2b:null 2c:["$","title",null,{"children":"Dai.js Interactive | jpark | Observable"}] 31:T444,viewof testchainFound = { let prev; let i = 1; async function tryRpc() { try { const resp = await fetch(rpcUrl, { method: 'POST', headers: { Accept: 'application/json', 'Content-Type': 'application/json' }, body: JSON.stringify({ jsonrpc: '2.0', method: 'web3_clientVersion', params: [], id: i++ }) }); const respJson = await resp.json(); if (respJson.result.includes("TestRPC")) return [`✅ Testchain found at ${rpcUrl}`, true]; else return [`❌ Unable to find valid testchain at ${rpcUrl}`, false]; } catch (err) { return [ `❌ Unable to find testchain at ${rpcUrl}. **If you already have one running, consider restarting it**.`, false ]; } } while (true) { const [msg, testchainFound] = await tryRpc(); if (prev !== msg) { prev = msg; const _msg = md`${msg}`; _msg.value = testchainFound ? true : undefined; yield _msg; } await Promises.delay(2000); } }32:[{"id":"9f26a604f977c820a5e5e22f9bca44875903e3a1d2cfebfd0b0dbafb2d10dcb885eecb70829fea2fbf608ffc8b25f5b79cc6edca4849e0b2b1b9de459a0d55ca","href":"https://static.observableusercontent.com/files/9f26a604f977c820a5e5e22f9bca44875903e3a1d2cfebfd0b0dbafb2d10dcb885eecb70829fea2fbf608ffc8b25f5b79cc6edca4849e0b2b1b9de459a0d55ca","name":"buffer.js","type":"application/javascript","lastModified":1587945390206.176,"size":50900},{"id":"9be12ac725279ef7e7b384477950342da14647460fa33093c46d159691207005f5812cc7b902e7ffa1cfa4d7a24ec6a6dc77c41594a32aa62460be5c66dd4b6f","href":"https://static.observableusercontent.com/files/9be12ac725279ef7e7b384477950342da14647460fa33093c46d159691207005f5812cc7b902e7ffa1cfa4d7a24ec6a6dc77c41594a32aa62460be5c66dd4b6f","name":"oasis.gif","type":"image/gif","lastModified":1588021817198.875,"size":1595593}] 2f:{"id":"79e52bfcbe62a386","slug":"dai-js-interactive","title":"Dai.js Interactive","thumbnail":"4e9d022e58e2dea656d73e17076713254dc309d726556ebfccd3b7e21314dc99","access_level":"public","create_time":"$D2020-04-22T14:57:37.618Z","update_time":"$D2020-06-23T19:48:14.093Z","view_time":null,"first_public_time":"$D2020-05-05T06:00:45.133Z","fork":false,"stars":0,"starred":false,"owner":{"type":"team","id":"75a1153b1f93cd48","login":"jparklev","name":"jpark","avatar_url":"https://avatars-next.observableusercontent.com/9af5c11e007fc5f66f9624cbfc1bad0fd8296d28d64126149eb0992f07ac46b3","tier":"starter_2024"},"version":1767,"publish_version":1767,"role":null,"authored":false,"authors":[{"type":"individual","id":"50a8beb6caf2400d","login":"jparklev","name":"jpark","avatar_url":"https://avatars-next.observableusercontent.com/9af5c11e007fc5f66f9624cbfc1bad0fd8296d28d64126149eb0992f07ac46b3","tier":null}],"members":[{"type":"individual","id":"50a8beb6caf2400d","login":"jparklev","name":"jpark","avatar_url":"https://avatars-next.observableusercontent.com/9af5c11e007fc5f66f9624cbfc1bad0fd8296d28d64126149eb0992f07ac46b3","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":4,"collection":null,"type":"notebook","body":{"title":"Dai.js Interactive","cells":[{"id":0,"value":"md`# Dai.js Interactive`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":212,"value":"md`This is an interactive notebook with dai.js imported and configured to work with a local [MakerDAO testchain](https://github.com/makerdao/testchain). With it, you can explore dai.js in a sandboxed environment where all SCD and MCD contract have been deployed and properly configured. But, before going any further, make sure you have the latest testchain running. For our purposes, it should be as easy as\n\n~~~bash\n> git clone https://github.com/makerdao/testchain\n> git checkout eb26b045336019e04a1434415ee640cbe57e3bdf # IMPORTANT\n> npm install\n> scripts/launch -s default --fast\n~~~\n\nOnce you have it up, just make sure you see \"testchain found.\" Note that each cell of this notebook is a snippet of JavaScript. You can see (and edit!) the code for any cell by clicking the menu in the left margin. Feel free to experiment on this page, fork it, or [suggest changes](https://observablehq.com/@observablehq/suggestions-and-comments).\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":251,"value":"rpcUrl = \"http://127.0.0.1:2000\" // Ensure this matches your local RPC url","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":248,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":983,"value":"md`**Table of Contents**\n* [Instantiating the maker object](#instantiate)\n* [The testchain](#testchain)\n* [Accounts](#accounts)\n* [Transactions](#transactions)\n* [Oasis](#oasis)\n* [RPC Tracking](#rpcRequests)\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":990,"value":"instantiate = md`---\n## Instantiating the maker object\nAs the title of the notebook suggests, we're going to be using [dai.js](https://github.com/makerdao/dai.js) to interact with the Maker system. So, let's go ahead and instantiate it with the testchain URL. (see the [configuration section](https://docs.makerdao.com/dai.js/maker) of the docs for more on configuring dai.js)`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":24,"value":"maker = {\n testchainFound; // wait for the testchain\n return Maker.create('http', {\n plugins: [daiMcd.McdPlugin],\n provider: {\n url: rpcUrl,\n type: 'HTTP'\n }\n });\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1686,"value":"md`---`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":923,"value":"testchain = md`## The testchain\nThe MakerDAO testchain is a standard [Ganache](https://github.com/trufflesuite/ganache) chain with a few custom options passed in. Ganache makes for a nice testing ground as, in addition to implementing all the normal Ethereum RPC methods, it has a few handy additions.\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"{\n testchainFound;\n function mineBlock() {\n fetch(rpcUrl, {\n method: 'POST',\n body: JSON.stringify({\n jsonrpc: '2.0',\n method: 'evm_mine',\n id: 1000\n })\n });\n }\n return html`evm_mine, for example