Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
スマートコントラクトプログラミング / Smart Contract Programming
Search
Kenji Saito
PRO
October 31, 2022
Technology
0
130
スマートコントラクトプログラミング / Smart Contract Programming
2022年10月31日(月)、慶應義塾大学大学院メディアデザイン研究科「サービスデザインプロジェクト B」2022秋で使用したスライドです。
Kenji Saito
PRO
October 31, 2022
Tweet
Share
More Decks by Kenji Saito
See All by Kenji Saito
マニフェスト: 人類の知のフロンティアに向けた拡張的足場へ / Manifesto: Toward Expansive Scaffolding for Humanity's Knowledge Frontier
ks91
PRO
0
8
続・スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance, Continued
ks91
PRO
0
42
スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance
ks91
PRO
0
63
シン・ブロックチェーン / Truth of Blockchain
ks91
PRO
0
92
パスワード/パスフレーズと認証 / Password, Passphrase and Authentication
ks91
PRO
0
37
git と GitHub / git and GitHub
ks91
PRO
0
35
ソフトウェアの開発と保守 / Software Development and Maintenance
ks91
PRO
0
50
インターネットの特徴 / Features of the Internet
ks91
PRO
0
34
インターネットのガバナンス / Governance of the Internet
ks91
PRO
0
30
Other Decks in Technology
See All in Technology
怖くない!はじめてのClaude Code
shinya337
0
400
赤煉瓦倉庫勉強会「Databricksを選んだ理由と、絶賛真っ只中のデータ基盤移行体験記」
ivry_presentationmaterials
2
360
ビギナーであり続ける/beginning
ikuodanaka
3
760
KubeCon + CloudNativeCon Japan 2025 Recap by CA
ponkio_o
PRO
0
300
Operating Operator
shhnjk
1
590
OPENLOGI Company Profile
hr01
0
67k
freeeのアクセシビリティの現在地 / freee's Current Position on Accessibility
ymrl
2
190
Core Audio tapを使ったリアルタイム音声処理のお話
yuta0306
0
190
Should Our Project Join the CNCF? (Japanese Recap)
whywaita
PRO
0
340
ビズリーチにおけるリアーキテクティング実践事例 / JJUG CCC 2025 Spring
visional_engineering_and_design
1
120
さくらのIaaS基盤のモニタリングとOpenTelemetry/OSC Hokkaido 2025
fujiwara3
3
440
MobileActOsaka_250704.pdf
akaitadaaki
0
120
Featured
See All Featured
Making the Leap to Tech Lead
cromwellryan
134
9.4k
Why You Should Never Use an ORM
jnunemaker
PRO
58
9.4k
KATA
mclloyd
30
14k
Automating Front-end Workflow
addyosmani
1370
200k
A designer walks into a library…
pauljervisheath
207
24k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
50
5.5k
The Art of Delivering Value - GDevCon NA Keynote
reverentgeek
15
1.5k
RailsConf 2023
tenderlove
30
1.1k
The Cult of Friendly URLs
andyhume
79
6.5k
A Tale of Four Properties
chriscoyier
160
23k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
34
3.1k
It's Worth the Effort
3n
185
28k
Transcript
Service Design, generated by Stable Diffusion B 2022 3 (
) B 2022 — 3 — 2022-10-31 – p.1/93
https://speakerdeck.com/ks91 ( ) ( ) Discord Discord ( / /
) Zoom URL ( ) B 2022 — 3 — 2022-10-31 – p.2/93
( ) 1 10 17 • 2 10 24 •
3 10 31 • 4 11 7 5 11 14 1 6 11 21 2 7 11 28 8 12 5 Discord B 2022 — 3 — 2022-10-31 – p.3/93
– : : Ethereum ( ) Ethereum (1)(2)(3) ( ←
) B 2022 — 3 — 2022-10-31 – p.4/93
– B 2022 — 3 — 2022-10-31 – p.5/93
ެ։ா ެ։Ͱͳ͚ΕͳΒͳ͍ ʜ ຊਓ ɾૹۚه ɾίʔυ ɾσʔλͷมԽ ɾ࣮ߦϩά ݕӾͰ͖Δୈࡾऀ ͜Εɺ
ه͍ͨ͠Μ͚ͩͲ ͋ͳͨ ॻ͍ͨΒμϝ ͜ͷ༰ ॻ͍ͨΒμϝ ॻ͍ͪΌͬͨͷʁ ͜͏ॻ͖͑·͠ΐ͏ ॻ͍ͯͳ͍ͷʁ ͜͏ॻ͔Εͨ͜ͱʹ ͠·͠ΐ͏ ॻ͍ͪΌͬͨͷʁ ফ͠·͠ΐ͏ %P4 ߈ܸͱ͔Ͱ ͯ͠ࢭΊ·͠ΐ͏ B 2022 — 3 — 2022-10-31 – p.6/93
( ) ( ) ( ) ↓ ( ( ))
(BP : Blockchain Property ) BP-1 : ( ) BP-2 : ( ( ) ) BP-3 : ( ) ( ) ( ) B 2022 — 3 — 2022-10-31 – p.7/93
( ) (LIFO : Last In, First Out) ( )
B 2022 — 3 — 2022-10-31 – p.8/93
( ) ( ) ( ) ( ) ( 16
) SHA (Secure Hash Algorithm) ( ) 1bit B 2022 — 3 — 2022-10-31 – p.9/93
( ) ( ) < , > ( ) ←
: < , > : : < , , > : OK ( 1 ) NG ( ) B 2022 — 3 — 2022-10-31 – p.10/93
BP-1 ( ), BP-2 ( ) BBc-1 f : →
BP-3 ( ) ( ) ( ) ← BP-2 ← BP-3 ( ) (BP-2 ) ( ) ← BP-3 (?) + ← BP-{1,2} B 2022 — 3 — 2022-10-31 – p.11/93
[Lamport 1984][Schneider 1990] (1) (2) (3) (4) ( ) ←
↑ B 2022 — 3 — 2022-10-31 – p.12/93
TX : transaction ( 4 TX ) SMRP (State Machine
Replication Problem) SMRP-1 ( ) SMRP-2 : B 2022 — 3 — 2022-10-31 – p.13/93
( ) ( ) ϒϩοΫ൪߸O ϒϩοΫ൪߸O ϒϩοΫ൪߸O ϒϩοΫ൪߸O
ϒϩοΫ൪߸O ϒϩοΫ൪߸O ϒϩοΫ൪߸O ϒϩοΫ൪߸O ͍ͪΜهɾॻ͖͑ͷίετ͕ߴ͍ྺ࢙ ࠷վ͟Μ͠ʹ͍͘ྺ࢙ ͕༗ޮ ͻͱͭखલͷϒϩοΫͷ ʮμΠδΣετʯ σδλϧॺ໊͞Εͨ ʮτϥϯβΫγϣϯ औҾ ʯ ϒϩοΫΛ࡞ΔͨΊʹɺͦͷʮμΠδΣετʯ͕͋ΔҎԼͱ͍͏݅Λຬͨͨ͠Γ 1SPPGPG8PSL Ծ௨՟ͷ࣋ͪʹԠͨ͡ݖརΛͬͨථͰউͬͨΓ 1SPPGPG4UBLF ͢Δඞཁ͕͋Δ ίετ͕͔͔Δ ϒϩοΫΛ࡞ΔਓͦͷதʹࣗʹѼͯͨ Ծ௨՟ͰͷใुΛॻ͖ࠐΉ͜ͱ͕Ͱ͖ɺ ͦͷϒϩοΫ͕༗ޮͳྺ࢙ͷதʹ͋Δ߹ʹ ݶΓใु༗ޮͱͳΔ τϥϯβΫγϣϯͷଘࡏΛ֬ೝ͢Δ ͨΊͷޮతͳํ๏͕ఏڙ͞ΕΔ ਖ਼ੑ ଘࡏੑ །Ұੑ Proof of Work ( ) . . . → B 2022 — 3 — 2022-10-31 – p.14/93
(BP-3 ) ( : ) (BP-3 ) ( : )
← NFT BP-{1,2,3} BP-{1, 2} ⇒ B 2022 — 3 — 2022-10-31 – p.15/93
(Confidentiality) BP-{1,2,3} ↑ ( = ) (Integrity) BP-3 (Availability) BP-2
B 2022 — 3 — 2022-10-31 – p.16/93
2009 ↑ 13 ( 5 ) B 2022 — 3
— 2022-10-31 – p.17/93
( ) ADR (Active (space) Debris Removal) : https://doi.org/10.1109/TCSS.2018.2890655 (1930
) ( ) B 2022 — 3 — 2022-10-31 – p.18/93
( ) ( ) ( ) B 2022 — 3
— 2022-10-31 – p.19/93
( ) ( - ) : https://doi.org/10.1016/j.future.2019.05.019 B 2022 —
3 — 2022-10-31 – p.20/93
( ) ( ) ( ) B 2022 — 3
— 2022-10-31 – p.21/93
( ) B 2022 — 3 — 2022-10-31 – p.22/93
/ ( ) ( ) ( ) ( ) B
2022 — 3 — 2022-10-31 – p.23/93
( ) ( ) ( ) B 2022 — 3
— 2022-10-31 – p.24/93
( ) : https://www.lij.jp/html/jli/jli_2017/ 2017summer_p018.pdf B 2022 — 3 —
2022-10-31 – p.25/93
( ) ( ) B 2022 — 3 — 2022-10-31
– p.26/93
B 2022 — 3 — 2022-10-31 – p.27/93
with ( ) ( ) : https://doi.org/10.1016/j.icte.2021.08.012 ( ) B
2022 — 3 — 2022-10-31 – p.28/93
DNS : https://ieeexplore.ieee.org/document/9686409 ( ) IP AS B 2022 —
3 — 2022-10-31 – p.29/93
( ) ( ) : https://ieeexplore.ieee.org/document/9686409 ( ) : https://doi.org/10.1016/j.icte.2021.08.012
(web ) B 2022 — 3 — 2022-10-31 – p.30/93
( ) ( ) ( ) : https://doi.org/10.1016/j.icte.2021.08.012 ( )
( ) ( ) : https://ieeexplore.ieee.org/document/9686409 B 2022 — 3 — 2022-10-31 – p.31/93
( ) ( ) : https://ieeexplore.ieee.org/document/9686409 3D : https://arxiv.org/abs/2203.03119 (
) : HACCP ( ) B 2022 — 3 — 2022-10-31 – p.32/93
— τʔΫϯ ସ՟ฎ εϚʔτίϯτϥΫτ ݕূՄೳͳঢ়ଶϚγϯ ϓϩϏφϯε དྷྺূ໌ ସՄೳ ঈؐෆೳ
ସՄೳ ঈؐՄೳ ସෆೳ ঈؐՄೳ ସෆೳ ঈؐෆೳ ূ໌͢Δ ಉఆ͢Δ ࢧ͍ ࠷ॳͷԠ༻ *%Χʔυ ηΩϡϦςΟ τʔΫϯ ূ݊ ηϯαʔ ྲྀɾ Ҩݴॻ อݥਃ ͢Δ ײ͢Δ தԝۜߦ σδλϧ௨՟ ҭήʔϜ ൿີ伴Λ͑Δ͔Βຊਓʁ ෛ࠴ Ξηοτͷ දݱΛҠసͰ͖Δʁ ొ͞Εͨίʔυͱ ͦͷ࣮ߦϩάͱ݁Ռͷ ਅਖ਼ੑΛ୲อͰ͖Δʁ ݖҖ͕ Կ͔ͷ༰Λূ໌͢Δʁ ࣋ଓ͢Δଘࡏʹ͍ͭͯ هΛΞοϓσʔτՄʁ ओମ͕͍ͳ͘ͳͬͯ աڈͷσʔλ༗ޮʁ /'5 Ұൠతͳ ೝࣝ ػೳͷ ੳ݁Ռ B 2022 — 3 — 2022-10-31 – p.33/93
Ethereum macOS (Monterey 12.6) + Homebrew Linux (Ubuntu 22.04) (x86/AMD64
and ARM) Windows 10/11 + Windows Subsystem for Linux (Ubuntu ) Ethereum solidity brownie B 2022 — 3 — 2022-10-31 – p.34/93
Solidity Ethereum ( ) http://solidity.readthedocs.io/en/latest/installing-solidity.html Linux (on Windows) “sudo apt”,
macOS “brew” Linux ARM git clone dependencies solc 0.8.16 (9/6 ) $ solc --version brownie py-solc-x solc (dependencies) ( solc py-solc-x ) B 2022 — 3 — 2022-10-31 – p.35/93
Ganache Ethereum RPC npm ( ) macOS https://qiita.com/kyosuke5_20/items/c5f68fc9d89b84c0df09 Linux https://qiita.com/seibe/items/36cef7df85fe2cefa3ea
npm Ganache $ sudo npm install -g ganache B 2022 — 3 — 2022-10-31 – p.36/93
Python3 macOS $ brew install python3 Python 3.8 Homebrew $
brew uninstall --ignore-dependencies
[email protected]
$ brew install
[email protected]
/usr/local/opt/
[email protected]
/bin/python3 Linux $ sudo apt update $ sudo apt install python3.8 python3.8-dev python3.8-venv python3.8-tk 16.10 python3(.8) apt (PPA ) python3 python3-dev python3-venv python3-tk B 2022 — 3 — 2022-10-31 – p.37/93
macOS : . . . macOS wget brew dyld: Library
not loaded: /usr/local/opt/gettext/lib/libintl.8.dylib $ brew uninstall --force gettext $ brew install gettext B 2022 — 3 — 2022-10-31 – p.38/93
Python (venv) macOS (Linux python3 ) ‘python3.8’ ‘python3’ $ python3.8
-m venv bbc1env $ source bbc1env/bin/activate (bbc1env) $ pip install -U pip (bbc1env) $ pip install wheel bbc1env ( BBc-1 ) ( ) (bbc1env) $ deactivate B 2022 — 3 — 2022-10-31 – p.39/93
Brownie Python Ethereum https://eth-brownie.readthedocs.io Brownie $ pip install eth-brownie version
1.19.1 (9/6 ) B 2022 — 3 — 2022-10-31 – p.40/93
$ brownie init ( ERC-20 ) $ brownie bake token
$ cd token B 2022 — 3 — 2022-10-31 – p.41/93
contracts (macOS Linux (x86/AMD64) ) $ brownie compile Linux (ARM)
(AMD64 ) $ python # >>> import solcx >>> solcx.compile_solc(’0.6.12’) # >>> quit() /tmp ∼/.solcx/solc-v0.6.12 ( ) $ pytest tests B 2022 — 3 — 2022-10-31 – p.42/93
Brownie $ brownie console Python >>> len(accounts) 10 >>> accounts[0].balance()
100000000000000000000 >>> quit() B 2022 — 3 — 2022-10-31 – p.43/93
Ethereum Görli B 2022 — 3 — 2022-10-31 – p.44/93
infura.io Brownie https://infura.io SIGN UP PROJECT ID infura Ethereum API
infura . . . infura.io PROJECT ID WEB3_INFURA_PROJECT_ID PROJECT ID (∼/.bash_profile ) $ export WEB3_INFURA_PROJECT_ID= PROJECT ID B 2022 — 3 — 2022-10-31 – p.45/93
G¨ orli ETH brownie console Görli >>> network.disconnect() >>> network.connect(’goerli’)
>>> len(accounts) 0 >>> accounts.add() <LocalAccount object ’ 16 ’> >>> accounts[0].private_key 16 >>> quit() Görli Testnet ETH Faucet ETH https://goerlifaucet.com ( ) ( ) https://metamask.io/ B 2022 — 3 — 2022-10-31 – p.46/93
G¨ orli ETH brownie console Görli ETH >>> network.disconnect() >>>
network.connect(’goerli’) >>> len(accounts) 0 >>> accounts.add( 16 ) <LocalAccount object ’ 16 ’> >>> accounts[0].balace() ETH >>> quit() ETH >>> accounts[0].transfer(accounts[1], "0.01 ether") B 2022 — 3 — 2022-10-31 – p.47/93
Ethereum B 2022 — 3 — 2022-10-31 – p.48/93
Ethereum Vitalik Buterin, “Ethereum White Paper: A NEXT GENERATION SMART
CONTRACT & DECENTRALIZED APPLICATION PLATFORM” 12 (= ) = ⇒ → Dapps ( / / ) B 2022 — 3 — 2022-10-31 – p.49/93
( ) B 2022 — 3 — 2022-10-31 – p.50/93
. . . B 2022 — 3 — 2022-10-31 –
p.51/93
vs. B 2022 — 3 — 2022-10-31 – p.52/93
= run B 2022 — 3 — 2022-10-31 – p.53/93
Ether Ethereum EOA : Externally-Owned Account ( ) Ether EVM
EVM B 2022 — 3 — 2022-10-31 – p.54/93
EVM : Ethereum Virtual Machine Gas ( EVM = (
burn)) . . . B 2022 — 3 — 2022-10-31 – p.55/93
EVM : : ← : Solidity — JavaScript LLL —
Lisp Vyper — Python Fe — Vyper Rust ← NEW! Solidity Vyper Python B 2022 — 3 — 2022-10-31 – p.56/93
Solidity ( ) pragma solidityˆ0.7.0; contract IndivisibleAsset { /* */
string public _name; string public _symbol; uint256 public _quantity; address public _owner; constructor(string memory name, string memory symbol, uint256 quantity) public { _name = name; _symbol = symbol; _quantity = quantity; _owner = msg.sender; } function transfer(address to) public returns (bool) { require (_owner == msg.sender); _owner = to; return true; } } B 2022 — 3 — 2022-10-31 – p.57/93
( , ) (constructor) (deploy) = ( ) ( )
ETH Trusted Actor Model B 2022 — 3 — 2022-10-31 – p.58/93
Ethereum B 2022 — 3 — 2022-10-31 – p.59/93
(1) : ERC20 $ brownie bake token B 2022 —
3 — 2022-10-31 – p.60/93
Solidity JavaScript ( , ) (constructor) ( ) ( )
Ether Ethereum B 2022 — 3 — 2022-10-31 – p.61/93
pragma solidity ˆ0.6.0; /* 0.8.x */ contract Token { (
) : (EVM ) : constructor (...) public { /* */ : } function balanceOf(...) { /* ( ) */ : } : } constructor C (/* */ // ) B 2022 — 3 — 2022-10-31 – p.62/93
ERC20 ERC (Ethereum Request for Comment) 20 https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md contract ERC20
{ function totalSupply() constant returns (uint totalSupply); function balanceOf(address _owner) constant returns (uint balance); function transfer(address _to, uint _value) returns (bool success); function transferFrom(address _from, address _to, uint _value) returns (bool success); function approve(address _spender, uint _value) returns (bool success); function allowance(address _owner, address _spender) constant returns (uint remaining); event Transfer(address indexed _from, address indexed _to, uint _value); event Approval(address indexed _owner, address indexed _spender, uint _value); } name/ , symbol/ , decimals/ approve allowance ERC-777 ( ) B 2022 — 3 — 2022-10-31 – p.63/93
ERC20 ERC20 ( ) ⇒ ERC20 ( ERC20 ) ERC20
⇒ B 2022 — 3 — 2022-10-31 – p.64/93
(fungible) ERC-20 → ERC-223 (draft) or ERC-777 ( )( )
(non-fungible) ERC-721 ( ) ERC-1155 ( ) ERC-3525 (SLOT ) B 2022 — 3 — 2022-10-31 – p.65/93
Token ( ) string public symbol; string public name; uint256
public decimals; uint256 public totalSupply; mapping(address => uint256) balances; . . . name, symbol decimals : 2 100 1.00 mapping balances B 2022 — 3 — 2022-10-31 – p.66/93
Token ( ) event Transfer(address from, address to, uint256 value);
Token function emit Transfer() ( ) B 2022 — 3 — 2022-10-31 – p.67/93
Token ( ) constructor( string memory _symbol, string memory _name,
uint256 _decimals, uint256 _totalSupply ) public { symbol = _symbol; name = _name; decimals = _decimals; totalSupply = _totalSupply; balances[msg.sender] = _totalSupply; } msg.sender _totalSupply B 2022 — 3 — 2022-10-31 – p.68/93
Token balanceOf() function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner]; } B 2022 — 3 — 2022-10-31 – p.69/93
Token transfer() function transfer(address _to, uint256 _value) public returns (bool)
{ balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } ( ↑ ) OpenZeppelin https://openzeppelin.org B 2022 — 3 — 2022-10-31 – p.70/93
(2) : B 2022 — 3 — 2022-10-31 – p.71/93
GitHub git clone $ git clone https://github.com/ks91/sample-smart-contracts.git sample-smart-contracts contracts, scripts
tests token Token Solidity 0.5 0.6/0.7 (Token ) Solidity B 2022 — 3 — 2022-10-31 – p.72/93
(m2 ) 1 1 B 2022 — 3 — 2022-10-31
– p.73/93
IndivisibleAsset string public _name_; string public _symbol_; uint256 public _quantity_;
address public _owner_; _name_ ( ) _symbol_ _quantity_ (m2 ) _owner_ ‘_’ Solidity . . . B 2022 — 3 — 2022-10-31 – p.74/93
IndivisibleAsset event Transfer(address indexed from, address indexed to); from to
indexed B 2022 — 3 — 2022-10-31 – p.75/93
IndivisibleAsset constructor (string name, string symbol, uint256 quantity) public {
_name_ = name; _symbol_ = symbol; _quantity_ = quantity; _owner_ = msg.sender; } B 2022 — 3 — 2022-10-31 – p.76/93
IndivisibleAsset getOwner() function getOwner() public view returns (address) { return
(_owner_); } B 2022 — 3 — 2022-10-31 – p.77/93
IndivisibleAsset transfer() function transfer(address to) public returns (bool) { require(_owner_
== msg.sender); _owner_ = to; emit Transfer(msg.sender, to); return true; } require (function ) ( ) $ brownie compile B 2022 — 3 — 2022-10-31 – p.78/93
scripts/indivisible asset.py from brownie import * def main(): accounts[0].deploy(IndivisibleAsset, "5322
Endo, Fujisawa", "mˆ2", 300) SFC (300m2 ) ( ) B 2022 — 3 — 2022-10-31 – p.79/93
from brownie import * import pytest def test_owner_and_transfer(IndivisibleAsset): asset =
accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) assert asset.getOwner() == accounts[0] asset.transfer(accounts[1], {’from’: accounts[0]}) assert asset.getOwner() == accounts[1] try: asset.transfer(accounts[0], {’from’: accounts[0]}) done = 1 except: done = 0 assert done == 0 accounts[0] accounts[1] B 2022 — 3 — 2022-10-31 – p.80/93
$ pytest tests/test_indivisible_asset.py B 2022 — 3 — 2022-10-31 –
p.81/93
(3) : B 2022 — 3 — 2022-10-31 – p.82/93
transfer settle, retrieve asset, retrieve token 3 B 2022 —
3 — 2022-10-31 – p.83/93
1. ( ) 2. ( ) 3. ( ) B
2022 — 3 — 2022-10-31 – p.84/93
OneTimeEscrow settle() function settle() public returns (bool) { require(_token_.balanceOf(address(this)) >=
_price_); /* this */ require(_asset_.getOwner() == address(this)); _token_.transfer(_seller_ , _price_); _asset_.transfer(_buyer_); emit Settled(); /* */ return true; } settle() transfer ( / ) $ brownie compile B 2022 — 3 — 2022-10-31 – p.85/93
(1) from brownie import * import pytest def test_deploy_and_settle(Token, IndivisibleAsset,
OneTimeEscrow): asset = accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) token = accounts[0].deploy(Token, "Test Token", "TEST", 18, "1000 ether") B 2022 — 3 — 2022-10-31 – p.86/93
(2) token.transfer(accounts[1], 300, {’from’: accounts[0]}) escrow = accounts[0].deploy(OneTimeEscrow, token, accounts[1],
asset, accounts[0], 300) accounts[0] accounts[1] 300 300 TX accounts[1] accounts[0] 300 bake Token 300 ETH wei B 2022 — 3 — 2022-10-31 – p.87/93
(3) token.transfer(escrow, 300, {’from’: accounts[1]}) asset.transfer(escrow, {’from’: accounts[0]}) assert token.balanceOf(accounts[0])
== 999999999999999999700 assert token.balanceOf(accounts[1]) == 0 assert token.balanceOf(escrow) == 300 assert asset.getOwner() == escrow accounts[1] ( ) 300 accounts[0] ( ) B 2022 — 3 — 2022-10-31 – p.88/93
(4) escrow.settle({’from’: accounts[0]}) assert token.balanceOf(accounts[0]) == 1000000000000000000000 assert token.balanceOf(accounts[1]) ==
0 assert token.balanceOf(escrow) == 0 assert asset.getOwner() == accounts[1] settle() accounts[0] OK B 2022 — 3 — 2022-10-31 – p.89/93
$ pytest tests/test_one_time_escrow.py : settle() ⇒ Discord B 2022 —
3 — 2022-10-31 – p.90/93
B 2022 — 3 — 2022-10-31 – p.91/93
1. (1) (2) Ethereum 2022 11 5 ( ) 23:59
JST B 2022 — 3 — 2022-10-31 – p.92/93
B 2022 — 3 — 2022-10-31 – p.93/93