Balance assertions for hledger

First developer diary entry. I am inspired by Joey Hess’s terrific daily git-annex dev posts over the last year.

Today I began adding ledger’s balance assertions feature to hledger, since it’s next in the 0.21 todo list on the hledger planning board.

This lets you write =EXPECTEDBALANCE after a posting in a journal file, in which case the parser will check the running total in that account after that posting, and fail if it’s not EXPECTEDBALANCE. This will be very good for preventing errors such as instability in reconciled balances caused by “harmless” cleanups in old data…

In this 45 minute session I:

• checked repo status on vps and local machine
• looked for relevant notes/docs
• reviewed existing (dummy) balance assertion parser
• added balance assertion amount field to Posting and parser
• tried to add a parser test.. this was ignored because of #ifdef TESTS (not defined)
• researched that. It seems to be specific to the JournalReader module, where I experimented with HTF, a newer test framework which isn’t available on windows
• added -DTESTS to default build flags in makefile to get HTF tests building; found that they aren’t compiling
• found hledger-lib.cabal doesn’t set TESTS or specify the HTF dependency
• installed HTF
• found that test-framework and HTF have a conflicting Test.Framework module. Which seems a bit silly in two 5-year old test libs.

And there we have it. In the next session I hope to finish cleaning up this test mess, and remember the design I had in mind for implementing this.