.. _difficulty_tests:

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难度测试
################################################################################

Found in ``\Basic Tests\difficulty*.json`` files. This tests are designed to just check the difficulty formula of a block.

difficulty = DIFFICULTY(currentBlockNumber, currentTimestamp, parentTimestamp, parentDifficulty)

described at [EIP2](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-2.mediawiki) point 4 with homestead changes.

So basically this .json tests are just to check how this function is calculated on different function parameters (parentDifficulty, currentNumber) in its extremum points. 

There are several test files:

``difficulty.json``
	Normal Frontier/Homestead chain difficulty tests defined manually
``difficultyFrontier.json``
	Same as above, but auto-generated tests
``difficultyMorden.json``
	Tests for testnetwork difficulty. (it has different homestead transition block)
``difficultyOlimpic.json``
	Olympic network. (no homestead)
``difficultyHomestead.json``
	Tests for homestead difficulty (regardless of the block number)
``difficultyCustomHomestead.json``
	Tests for homestead difficulty (regardless of the block number)

基本结构
--------------------------------------------------------------------------------
::

	{
		"difficultyTest" : {
			"parentTimestamp" : "42",
			"parentDifficulty" : "1000000",
			"currentTimestamp" : "43",
			"currentBlockNumber" : "42",
			"currentDifficulty" : "1000488"
		}
	}

字段功能
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* ``parentTimestamp`` - indicates the timestamp of a previous block
* ``parentDifficulty`` - indicates the difficulty of a previous block
* ``currentTimestamp`` - indicates the timestamp of a current block
* ``currentBlockNumber`` - indicates the number of a current block (previous block number = currentBlockNumber - 1)
* ``currentDifficulty`` - indicates the difficulty of a current block