balance: ledger compatibility fix: don't elide parent accounts with multiple displayed subaccounts

hledger-lib/Hledger/Reports.hs

@@ -539,6 +539,7 @@ isInteresting :: ReportOpts -> Ledger -> AccountName -> Bool
 isInteresting opts l a | flat_ opts = isInterestingFlat opts l a
                        | otherwise = isInterestingIndented opts l a
 
+-- | Determine whether an account should get its own line in the --flat balance report.
 isInterestingFlat :: ReportOpts -> Ledger -> AccountName -> Bool
 isInterestingFlat opts l a = notempty || emptyflag
     where
@@ -546,16 +547,19 @@ isInterestingFlat opts l a = notempty || emptyflag
       notempty = not $ isZeroMixedAmount $ exclusiveBalance acct
       emptyflag = empty_ opts
 
+-- | Determine whether an account should get its own line in the indented
+-- balance report.  Cf Balance module doc.
 isInterestingIndented :: ReportOpts -> Ledger -> AccountName -> Bool
 isInterestingIndented opts l a
-    | numinterestingsubs==1 && not atmaxdepth = notlikesub
-    | otherwise = notzero || emptyflag
+    | numinterestingsubs == 1 && samebalanceassub && not atmaxdepth = False
+    | numinterestingsubs < 2 && zerobalance && not emptyflag = False
+    | otherwise = True
     where
       atmaxdepth = isJust d && Just (accountNameLevel a) == d where d = depth_ opts
       emptyflag = empty_ opts
       acct = ledgerAccount l a
-      notzero = not $ isZeroMixedAmount inclbalance where inclbalance = abalance acct
-      notlikesub = not $ isZeroMixedAmount exclbalance where exclbalance = sumPostings $ apostings acct
+      zerobalance = isZeroMixedAmount inclbalance where inclbalance = abalance acct
+      samebalanceassub = isZeroMixedAmount exclbalance where exclbalance = sumPostings $ apostings acct
       numinterestingsubs = length $ filter isInterestingTree subtrees
           where
             isInterestingTree = treeany (isInteresting opts l . aname)

hledger/Hledger/Cli.hs

@@ -249,20 +249,6 @@ tests_Hledger_Cli = TestList
         ,"                   0"
         ]
 
-   ,"balance report elides zero-balance root account(s)" ~: do
-      j <- readJournal'
-             (unlines
-              ["2008/1/1 one"
-              ,"  test:a  1"
-              ,"  test:b"
-              ])
-      accountsReportAsText defreportopts (accountsReport defreportopts nullfilterspec j) `is`
-        ["                   1  test:a"
-        ,"                  -1  test:b"
-        ,"--------------------"
-        ,"                   0"
-        ]
-
    ]
 
   ,"journalCanonicaliseAmounts" ~:

hledger/Hledger/Cli/Balance.hs

@@ -82,15 +82,14 @@ Also, the balance report shows the total of all displayed accounts, when
 that is non-zero. Here, it is displayed because the accounts shown add up
 to $-1.
 
-Here is a more precise definition of \"interesting\" accounts in ledger's
-balance report:
-
-- an account which has just one interesting subaccount branch, and which
-  is not at the report's maximum depth, is interesting if the balance is
-  different from the subaccount's, and otherwise boring.
-
-- any other account is interesting if it has a non-zero balance, or the -E
-  flag is used.
+Also, non-interesting accounts may be elided.  Here's an imperfect
+description of the ledger balance command's eliding behaviour:
+\"Interesting\" accounts are displayed on their own line. An account less
+deep than the report's max depth, with just one interesting subaccount,
+and the same balance as the subaccount, is non-interesting, and prefixed
+to the subaccount's line, unless (hledger's) --no-elide is in effect.
+An account with a zero inclusive balance and less than two interesting
+subaccounts is not displayed at all, unless --empty is in effect.
 
 -}
 

tests/eliding-balance.test

@@ -1,3 +1,4 @@
+#!/usr/bin/env shelltest
 # 1. One commodity. Zero accounts should be elided but the final total should not.
 bin/hledger -f - balance
 <<<
@@ -12,3 +13,36 @@ bin/hledger -f - balance
 --------------------
                    0
 >>>=0
+
+# 2. An uninteresting parent account (with same balance as its single subaccount) is elided by default, like ledger
+bin/hledger -f - balance --no-total
+<<<
+1/1
+  (a:b)   1
+>>>
+                   1  a:b
+>>>=0
+
+# 3. But not with --no-elide
+bin/hledger -f - balance --no-total --no-elide
+<<<
+1/1
+  (a:b)   1
+>>>
+                   1  a
+                   1    b
+>>>=0
+
+# 4. Nor when it has more than one subaccount
+bin/hledger -f - balance --no-total
+<<<
+1/1
+  (a:b)    1
+  (a:c)   -1
+>>>
+                   0  a
+                   1    b
+                  -1    c
+>>>2
+>>>=0
+