close: use exact, minimal amounts; ensure assertions pass (#941)

hledger/Hledger/Cli/Commands/Close.hs

@@ -34,8 +34,11 @@ This command may also be useful for closing out expense/income accounts
 for a period (ie "closing the books" in accounting).
 
 Both transactions include balance assertions for the closed/reopened accounts.
+
 You probably shouldn't use status or realness queries (eg -C or -R) with this 
 command, or the balance assertions will require that query to pass.
+Likewise, if you generate them with --auto, the assertions will depend on
+any auto postings and --auto will be required to make them pass.
 
 By default, the closing transaction is dated yesterday, with balances 
 calculated as of end of yesterday, and the opening transaction is dated today.
@@ -83,17 +86,22 @@ close CliOpts{rawopts_=rawopts, reportopts_=ropts} j = do
       closingdate = addDays (-1) openingdate
       (acctbals,_) = balanceReportFromMultiBalanceReport ropts_ q j
       balancingamt = negate $ sum $ map (\(_,_,_,b) -> normaliseMixedAmountSquashPricesForDisplay b) acctbals
+
+      -- since balance assertion amounts are required to be exact, the
+      -- amounts in opening/closing transactions should be too (#941)
+      -- setprec = setFullPrecision
+      setprec = setMinimalPrecision
       ps = [posting{paccount=a
-                   ,pamount=mixed [b]
-                   ,pbalanceassertion=Just assertion{ baamount=b }
+                   ,pamount=mixed [setprec b]
+                   ,pbalanceassertion=Just assertion{ baamount=setprec b }
                    }
            |(a,_,_,mb) <- acctbals
            ,b <- amounts $ normaliseMixedAmountSquashPricesForDisplay mb
            ]
            ++ [posting{paccount="equity:opening balances", pamount=balancingamt}]
       nps = [posting{paccount=a
-                    ,pamount=mixed [negate b]
-                    ,pbalanceassertion=Just assertion{ baamount=b{aquantity=0} }
+                    ,pamount=mixed [setprec $ negate b]
+                    ,pbalanceassertion=Just assertion{ baamount= setprec b{aquantity=0} }
                     }
             |(a,_,_,mb) <- acctbals
             ,b <- amounts $ normaliseMixedAmountSquashPricesForDisplay mb

tests/misc/close.test

@@ -1,5 +1,5 @@
 
-# Simple case
+# 1. Simple case
 hledger close -f- -p 2016 assets liabilities
 <<<
 2016/1/1 open
@@ -33,7 +33,7 @@ hledger close -f- -p 2016 assets liabilities
 
 >>>=0
 
-# Test aggregation of postings with prices
+# 2. Test aggregation of postings with prices
 hledger close -f- -p 2016 assets liabilities
 <<<
 Y2016
@@ -58,18 +58,18 @@ Y2016
 	liabilities:employer
 >>>
 2016/12/31 closing balances
-    assets:bank                -5,733.00 EUR = 0.00 EUR
-    liabilities:employer           -1.00 EUR = 0.00 EUR
+    assets:bank                  -5,733 EUR = 0 EUR
+    liabilities:employer             -1 EUR = 0 EUR
     equity:closing balances
 
 2017/01/01 opening balances
-    assets:bank                 5,733.00 EUR = 5,733.00 EUR
-    liabilities:employer            1.00 EUR = 1.00 EUR
+    assets:bank                    5,733 EUR = 5,733 EUR
+    liabilities:employer               1 EUR = 1 EUR
     equity:opening balances
 
 >>>=0
 
-# A begin date should be ignored
+# 3. A begin date should be ignored
 hledger close -f- -b2017/6/1 -e2018
 <<<
 2017/1/1
@@ -85,7 +85,7 @@ hledger close -f- -b2017/6/1 -e2018
 
 >>>=0
 
-# Print just the opening transaction
+# 4. Print just the opening transaction
 hledger close -f- -p 2016 assets liabilities --opening
 <<<
 2016/1/1 open
@@ -113,7 +113,7 @@ hledger close -f- -p 2016 assets liabilities --opening
 
 >>>=0
 
-# Print just the closing transaction
+# 5. Print just the closing transaction
 hledger close -f- -p 2016 assets liabilities --closing
 <<<
 2016/1/1 open
@@ -141,7 +141,7 @@ hledger close -f- -p 2016 assets liabilities --closing
 
 >>>=0
 
-# Supplying --opening --closing is the same as just "close"
+# 6. Supplying --opening --closing is the same as just "close"
 hledger close -f- -p 2016 assets liabilities --opening --closing
 <<<
 2016/1/1 open