (-100)]) "" BalancedVirtualPosting
+         ] ""))
 
   ,"isSubAccountNameOf" ~: do
     "assets" `isSubAccountNameOf` "assets" `is` False