inacuracy result which read from contract in truffle test

[sekisamu]

below is console logging:

market-contracts git:(master) ✗ truffle test

Using network 'development'.



  Contract: ClockAuction deployment
contractRegistry address:  0x2893719a88c0776684ffbaa10ee1c52460c41463
contractFeatures address:  0x0c80ae8ca2adc7b7fb50c4c4612e8e381365a2df
bancorFormula address:  0x2de6ce8d2f3a4a6f1cef8fb44fff8045cf485b77
bancorGasPriceLimit address:  0x8d00d7babad53cfe0cec7a291871dd657f09c79c
featureIds address:  0x5311e2acf85db065bfa8c6c8a4a84cc4c55cd830
whiteList address:  0x9a7343e13db895dc89e795a16cbbd032abe1076c
etherToken address:  0x2a5353ff19d7be372156402d629ddd99c3db9ea6
ring address:  0xa064427851d775e2c15121602a1658a882c55fb0
bancorConverter address:  0x5ea4819c2a5baf6fb975739df6bbb89d035ed6c9
bancorExchange address:  0x9f1a09fd24fecb546bded4b37eea2c06f270e8d6
registry address:  0x3fa1386c7c156af4fe1d75bed9909af9a467cd3a
auctionSettingIds address:  0x0f0811c9baa106b7efc03e854170187e7ce9cf15
atlantis address:  0x742f3cb2ed6b87e7b841d5d9513a4210c6b6a692
mysteriousTreasure address:  0x3e687743af32b67669ba0c7100e461cb2ab9f278
genesisHolder address:  0xbbfcba94d495e52f64a092952b2ee463e038d22f
claimBountyCalculator address:  0x81c321ac20af5a6a9dbba315e596fd33d9dc7b70
landGenesisData address:  0xcd553a260fe10ce615cffa6264dfafeb5a661bf9
clockAuction address:  0xc75cbdd763fc1093ec44da23c1835c396053fa95
Kton address:  0x06560120d57620e9a40083860f23145acf0e86a1
    ✓ [create-dsw-01], common people create auction (268ms)
    ✓ [create-dsw-02], common people create auction which already created (40ms)
    ✓ [create-dsw-03], common people use createAuction function (77ms)
    ✓ [create-dsw-04], genesisHolder create auction when land does not exist (79ms)
    ✓ [create-dsw-05], genesisHolder create auction (364ms)
    ✓ [create-dsw-06], genesisHolder create auction which already created (78ms)
    ✓ [create-dsw-07], genesisHolder create auction while msg.sender is not operator (75ms)
    ✓ [create-dsw-08], genesisHolder create auction which land is reserved but token is set to ring (89ms)
    ✓ [create-dsw-09], genesisHolder create auction and set auction.token to kton (385ms)
    ✓ [preparation for bid], create an auction which start time is in far future (399ms)
    ✓ [bid-dsw-01], bid for an auction which is not started (266ms)
    ✓ [bid-dsw-02], bid for an auction that does not exist (233ms)
    ✓ [bid-dsw-03], bid for an auction with another token (206ms)
    ✓ preparation for test [bid-dsw-04] (811ms)
seller ring before bid:  1e+23
seller ring after bid:  1.0009456e+23
seller ring change:  98499999999983620000
RING to seller:  94560000000001050000
RING to official:  3152000000000000000
RING to referer:  788000000016646100
    1) [bid-dsw-04], verify first bid

    Events emitted during test:
    ---------------------------

    Transfer(from: <indexed>, to: <indexed>, value: 100000000000000000000)
    Transfer(from: <indexed>, to: <indexed>, value: 1500000000000000000)
    Transfer(from: <indexed>, to: <indexed>, value: 94560000000000000000)
    Transfer(from: <indexed>, to: <indexed>, value: 788000000000000000)
    NewBid(tokenId: <indexed>, lastBidder: 0xf09237ace3075133cbcbd2ff50e3727a222e0112, lastReferer: 0x032d960fb656c51c17bfa8669baa7de67dc8541c, lastRecord: 98500000000000000000, tokenAddress: 0xa064427851d775e2c15121602a1658a882c55fb0, bidStartAt: 1539251814, returnToLastBidder: 0)
    ERC223Transfer(from: <indexed>, to: <indexed>, amount: 100000000000000000000, data: 0xffffffffffffffffffffffffffffffa800000000000000000000000000000004000000000000000000000000032d960fb656c51c17bfa8669baa7de67dc8541c)

    ---------------------------


  14 passing (13s)
  1 failing

  1) Contract: ClockAuction deployment
       [bid-dsw-04], verify first bid:
     AssertionError: expected false to equal 'in does not equal to balance.'
      at Context.it (test/ClockAuction.test.js:284:16)
      at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:118:7)

for example, we can see in Transfer event:

Transfer(from: <indexed>, to: <indexed>, value: 94560000000000000000)

but by subtracting the balance of seller before bidding from the balance of seller after bidding, we can see below print in terminal:

RING to seller:  94560000000001050000

the two result above apparently does not equal.

by printing seller's balance before and after the bid, we can see that this error is not caused by accuracy loss in javascript Arithmetic operations, instead, it comes from interacting with the contract.

the reason is still not found.