path: root/consensus/ethash/consensus_test.go

// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package ethash

import (
    "encoding/json"
    "math/big"
    "os"
    "path/filepath"
    "testing"

    "github.com/ethereum/go-ethereum/common/math"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/params"
)

type diffTest struct {
    ParentTimestamp    uint64
    ParentDifficulty   *big.Int
    CurrentTimestamp   uint64
    CurrentBlocknumber *big.Int
    CurrentDifficulty  *big.Int
}

func (d *diffTest) UnmarshalJSON(b []byte) (err error) {
    var ext struct {
        ParentTimestamp    string
        ParentDifficulty   string
        CurrentTimestamp   string
        CurrentBlocknumber string
        CurrentDifficulty  string
    }
    if err := json.Unmarshal(b, &ext); err != nil {
        return err
    }

    d.ParentTimestamp = math.MustParseUint64(ext.ParentTimestamp)
    d.ParentDifficulty = math.MustParseBig256(ext.ParentDifficulty)
    d.CurrentTimestamp = math.MustParseUint64(ext.CurrentTimestamp)
    d.CurrentBlocknumber = math.MustParseBig256(ext.CurrentBlocknumber)
    d.CurrentDifficulty = math.MustParseBig256(ext.CurrentDifficulty)

    return nil
}

func TestCalcDifficulty(t *testing.T) {
    file, err := os.Open(filepath.Join("..", "..", "tests", "testdata", "BasicTests", "difficulty.json"))
    if err != nil {
        t.Skip(err)
    }
    defer file.Close()

    tests := make(map[string]diffTest)
    err = json.NewDecoder(file).Decode(&tests)
    if err != nil {
        t.Fatal(err)
    }

    config := &params.ChainConfig{HomesteadBlock: big.NewInt(1150000)}

    for name, test := range tests {
        number := new(big.Int).Sub(test.CurrentBlocknumber, big.NewInt(1))
        diff := CalcDifficulty(config, test.CurrentTimestamp, &types.Header{
            Number:     number,
            Time:       new(big.Int).SetUint64(test.ParentTimestamp),
            Difficulty: test.ParentDifficulty,
        })
        if diff.Cmp(test.CurrentDifficulty) != 0 {
            t.Error(name, "failed. Expected", test.CurrentDifficulty, "and calculated", diff)
        }
    }
}