go-ethereum: github.com/ethereum/go-ethereum/accounts/abi Index | Examples | Files | Directories

package abi

import "github.com/ethereum/go-ethereum/accounts/abi"

Package abi implements the Ethereum ABI (Application Binary Interface).

The Ethereum ABI is strongly typed, known at compile time and static. This ABI will handle basic type casting; unsigned to signed and visa versa. It does not handle slice casting such as unsigned slice to signed slice. Bit size type casting is also handled. ints with a bit size of 32 will be properly cast to int256, etc.

Index

Examples

Package Files

abi.go argument.go doc.go error.go event.go method.go numbers.go pack.go reflect.go type.go unpack.go

Constants

const (
    IntTy byte = iota
    UintTy
    BoolTy
    StringTy
    SliceTy
    ArrayTy
    TupleTy
    AddressTy
    FixedBytesTy
    BytesTy
    HashTy
    FixedPointTy
    FunctionTy
)

Type enumerator

Variables

var (
    // MaxUint256 is the maximum value that can be represented by a uint256
    MaxUint256 = new(big.Int).Sub(new(big.Int).Lsh(common.Big1, 256), common.Big1)
    // MaxInt256 is the maximum value that can be represented by a int256
    MaxInt256 = new(big.Int).Sub(new(big.Int).Lsh(common.Big1, 255), common.Big1)
)

func ReadFixedBytes Uses

func ReadFixedBytes(t Type, word []byte) (interface{}, error)

ReadFixedBytes uses reflection to create a fixed array to be read from

func ReadInteger Uses

func ReadInteger(typ byte, kind reflect.Kind, b []byte) interface{}

ReadInteger reads the integer based on its kind and returns the appropriate value

func ToCamelCase Uses

func ToCamelCase(input string) string

ToCamelCase converts an under-score string to a camel-case string

func U256 Uses

func U256(n *big.Int) []byte

U256 converts a big Int into a 256bit EVM number.

type ABI Uses

type ABI struct {
    Constructor Method
    Methods     map[string]Method
    Events      map[string]Event
}

The ABI holds information about a contract's context and available invokable methods. It will allow you to type check function calls and packs data accordingly.

func JSON Uses

func JSON(reader io.Reader) (ABI, error)

JSON returns a parsed ABI interface and error if it failed.

Code:

package main

import (
    "bytes"
    "encoding/hex"
    "fmt"
    "math/big"
    "reflect"
    "strings"
    "testing"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
)

const jsondata = `
[
	{ "type" : "function", "name" : "balance", "constant" : true },
	{ "type" : "function", "name" : "send", "constant" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
]`

const jsondata2 = `
[
	{ "type" : "function", "name" : "balance", "constant" : true },
	{ "type" : "function", "name" : "send", "constant" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
	{ "type" : "function", "name" : "test", "constant" : false, "inputs" : [ { "name" : "number", "type" : "uint32" } ] },
	{ "type" : "function", "name" : "string", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "string" } ] },
	{ "type" : "function", "name" : "bool", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "bool" } ] },
	{ "type" : "function", "name" : "address", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "address" } ] },
	{ "type" : "function", "name" : "uint64[2]", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[2]" } ] },
	{ "type" : "function", "name" : "uint64[]", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[]" } ] },
	{ "type" : "function", "name" : "foo", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" } ] },
	{ "type" : "function", "name" : "bar", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" }, { "name" : "string", "type" : "uint16" } ] },
	{ "type" : "function", "name" : "slice", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32[2]" } ] },
	{ "type" : "function", "name" : "slice256", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint256[2]" } ] },
	{ "type" : "function", "name" : "sliceAddress", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "address[]" } ] },
	{ "type" : "function", "name" : "sliceMultiAddress", "constant" : false, "inputs" : [ { "name" : "a", "type" : "address[]" }, { "name" : "b", "type" : "address[]" } ] },
	{ "type" : "function", "name" : "nestedArray", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint256[2][2]" }, { "name" : "b", "type" : "address[]" } ] },
	{ "type" : "function", "name" : "nestedArray2", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint8[][2]" } ] },
	{ "type" : "function", "name" : "nestedSlice", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint8[][]" } ] }
]`

func TestReader(t *testing.T) {
    Uint256, _ := NewType("uint256", "", nil)
    exp := ABI{
        Methods: map[string]Method{
            "balance": {
                "balance", "balance", true, nil, nil,
            },
            "send": {
                "send", "send", false, []Argument{
                    {"amount", Uint256, false},
                }, nil,
            },
        },
    }

    abi, err := JSON(strings.NewReader(jsondata))
    if err != nil {
        t.Error(err)
    }

    // deep equal fails for some reason
    for name, expM := range exp.Methods {
        gotM, exist := abi.Methods[name]
        if !exist {
            t.Errorf("Missing expected method %v", name)
        }
        if !reflect.DeepEqual(gotM, expM) {
            t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
        }
    }

    for name, gotM := range abi.Methods {
        expM, exist := exp.Methods[name]
        if !exist {
            t.Errorf("Found extra method %v", name)
        }
        if !reflect.DeepEqual(gotM, expM) {
            t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
        }
    }
}

func TestTestNumbers(t *testing.T) {
    abi, err := JSON(strings.NewReader(jsondata2))
    if err != nil {
        t.Fatal(err)
    }

    if _, err := abi.Pack("balance"); err != nil {
        t.Error(err)
    }

    if _, err := abi.Pack("balance", 1); err == nil {
        t.Error("expected error for balance(1)")
    }

    if _, err := abi.Pack("doesntexist", nil); err == nil {
        t.Errorf("doesntexist shouldn't exist")
    }

    if _, err := abi.Pack("doesntexist", 1); err == nil {
        t.Errorf("doesntexist(1) shouldn't exist")
    }

    if _, err := abi.Pack("send", big.NewInt(1000)); err != nil {
        t.Error(err)
    }

    i := new(int)
    *i = 1000
    if _, err := abi.Pack("send", i); err == nil {
        t.Errorf("expected send( ptr ) to throw, requires *big.Int instead of *int")
    }

    if _, err := abi.Pack("test", uint32(1000)); err != nil {
        t.Error(err)
    }
}

func TestTestString(t *testing.T) {
    abi, err := JSON(strings.NewReader(jsondata2))
    if err != nil {
        t.Fatal(err)
    }

    if _, err := abi.Pack("string", "hello world"); err != nil {
        t.Error(err)
    }
}

func TestTestBool(t *testing.T) {
    abi, err := JSON(strings.NewReader(jsondata2))
    if err != nil {
        t.Fatal(err)
    }

    if _, err := abi.Pack("bool", true); err != nil {
        t.Error(err)
    }
}

func TestTestSlice(t *testing.T) {
    abi, err := JSON(strings.NewReader(jsondata2))
    if err != nil {
        t.Fatal(err)
    }
    slice := make([]uint64, 2)
    if _, err := abi.Pack("uint64[2]", slice); err != nil {
        t.Error(err)
    }
    if _, err := abi.Pack("uint64[]", slice); err != nil {
        t.Error(err)
    }
}

func TestMethodSignature(t *testing.T) {
    String, _ := NewType("string", "", nil)
    m := Method{"foo", "foo", false, []Argument{{"bar", String, false}, {"baz", String, false}}, nil}
    exp := "foo(string,string)"
    if m.Sig() != exp {
        t.Error("signature mismatch", exp, "!=", m.Sig())
    }

    idexp := crypto.Keccak256([]byte(exp))[:4]
    if !bytes.Equal(m.ID(), idexp) {
        t.Errorf("expected ids to match %x != %x", m.ID(), idexp)
    }

    uintt, _ := NewType("uint256", "", nil)
    m = Method{"foo", "foo", false, []Argument{{"bar", uintt, false}}, nil}
    exp = "foo(uint256)"
    if m.Sig() != exp {
        t.Error("signature mismatch", exp, "!=", m.Sig())
    }

    // Method with tuple arguments
    s, _ := NewType("tuple", "", []ArgumentMarshaling{
        {Name: "a", Type: "int256"},
        {Name: "b", Type: "int256[]"},
        {Name: "c", Type: "tuple[]", Components: []ArgumentMarshaling{
            {Name: "x", Type: "int256"},
            {Name: "y", Type: "int256"},
        }},
        {Name: "d", Type: "tuple[2]", Components: []ArgumentMarshaling{
            {Name: "x", Type: "int256"},
            {Name: "y", Type: "int256"},
        }},
    })
    m = Method{"foo", "foo", false, []Argument{{"s", s, false}, {"bar", String, false}}, nil}
    exp = "foo((int256,int256[],(int256,int256)[],(int256,int256)[2]),string)"
    if m.Sig() != exp {
        t.Error("signature mismatch", exp, "!=", m.Sig())
    }
}

func TestOverloadedMethodSignature(t *testing.T) {
    json := `[{"constant":true,"inputs":[{"name":"i","type":"uint256"},{"name":"j","type":"uint256"}],"name":"foo","outputs":[],"payable":false,"stateMutability":"pure","type":"function"},{"constant":true,"inputs":[{"name":"i","type":"uint256"}],"name":"foo","outputs":[],"payable":false,"stateMutability":"pure","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"i","type":"uint256"}],"name":"bar","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"i","type":"uint256"},{"indexed":false,"name":"j","type":"uint256"}],"name":"bar","type":"event"}]`
    abi, err := JSON(strings.NewReader(json))
    if err != nil {
        t.Fatal(err)
    }
    check := func(name string, expect string, method bool) {
        if method {
            if abi.Methods[name].Sig() != expect {
                t.Fatalf("The signature of overloaded method mismatch, want %s, have %s", expect, abi.Methods[name].Sig())
            }
        } else {
            if abi.Events[name].Sig() != expect {
                t.Fatalf("The signature of overloaded event mismatch, want %s, have %s", expect, abi.Events[name].Sig())
            }
        }
    }
    check("foo", "foo(uint256,uint256)", true)
    check("foo0", "foo(uint256)", true)
    check("bar", "bar(uint256)", false)
    check("bar0", "bar(uint256,uint256)", false)
}

func TestMultiPack(t *testing.T) {
    abi, err := JSON(strings.NewReader(jsondata2))
    if err != nil {
        t.Fatal(err)
    }

    sig := crypto.Keccak256([]byte("bar(uint32,uint16)"))[:4]
    sig = append(sig, make([]byte, 64)...)
    sig[35] = 10
    sig[67] = 11

    packed, err := abi.Pack("bar", uint32(10), uint16(11))
    if err != nil {
        t.Fatal(err)
    }
    if !bytes.Equal(packed, sig) {
        t.Errorf("expected %x got %x", sig, packed)
    }
}

func main() {
    const definition = `[{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"isBar","outputs":[{"name":"","type":"bool"}],"type":"function"}]`

    abi, err := JSON(strings.NewReader(definition))
    if err != nil {
        panic(err)
    }
    out, err := abi.Pack("isBar", common.HexToAddress("01"))
    if err != nil {
        panic(err)
    }

    fmt.Printf("%x\n", out)
}

func TestInputVariableInputLength(t *testing.T) {
    const definition = `[
	{ "type" : "function", "name" : "strOne", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" } ] },
	{ "type" : "function", "name" : "bytesOne", "constant" : true, "inputs" : [ { "name" : "str", "type" : "bytes" } ] },
	{ "type" : "function", "name" : "strTwo", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "str1", "type" : "string" } ] }
	]`

    abi, err := JSON(strings.NewReader(definition))
    if err != nil {
        t.Fatal(err)
    }

    // test one string
    strin := "hello world"
    strpack, err := abi.Pack("strOne", strin)
    if err != nil {
        t.Error(err)
    }

    offset := make([]byte, 32)
    offset[31] = 32
    length := make([]byte, 32)
    length[31] = byte(len(strin))
    value := common.RightPadBytes([]byte(strin), 32)
    exp := append(offset, append(length, value...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    strpack = strpack[4:]
    if !bytes.Equal(strpack, exp) {
        t.Errorf("expected %x, got %x\n", exp, strpack)
    }

    // test one bytes
    btspack, err := abi.Pack("bytesOne", []byte(strin))
    if err != nil {
        t.Error(err)
    }
    // ignore first 4 bytes of the output. This is the function identifier
    btspack = btspack[4:]
    if !bytes.Equal(btspack, exp) {
        t.Errorf("expected %x, got %x\n", exp, btspack)
    }

    //  test two strings
    str1 := "hello"
    str2 := "world"
    str2pack, err := abi.Pack("strTwo", str1, str2)
    if err != nil {
        t.Error(err)
    }

    offset1 := make([]byte, 32)
    offset1[31] = 64
    length1 := make([]byte, 32)
    length1[31] = byte(len(str1))
    value1 := common.RightPadBytes([]byte(str1), 32)

    offset2 := make([]byte, 32)
    offset2[31] = 128
    length2 := make([]byte, 32)
    length2[31] = byte(len(str2))
    value2 := common.RightPadBytes([]byte(str2), 32)

    exp2 := append(offset1, offset2...)
    exp2 = append(exp2, append(length1, value1...)...)
    exp2 = append(exp2, append(length2, value2...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    str2pack = str2pack[4:]
    if !bytes.Equal(str2pack, exp2) {
        t.Errorf("expected %x, got %x\n", exp, str2pack)
    }

    // test two strings, first > 32, second < 32
    str1 = strings.Repeat("a", 33)
    str2pack, err = abi.Pack("strTwo", str1, str2)
    if err != nil {
        t.Error(err)
    }

    offset1 = make([]byte, 32)
    offset1[31] = 64
    length1 = make([]byte, 32)
    length1[31] = byte(len(str1))
    value1 = common.RightPadBytes([]byte(str1), 64)
    offset2[31] = 160

    exp2 = append(offset1, offset2...)
    exp2 = append(exp2, append(length1, value1...)...)
    exp2 = append(exp2, append(length2, value2...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    str2pack = str2pack[4:]
    if !bytes.Equal(str2pack, exp2) {
        t.Errorf("expected %x, got %x\n", exp, str2pack)
    }

    // test two strings, first > 32, second >32
    str1 = strings.Repeat("a", 33)
    str2 = strings.Repeat("a", 33)
    str2pack, err = abi.Pack("strTwo", str1, str2)
    if err != nil {
        t.Error(err)
    }

    offset1 = make([]byte, 32)
    offset1[31] = 64
    length1 = make([]byte, 32)
    length1[31] = byte(len(str1))
    value1 = common.RightPadBytes([]byte(str1), 64)

    offset2 = make([]byte, 32)
    offset2[31] = 160
    length2 = make([]byte, 32)
    length2[31] = byte(len(str2))
    value2 = common.RightPadBytes([]byte(str2), 64)

    exp2 = append(offset1, offset2...)
    exp2 = append(exp2, append(length1, value1...)...)
    exp2 = append(exp2, append(length2, value2...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    str2pack = str2pack[4:]
    if !bytes.Equal(str2pack, exp2) {
        t.Errorf("expected %x, got %x\n", exp, str2pack)
    }
}

func TestInputFixedArrayAndVariableInputLength(t *testing.T) {
    const definition = `[
	{ "type" : "function", "name" : "fixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr", "type" : "uint256[2]" } ] },
	{ "type" : "function", "name" : "fixedArrBytes", "constant" : true, "inputs" : [ { "name" : "str", "type" : "bytes" }, { "name" : "fixedArr", "type" : "uint256[2]" } ] },
    { "type" : "function", "name" : "mixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr", "type": "uint256[2]" }, { "name" : "dynArr", "type": "uint256[]" } ] },
    { "type" : "function", "name" : "doubleFixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr1", "type": "uint256[2]" }, { "name" : "fixedArr2", "type": "uint256[3]" } ] },
    { "type" : "function", "name" : "multipleMixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr1", "type": "uint256[2]" }, { "name" : "dynArr", "type" : "uint256[]" }, { "name" : "fixedArr2", "type" : "uint256[3]" } ] }
	]`

    abi, err := JSON(strings.NewReader(definition))
    if err != nil {
        t.Error(err)
    }

    // test string, fixed array uint256[2]
    strin := "hello world"
    arrin := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
    fixedArrStrPack, err := abi.Pack("fixedArrStr", strin, arrin)
    if err != nil {
        t.Error(err)
    }

    // generate expected output
    offset := make([]byte, 32)
    offset[31] = 96
    length := make([]byte, 32)
    length[31] = byte(len(strin))
    strvalue := common.RightPadBytes([]byte(strin), 32)
    arrinvalue1 := common.LeftPadBytes(arrin[0].Bytes(), 32)
    arrinvalue2 := common.LeftPadBytes(arrin[1].Bytes(), 32)
    exp := append(offset, arrinvalue1...)
    exp = append(exp, arrinvalue2...)
    exp = append(exp, append(length, strvalue...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    fixedArrStrPack = fixedArrStrPack[4:]
    if !bytes.Equal(fixedArrStrPack, exp) {
        t.Errorf("expected %x, got %x\n", exp, fixedArrStrPack)
    }

    // test byte array, fixed array uint256[2]
    bytesin := []byte(strin)
    arrin = [2]*big.Int{big.NewInt(1), big.NewInt(2)}
    fixedArrBytesPack, err := abi.Pack("fixedArrBytes", bytesin, arrin)
    if err != nil {
        t.Error(err)
    }

    // generate expected output
    offset = make([]byte, 32)
    offset[31] = 96
    length = make([]byte, 32)
    length[31] = byte(len(strin))
    strvalue = common.RightPadBytes([]byte(strin), 32)
    arrinvalue1 = common.LeftPadBytes(arrin[0].Bytes(), 32)
    arrinvalue2 = common.LeftPadBytes(arrin[1].Bytes(), 32)
    exp = append(offset, arrinvalue1...)
    exp = append(exp, arrinvalue2...)
    exp = append(exp, append(length, strvalue...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    fixedArrBytesPack = fixedArrBytesPack[4:]
    if !bytes.Equal(fixedArrBytesPack, exp) {
        t.Errorf("expected %x, got %x\n", exp, fixedArrBytesPack)
    }

    // test string, fixed array uint256[2], dynamic array uint256[]
    strin = "hello world"
    fixedarrin := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
    dynarrin := []*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
    mixedArrStrPack, err := abi.Pack("mixedArrStr", strin, fixedarrin, dynarrin)
    if err != nil {
        t.Error(err)
    }

    // generate expected output
    stroffset := make([]byte, 32)
    stroffset[31] = 128
    strlength := make([]byte, 32)
    strlength[31] = byte(len(strin))
    strvalue = common.RightPadBytes([]byte(strin), 32)
    fixedarrinvalue1 := common.LeftPadBytes(fixedarrin[0].Bytes(), 32)
    fixedarrinvalue2 := common.LeftPadBytes(fixedarrin[1].Bytes(), 32)
    dynarroffset := make([]byte, 32)
    dynarroffset[31] = byte(160 + ((len(strin)/32)+1)*32)
    dynarrlength := make([]byte, 32)
    dynarrlength[31] = byte(len(dynarrin))
    dynarrinvalue1 := common.LeftPadBytes(dynarrin[0].Bytes(), 32)
    dynarrinvalue2 := common.LeftPadBytes(dynarrin[1].Bytes(), 32)
    dynarrinvalue3 := common.LeftPadBytes(dynarrin[2].Bytes(), 32)
    exp = append(stroffset, fixedarrinvalue1...)
    exp = append(exp, fixedarrinvalue2...)
    exp = append(exp, dynarroffset...)
    exp = append(exp, append(strlength, strvalue...)...)
    dynarrarg := append(dynarrlength, dynarrinvalue1...)
    dynarrarg = append(dynarrarg, dynarrinvalue2...)
    dynarrarg = append(dynarrarg, dynarrinvalue3...)
    exp = append(exp, dynarrarg...)

    // ignore first 4 bytes of the output. This is the function identifier
    mixedArrStrPack = mixedArrStrPack[4:]
    if !bytes.Equal(mixedArrStrPack, exp) {
        t.Errorf("expected %x, got %x\n", exp, mixedArrStrPack)
    }

    // test string, fixed array uint256[2], fixed array uint256[3]
    strin = "hello world"
    fixedarrin1 := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
    fixedarrin2 := [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
    doubleFixedArrStrPack, err := abi.Pack("doubleFixedArrStr", strin, fixedarrin1, fixedarrin2)
    if err != nil {
        t.Error(err)
    }

    // generate expected output
    stroffset = make([]byte, 32)
    stroffset[31] = 192
    strlength = make([]byte, 32)
    strlength[31] = byte(len(strin))
    strvalue = common.RightPadBytes([]byte(strin), 32)
    fixedarrin1value1 := common.LeftPadBytes(fixedarrin1[0].Bytes(), 32)
    fixedarrin1value2 := common.LeftPadBytes(fixedarrin1[1].Bytes(), 32)
    fixedarrin2value1 := common.LeftPadBytes(fixedarrin2[0].Bytes(), 32)
    fixedarrin2value2 := common.LeftPadBytes(fixedarrin2[1].Bytes(), 32)
    fixedarrin2value3 := common.LeftPadBytes(fixedarrin2[2].Bytes(), 32)
    exp = append(stroffset, fixedarrin1value1...)
    exp = append(exp, fixedarrin1value2...)
    exp = append(exp, fixedarrin2value1...)
    exp = append(exp, fixedarrin2value2...)
    exp = append(exp, fixedarrin2value3...)
    exp = append(exp, append(strlength, strvalue...)...)

    // ignore first 4 bytes of the output. This is the function identifier
    doubleFixedArrStrPack = doubleFixedArrStrPack[4:]
    if !bytes.Equal(doubleFixedArrStrPack, exp) {
        t.Errorf("expected %x, got %x\n", exp, doubleFixedArrStrPack)
    }

    // test string, fixed array uint256[2], dynamic array uint256[], fixed array uint256[3]
    strin = "hello world"
    fixedarrin1 = [2]*big.Int{big.NewInt(1), big.NewInt(2)}
    dynarrin = []*big.Int{big.NewInt(1), big.NewInt(2)}
    fixedarrin2 = [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
    multipleMixedArrStrPack, err := abi.Pack("multipleMixedArrStr", strin, fixedarrin1, dynarrin, fixedarrin2)
    if err != nil {
        t.Error(err)
    }

    // generate expected output
    stroffset = make([]byte, 32)
    stroffset[31] = 224
    strlength = make([]byte, 32)
    strlength[31] = byte(len(strin))
    strvalue = common.RightPadBytes([]byte(strin), 32)
    fixedarrin1value1 = common.LeftPadBytes(fixedarrin1[0].Bytes(), 32)
    fixedarrin1value2 = common.LeftPadBytes(fixedarrin1[1].Bytes(), 32)
    dynarroffset = U256(big.NewInt(int64(256 + ((len(strin)/32)+1)*32)))
    dynarrlength = make([]byte, 32)
    dynarrlength[31] = byte(len(dynarrin))
    dynarrinvalue1 = common.LeftPadBytes(dynarrin[0].Bytes(), 32)
    dynarrinvalue2 = common.LeftPadBytes(dynarrin[1].Bytes(), 32)
    fixedarrin2value1 = common.LeftPadBytes(fixedarrin2[0].Bytes(), 32)
    fixedarrin2value2 = common.LeftPadBytes(fixedarrin2[1].Bytes(), 32)
    fixedarrin2value3 = common.LeftPadBytes(fixedarrin2[2].Bytes(), 32)
    exp = append(stroffset, fixedarrin1value1...)
    exp = append(exp, fixedarrin1value2...)
    exp = append(exp, dynarroffset...)
    exp = append(exp, fixedarrin2value1...)
    exp = append(exp, fixedarrin2value2...)
    exp = append(exp, fixedarrin2value3...)
    exp = append(exp, append(strlength, strvalue...)...)
    dynarrarg = append(dynarrlength, dynarrinvalue1...)
    dynarrarg = append(dynarrarg, dynarrinvalue2...)
    exp = append(exp, dynarrarg...)

    // ignore first 4 bytes of the output. This is the function identifier
    multipleMixedArrStrPack = multipleMixedArrStrPack[4:]
    if !bytes.Equal(multipleMixedArrStrPack, exp) {
        t.Errorf("expected %x, got %x\n", exp, multipleMixedArrStrPack)
    }
}

func TestDefaultFunctionParsing(t *testing.T) {
    const definition = `[{ "name" : "balance" }]`

    abi, err := JSON(strings.NewReader(definition))
    if err != nil {
        t.Fatal(err)
    }

    if _, ok := abi.Methods["balance"]; !ok {
        t.Error("expected 'balance' to be present")
    }
}

func TestBareEvents(t *testing.T) {
    const definition = `[
	{ "type" : "event", "name" : "balance" },
	{ "type" : "event", "name" : "anon", "anonymous" : true},
	{ "type" : "event", "name" : "args", "inputs" : [{ "indexed":false, "name":"arg0", "type":"uint256" }, { "indexed":true, "name":"arg1", "type":"address" }] },
	{ "type" : "event", "name" : "tuple", "inputs" : [{ "indexed":false, "name":"t", "type":"tuple", "components":[{"name":"a", "type":"uint256"}] }, { "indexed":true, "name":"arg1", "type":"address" }] }
	]`

    arg0, _ := NewType("uint256", "", nil)
    arg1, _ := NewType("address", "", nil)
    tuple, _ := NewType("tuple", "", []ArgumentMarshaling{{Name: "a", Type: "uint256"}})

    expectedEvents := map[string]struct {
        Anonymous bool
        Args      []Argument
    }{
        "balance": {false, nil},
        "anon":    {true, nil},
        "args": {false, []Argument{
            {Name: "arg0", Type: arg0, Indexed: false},
            {Name: "arg1", Type: arg1, Indexed: true},
        }},
        "tuple": {false, []Argument{
            {Name: "t", Type: tuple, Indexed: false},
            {Name: "arg1", Type: arg1, Indexed: true},
        }},
    }

    abi, err := JSON(strings.NewReader(definition))
    if err != nil {
        t.Fatal(err)
    }

    if len(abi.Events) != len(expectedEvents) {
        t.Fatalf("invalid number of events after parsing, want %d, got %d", len(expectedEvents), len(abi.Events))
    }

    for name, exp := range expectedEvents {
        got, ok := abi.Events[name]
        if !ok {
            t.Errorf("could not found event %s", name)
            continue
        }
        if got.Anonymous != exp.Anonymous {
            t.Errorf("invalid anonymous indication for event %s, want %v, got %v", name, exp.Anonymous, got.Anonymous)
        }
        if len(got.Inputs) != len(exp.Args) {
            t.Errorf("invalid number of args, want %d, got %d", len(exp.Args), len(got.Inputs))
            continue
        }
        for i, arg := range exp.Args {
            if arg.Name != got.Inputs[i].Name {
                t.Errorf("events[%s].Input[%d] has an invalid name, want %s, got %s", name, i, arg.Name, got.Inputs[i].Name)
            }
            if arg.Indexed != got.Inputs[i].Indexed {
                t.Errorf("events[%s].Input[%d] has an invalid indexed indication, want %v, got %v", name, i, arg.Indexed, got.Inputs[i].Indexed)
            }
            if arg.Type.T != got.Inputs[i].Type.T {
                t.Errorf("events[%s].Input[%d] has an invalid type, want %x, got %x", name, i, arg.Type.T, got.Inputs[i].Type.T)
            }
        }
    }
}

// TestUnpackEvent is based on this contract:
//    contract T {
//      event received(address sender, uint amount, bytes memo);
//      event receivedAddr(address sender);
//      function receive(bytes memo) external payable {
//        received(msg.sender, msg.value, memo);
//        receivedAddr(msg.sender);
//      }
//    }
// When receive("X") is called with sender 0x00... and value 1, it produces this tx receipt:
//   receipt{status=1 cgas=23949 bloom=00000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000040200000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 logs=[log: b6818c8064f645cd82d99b59a1a267d6d61117ef [75fd880d39c1daf53b6547ab6cb59451fc6452d27caa90e5b6649dd8293b9eed] 000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158 9ae378b6d4409eada347a5dc0c180f186cb62dc68fcc0f043425eb917335aa28 0 95d429d309bb9d753954195fe2d69bd140b4ae731b9b5b605c34323de162cf00 0]}
func TestUnpackEvent(t *testing.T) {
    const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
    abi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }

    const hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
    data, err := hex.DecodeString(hexdata)
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }

    type ReceivedEvent struct {
        Sender common.Address
        Amount *big.Int
        Memo   []byte
    }
    var ev ReceivedEvent

    err = abi.Unpack(&ev, "received", data)
    if err != nil {
        t.Error(err)
    }

    type ReceivedAddrEvent struct {
        Sender common.Address
    }
    var receivedAddrEv ReceivedAddrEvent
    err = abi.Unpack(&receivedAddrEv, "receivedAddr", data)
    if err != nil {
        t.Error(err)
    }
}

func TestUnpackEventIntoMap(t *testing.T) {
    const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
    abi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }

    const hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
    data, err := hex.DecodeString(hexdata)
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }

    receivedMap := map[string]interface{}{}
    expectedReceivedMap := map[string]interface{}{
        "sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
        "amount": big.NewInt(1),
        "memo":   []byte{88},
    }
    if err := abi.UnpackIntoMap(receivedMap, "received", data); err != nil {
        t.Error(err)
    }
    if len(receivedMap) != 3 {
        t.Error("unpacked `received` map expected to have length 3")
    }
    if receivedMap["sender"] != expectedReceivedMap["sender"] {
        t.Error("unpacked `received` map does not match expected map")
    }
    if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
        t.Error("unpacked `received` map does not match expected map")
    }
    if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
        t.Error("unpacked `received` map does not match expected map")
    }

    receivedAddrMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(receivedAddrMap, "receivedAddr", data); err != nil {
        t.Error(err)
    }
    if len(receivedAddrMap) != 1 {
        t.Error("unpacked `receivedAddr` map expected to have length 1")
    }
    if receivedAddrMap["sender"] != expectedReceivedMap["sender"] {
        t.Error("unpacked `receivedAddr` map does not match expected map")
    }
}

func TestUnpackMethodIntoMap(t *testing.T) {
    const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[],"name":"send","outputs":[{"name":"amount","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"addr","type":"address"}],"name":"get","outputs":[{"name":"hash","type":"bytes"}],"payable":true,"stateMutability":"payable","type":"function"}]`
    abi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    const hexdata = `00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000015800000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000158000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000001580000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000015800000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000158`
    data, err := hex.DecodeString(hexdata)
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 != 0 {
        t.Errorf("len(data) is %d, want a multiple of 32", len(data))
    }

    // Tests a method with no outputs
    receiveMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(receiveMap, "receive", data); err != nil {
        t.Error(err)
    }
    if len(receiveMap) > 0 {
        t.Error("unpacked `receive` map expected to have length 0")
    }

    // Tests a method with only outputs
    sendMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(sendMap, "send", data); err != nil {
        t.Error(err)
    }
    if len(sendMap) != 1 {
        t.Error("unpacked `send` map expected to have length 1")
    }
    if sendMap["amount"].(*big.Int).Cmp(big.NewInt(1)) != 0 {
        t.Error("unpacked `send` map expected `amount` value of 1")
    }

    // Tests a method with outputs and inputs
    getMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(getMap, "get", data); err != nil {
        t.Error(err)
    }
    if len(getMap) != 1 {
        t.Error("unpacked `get` map expected to have length 1")
    }
    expectedBytes := []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0}
    if !bytes.Equal(getMap["hash"].([]byte), expectedBytes) {
        t.Errorf("unpacked `get` map expected `hash` value of %v", expectedBytes)
    }
}

func TestUnpackIntoMapNamingConflict(t *testing.T) {
    // Two methods have the same name
    var abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"get","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[],"name":"send","outputs":[{"name":"amount","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"addr","type":"address"}],"name":"get","outputs":[{"name":"hash","type":"bytes"}],"payable":true,"stateMutability":"payable","type":"function"}]`
    abi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    var hexdata = `00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
    data, err := hex.DecodeString(hexdata)
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }
    getMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(getMap, "get", data); err == nil {
        t.Error("naming conflict between two methods; error expected")
    }

    // Two events have the same name
    abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"received","type":"event"}]`
    abi, err = JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
    data, err = hex.DecodeString(hexdata)
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }
    receivedMap := map[string]interface{}{}
    if err = abi.UnpackIntoMap(receivedMap, "received", data); err != nil {
        t.Error("naming conflict between two events; no error expected")
    }

    // Method and event have the same name
    abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"received","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
    abi, err = JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }
    if err = abi.UnpackIntoMap(receivedMap, "received", data); err == nil {
        t.Error("naming conflict between an event and a method; error expected")
    }

    // Conflict is case sensitive
    abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"received","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"Received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
    abi, err = JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    if len(data)%32 == 0 {
        t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
    }
    expectedReceivedMap := map[string]interface{}{
        "sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
        "amount": big.NewInt(1),
        "memo":   []byte{88},
    }
    if err = abi.UnpackIntoMap(receivedMap, "Received", data); err != nil {
        t.Error(err)
    }
    if len(receivedMap) != 3 {
        t.Error("unpacked `received` map expected to have length 3")
    }
    if receivedMap["sender"] != expectedReceivedMap["sender"] {
        t.Error("unpacked `received` map does not match expected map")
    }
    if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
        t.Error("unpacked `received` map does not match expected map")
    }
    if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
        t.Error("unpacked `received` map does not match expected map")
    }
}

func TestABI_MethodById(t *testing.T) {
    const abiJSON = `[
		{"type":"function","name":"receive","constant":false,"inputs":[{"name":"memo","type":"bytes"}],"outputs":[],"payable":true,"stateMutability":"payable"},
		{"type":"event","name":"received","anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}]},
		{"type":"function","name":"fixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"}]},
		{"type":"function","name":"fixedArrBytes","constant":true,"inputs":[{"name":"str","type":"bytes"},{"name":"fixedArr","type":"uint256[2]"}]},
		{"type":"function","name":"mixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"}]},
		{"type":"function","name":"doubleFixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"fixedArr2","type":"uint256[3]"}]},
		{"type":"function","name":"multipleMixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"},{"name":"fixedArr2","type":"uint256[3]"}]},
		{"type":"function","name":"balance","constant":true},
		{"type":"function","name":"send","constant":false,"inputs":[{"name":"amount","type":"uint256"}]},
		{"type":"function","name":"test","constant":false,"inputs":[{"name":"number","type":"uint32"}]},
		{"type":"function","name":"string","constant":false,"inputs":[{"name":"inputs","type":"string"}]},
		{"type":"function","name":"bool","constant":false,"inputs":[{"name":"inputs","type":"bool"}]},
		{"type":"function","name":"address","constant":false,"inputs":[{"name":"inputs","type":"address"}]},
		{"type":"function","name":"uint64[2]","constant":false,"inputs":[{"name":"inputs","type":"uint64[2]"}]},
		{"type":"function","name":"uint64[]","constant":false,"inputs":[{"name":"inputs","type":"uint64[]"}]},
		{"type":"function","name":"foo","constant":false,"inputs":[{"name":"inputs","type":"uint32"}]},
		{"type":"function","name":"bar","constant":false,"inputs":[{"name":"inputs","type":"uint32"},{"name":"string","type":"uint16"}]},
		{"type":"function","name":"_slice","constant":false,"inputs":[{"name":"inputs","type":"uint32[2]"}]},
		{"type":"function","name":"__slice256","constant":false,"inputs":[{"name":"inputs","type":"uint256[2]"}]},
		{"type":"function","name":"sliceAddress","constant":false,"inputs":[{"name":"inputs","type":"address[]"}]},
		{"type":"function","name":"sliceMultiAddress","constant":false,"inputs":[{"name":"a","type":"address[]"},{"name":"b","type":"address[]"}]}
	]
`
    abi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    for name, m := range abi.Methods {
        a := fmt.Sprintf("%v", m)
        m2, err := abi.MethodById(m.ID())
        if err != nil {
            t.Fatalf("Failed to look up ABI method: %v", err)
        }
        b := fmt.Sprintf("%v", m2)
        if a != b {
            t.Errorf("Method %v (id %x) not 'findable' by id in ABI", name, m.ID())
        }
    }
    // Also test empty
    if _, err := abi.MethodById([]byte{0x00}); err == nil {
        t.Errorf("Expected error, too short to decode data")
    }
    if _, err := abi.MethodById([]byte{}); err == nil {
        t.Errorf("Expected error, too short to decode data")
    }
    if _, err := abi.MethodById(nil); err == nil {
        t.Errorf("Expected error, nil is short to decode data")
    }
}

func TestABI_EventById(t *testing.T) {
    tests := []struct {
        name  string
        json  string
        event string
    }{
        {
            name: "",
            json: `[
			{"type":"event","name":"received","anonymous":false,"inputs":[
				{"indexed":false,"name":"sender","type":"address"},
				{"indexed":false,"name":"amount","type":"uint256"},
				{"indexed":false,"name":"memo","type":"bytes"}
				]
			}]`,
            event: "received(address,uint256,bytes)",
        }, {
            name: "",
            json: `[
				{ "constant": true, "inputs": [], "name": "name", "outputs": [ { "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "constant": false, "inputs": [ { "name": "_spender", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "approve", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" },
				{ "constant": true, "inputs": [], "name": "totalSupply", "outputs": [ { "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "constant": false, "inputs": [ { "name": "_from", "type": "address" }, { "name": "_to", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "transferFrom", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" },
				{ "constant": true, "inputs": [], "name": "decimals", "outputs": [ { "name": "", "type": "uint8" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "constant": true, "inputs": [ { "name": "_owner", "type": "address" } ], "name": "balanceOf", "outputs": [ { "name": "balance", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "constant": true, "inputs": [], "name": "symbol", "outputs": [ { "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "constant": false, "inputs": [ { "name": "_to", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "transfer", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" },
				{ "constant": true, "inputs": [ { "name": "_owner", "type": "address" }, { "name": "_spender", "type": "address" } ], "name": "allowance", "outputs": [ { "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" },
				{ "payable": true, "stateMutability": "payable", "type": "fallback" },
				{ "anonymous": false, "inputs": [ { "indexed": true, "name": "owner", "type": "address" }, { "indexed": true, "name": "spender", "type": "address" }, { "indexed": false, "name": "value", "type": "uint256" } ], "name": "Approval", "type": "event" },
				{ "anonymous": false, "inputs": [ { "indexed": true, "name": "from", "type": "address" }, { "indexed": true, "name": "to", "type": "address" }, { "indexed": false, "name": "value", "type": "uint256" } ], "name": "Transfer", "type": "event" }
			]`,
            event: "Transfer(address,address,uint256)",
        },
    }

    for testnum, test := range tests {
        abi, err := JSON(strings.NewReader(test.json))
        if err != nil {
            t.Error(err)
        }

        topic := test.event
        topicID := crypto.Keccak256Hash([]byte(topic))

        event, err := abi.EventByID(topicID)
        if err != nil {
            t.Fatalf("Failed to look up ABI method: %v, test #%d", err, testnum)
        }
        if event == nil {
            t.Errorf("We should find a event for topic %s, test #%d", topicID.Hex(), testnum)
        }

        if event.ID() != topicID {
            t.Errorf("Event id %s does not match topic %s, test #%d", event.ID().Hex(), topicID.Hex(), testnum)
        }

        unknowntopicID := crypto.Keccak256Hash([]byte("unknownEvent"))
        unknownEvent, err := abi.EventByID(unknowntopicID)
        if err == nil {
            t.Errorf("EventByID should return an error if a topic is not found, test #%d", testnum)
        }
        if unknownEvent != nil {
            t.Errorf("We should not find any event for topic %s, test #%d", unknowntopicID.Hex(), testnum)
        }
    }
}

func TestDuplicateMethodNames(t *testing.T) {
    abiJSON := `[{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"}],"name":"transfer","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"},{"name":"data","type":"bytes"}],"name":"transfer","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"},{"name":"data","type":"bytes"},{"name":"customFallback","type":"string"}],"name":"transfer","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]`
    contractAbi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    if _, ok := contractAbi.Methods["transfer"]; !ok {
        t.Fatalf("Could not find original method")
    }
    if _, ok := contractAbi.Methods["transfer0"]; !ok {
        t.Fatalf("Could not find duplicate method")
    }
    if _, ok := contractAbi.Methods["transfer1"]; !ok {
        t.Fatalf("Could not find duplicate method")
    }
    if _, ok := contractAbi.Methods["transfer2"]; ok {
        t.Fatalf("Should not have found extra method")
    }
}

// TestDoubleDuplicateMethodNames checks that if transfer0 already exists, there won't be a name
// conflict and that the second transfer method will be renamed transfer1.
func TestDoubleDuplicateMethodNames(t *testing.T) {
    abiJSON := `[{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"}],"name":"transfer","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"},{"name":"data","type":"bytes"}],"name":"transfer0","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"value","type":"uint256"},{"name":"data","type":"bytes"},{"name":"customFallback","type":"string"}],"name":"transfer","outputs":[{"name":"ok","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]`
    contractAbi, err := JSON(strings.NewReader(abiJSON))
    if err != nil {
        t.Fatal(err)
    }
    if _, ok := contractAbi.Methods["transfer"]; !ok {
        t.Fatalf("Could not find original method")
    }
    if _, ok := contractAbi.Methods["transfer0"]; !ok {
        t.Fatalf("Could not find duplicate method")
    }
    if _, ok := contractAbi.Methods["transfer1"]; !ok {
        t.Fatalf("Could not find duplicate method")
    }
    if _, ok := contractAbi.Methods["transfer2"]; ok {
        t.Fatalf("Should not have found extra method")
    }
}

func (*ABI) EventByID Uses

func (abi *ABI) EventByID(topic common.Hash) (*Event, error)

EventByID looks an event up by its topic hash in the ABI and returns nil if none found.

func (*ABI) MethodById Uses

func (abi *ABI) MethodById(sigdata []byte) (*Method, error)

MethodById looks up a method by the 4-byte id returns nil if none found

func (ABI) Pack Uses

func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error)

Pack the given method name to conform the ABI. Method call's data will consist of method_id, args0, arg1, ... argN. Method id consists of 4 bytes and arguments are all 32 bytes. Method ids are created from the first 4 bytes of the hash of the methods string signature. (signature = baz(uint32,string32))

func (*ABI) UnmarshalJSON Uses

func (abi *ABI) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler interface

func (ABI) Unpack Uses

func (abi ABI) Unpack(v interface{}, name string, data []byte) (err error)

Unpack output in v according to the abi specification

func (ABI) UnpackIntoMap Uses

func (abi ABI) UnpackIntoMap(v map[string]interface{}, name string, data []byte) (err error)

UnpackIntoMap unpacks a log into the provided map[string]interface{}

type Argument Uses

type Argument struct {
    Name    string
    Type    Type
    Indexed bool // indexed is only used by events
}

Argument holds the name of the argument and the corresponding type. Types are used when packing and testing arguments.

func (*Argument) UnmarshalJSON Uses

func (argument *Argument) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler interface

type ArgumentMarshaling Uses

type ArgumentMarshaling struct {
    Name         string
    Type         string
    InternalType string
    Components   []ArgumentMarshaling
    Indexed      bool
}

type Arguments Uses

type Arguments []Argument

func (Arguments) LengthNonIndexed Uses

func (arguments Arguments) LengthNonIndexed() int

LengthNonIndexed returns the number of arguments when not counting 'indexed' ones. Only events can ever have 'indexed' arguments, it should always be false on arguments for method input/output

func (Arguments) NonIndexed Uses

func (arguments Arguments) NonIndexed() Arguments

NonIndexed returns the arguments with indexed arguments filtered out

func (Arguments) Pack Uses

func (arguments Arguments) Pack(args ...interface{}) ([]byte, error)

Pack performs the operation Go format -> Hexdata

func (Arguments) PackValues Uses

func (arguments Arguments) PackValues(args []interface{}) ([]byte, error)

PackValues performs the operation Go format -> Hexdata It is the semantic opposite of UnpackValues

func (Arguments) Unpack Uses

func (arguments Arguments) Unpack(v interface{}, data []byte) error

Unpack performs the operation hexdata -> Go format

func (Arguments) UnpackIntoMap Uses

func (arguments Arguments) UnpackIntoMap(v map[string]interface{}, data []byte) error

UnpackIntoMap performs the operation hexdata -> mapping of argument name to argument value

func (Arguments) UnpackValues Uses

func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error)

UnpackValues can be used to unpack ABI-encoded hexdata according to the ABI-specification, without supplying a struct to unpack into. Instead, this method returns a list containing the values. An atomic argument will be a list with one element.

type Event Uses

type Event struct {
    // Name is the event name used for internal representation. It's derived from
    // the raw name and a suffix will be added in the case of a event overload.
    //
    // e.g.
    // There are two events have same name:
    // * foo(int,int)
    // * foo(uint,uint)
    // The event name of the first one wll be resolved as foo while the second one
    // will be resolved as foo0.
    Name string
    // RawName is the raw event name parsed from ABI.
    RawName   string
    Anonymous bool
    Inputs    Arguments
}

Event is an event potentially triggered by the EVM's LOG mechanism. The Event holds type information (inputs) about the yielded output. Anonymous events don't get the signature canonical representation as the first LOG topic.

func (Event) ID Uses

func (e Event) ID() common.Hash

ID returns the canonical representation of the event's signature used by the abi definition to identify event names and types.

func (Event) Sig Uses

func (e Event) Sig() string

Sig returns the event string signature according to the ABI spec.

Example

event foo(uint32 a, int b) = "foo(uint32,int256)"

Please note that "int" is substitute for its canonical representation "int256"

func (Event) String Uses

func (e Event) String() string

type Method Uses

type Method struct {
    // Name is the method name used for internal representation. It's derived from
    // the raw name and a suffix will be added in the case of a function overload.
    //
    // e.g.
    // There are two functions have same name:
    // * foo(int,int)
    // * foo(uint,uint)
    // The method name of the first one will be resolved as foo while the second one
    // will be resolved as foo0.
    Name string
    // RawName is the raw method name parsed from ABI.
    RawName string
    Const   bool
    Inputs  Arguments
    Outputs Arguments
}

Method represents a callable given a `Name` and whether the method is a constant. If the method is `Const` no transaction needs to be created for this particular Method call. It can easily be simulated using a local VM. For example a `Balance()` method only needs to retrieve something from the storage and therefore requires no Tx to be send to the network. A method such as `Transact` does require a Tx and thus will be flagged `false`. Input specifies the required input parameters for this gives method.

func (Method) ID Uses

func (method Method) ID() []byte

ID returns the canonical representation of the method's signature used by the abi definition to identify method names and types.

func (Method) Sig Uses

func (method Method) Sig() string

Sig returns the methods string signature according to the ABI spec.

Example

function foo(uint32 a, int b) = "foo(uint32,int256)"

Please note that "int" is substitute for its canonical representation "int256"

func (Method) String Uses

func (method Method) String() string

type Type Uses

type Type struct {
    Elem *Type
    Kind reflect.Kind
    Type reflect.Type
    Size int
    T    byte // Our own type checking

    // Tuple relative fields
    TupleRawName  string   // Raw struct name defined in source code, may be empty.
    TupleElems    []*Type  // Type information of all tuple fields
    TupleRawNames []string // Raw field name of all tuple fields
    // contains filtered or unexported fields
}

Type is the reflection of the supported argument type

func NewType Uses

func NewType(t string, internalType string, components []ArgumentMarshaling) (typ Type, err error)

NewType creates a new reflection type of abi type given in t.

func (Type) String Uses

func (t Type) String() (out string)

String implements Stringer

Directories

PathSynopsis
bindPackage bind generates Ethereum contract Go bindings.
bind/backends

Package abi imports 14 packages (graph) and is imported by 740 packages. Updated 2020-04-01. Refresh now. Tools for package owners.