Featuring Asset Chain Testnet (#560)

docs/.vuepress/sidebar.ts

@@ -31,6 +31,10 @@ export const getSidebar = (locale: string) =>
                     text: "Arbitrum",
                     link: `${locale}/indexer/quickstart/quickstart_chains/arbitrum.md`,
                   },
+                  {
+                    text: "AssetChain Testnet",
+                    link: `${locale}/indexer/quickstart/quickstart_chains/asset-chain-testnet.md`,
+                  },
                   {
                     text: "Astar zkEVM",
                     link: `${locale}/indexer/quickstart/quickstart_chains/astar-zkevm.md`,

docs/indexer/quickstart/quickstart_chains/asset-chain-testnet.md

@@ -0,0 +1,187 @@
+# Asset Chain Testnet Quick Start
+
+The goal of this quick start guide is to index all transfers and approval events from the [Wrapped RWA](https://scan-testnet.assetchain.org/address/0x0FA7527F1050bb9F9736828B689c652AB2c483ef) on Asset Chain Testnet.
+
+<!-- @include: ../snippets/evm-quickstart-reference.md -->
+
+We use Ethereum packages, runtimes, and handlers (e.g. `@subql/node-ethereum`, `ethereum/Runtime`, and `ethereum/*Hander`) for Asset Chain. Since Asset Chain is an EVM-compatible layer-1, we can use the core Ethereum framework to index it.
+:::
+
+<!-- @include: ../snippets/evm-manifest-intro.md#level2 -->
+
+As we are indexing all transfers and approvals from the Wrapped ETH contract on Asset Chain's Network, the first step is to import the contract abi definition which can be obtained from from any standard [ERC-20 contract](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/). Copy the entire contract ABI and save it as a file called `erc20.abi.json` in the `/abis` directory.
+
+**Update the `datasources` section as follows:**
+
+```ts
+dataSources: [
+    {
+      kind: EthereumDatasourceKind.Runtime,
+      startBlock: 2330,
+      options: {
+        abi: "erc20",
+        // This is the contract address for Tether USD (USDT)
+        address: "0x0FA7527F1050bb9F9736828B689c652AB2c483ef",
+      },
+      assets: new Map([["erc20", { file: "./abis/erc20.abi.json" }]]),
+      mapping: {
+        file: "./dist/index.js",
+        handlers: [
+          {
+            kind: EthereumHandlerKind.Call, // We use ethereum handlers since Asset Chain Testnet is EVM-compatible
+            handler: "handleTransaction",
+            filter: {
+              /**
+               * The function can either be the function fragment or signature
+               * function: '0x095ea7b3'
+               * function: '0x7ff36ab500000000000000000000000000000000000000000000000000000000'
+               */
+              function: "approve(address spender, uint256 amount)",
+            },
+          },
+          {
+            kind: EthereumHandlerKind.Event,
+            handler: "handleLog",
+            filter: {
+              /**
+               * Follows standard log filters https://docs.ethers.io/v5/concepts/events/
+               * address: "0x60781C2586D68229fde47564546784ab3fACA982"
+               */
+              topics: [
+                "Transfer(address indexed from, address indexed to, uint256 amount)",
+              ],
+            },
+          },
+        ],
+      },
+    },
+  ],
+```
+
+The above code indicates that you will be running a `handleTransaction` mapping function whenever there is a `approve` method being called on any transaction from the WRWA contract.
+
+The code also indicates that you will be running a `handleLog` mapping function whenever there is a `Transfer` event being emitted from the [Wrapped RWA](https://scan-testnet.assetchain.org/address/0x0FA7527F1050bb9F9736828B689c652AB2c483ef).
+
+<!-- @include: ../snippets/ethereum-manifest-note.md -->
+
+<!-- @include: ../snippets/schema-intro.md#level2 -->
+
+Remove all existing entities and update the `schema.graphql` file as follows. Here you can see we are indexing block information such as the id, blockHeight, transfer receiver and transfer sender along with an approvals and all of the attributes related to them (such as owner and spender etc.).
+
+```graphql
+type Transfer @entity {
+  id: ID! # Transaction hash
+  blockHeight: BigInt
+  to: String!
+  from: String!
+  value: BigInt!
+  contractAddress: String!
+}
+
+type Approval @entity {
+  id: ID! # Transaction hash
+  blockHeight: BigInt
+  owner: String!
+  spender: String!
+  value: BigInt!
+  contractAddress: String!
+}
+```
+
+<!-- @include: ../snippets/note-on-entity-relationships.md -->
+
+<!-- @include: ../snippets/evm-codegen.md -->
+
+```ts
+import { Approval, Transfer } from "../types";
+import {
+  ApproveTransaction,
+  TransferLog,
+} from "../types/abi-interfaces/Erc20Abi";
+```
+
+<!-- @include: ../snippets/schema-note.md -->
+
+<!-- @include: ../snippets/mapping-intro.md#level2 -->
+
+Navigate to the default mapping function in the `src/mappings` directory. You will be able to see two exported functions `handleLog` and `handleTransaction`:
+
+```ts
+export async function handleLog(log: TransferLog): Promise<void> {
+  logger.info(`New transfer transaction log at block ${log.blockNumber}`);
+  assert(log.args, "No log.args");
+
+  const transaction = Transfer.create({
+    id: log.transactionHash,
+    blockHeight: BigInt(log.blockNumber),
+    to: log.args.to,
+    from: log.args.from,
+    value: log.args.value.toBigInt(),
+    contractAddress: log.address,
+  });
+
+  await transaction.save();
+}
+
+export async function handleTransaction(tx: ApproveTransaction): Promise<void> {
+  logger.info(`New Approval transaction at block ${tx.blockNumber}`);
+  assert(tx.args, "No tx.args");
+
+  const approval = Approval.create({
+    id: tx.hash,
+    owner: tx.from,
+    spender: await tx.args[0],
+    value: BigInt(await tx.args[1].toString()),
+    contractAddress: tx.to,
+  });
+
+  await approval.save();
+}
+```
+
+The `handleLog` function receives a `log` parameter of type `TransferLog` which includes log data in the payload. We extract this data and then save this to the store using the `.save()` function (_Note that SubQuery will automatically save this to the database_).
+
+The `handleTransaction` function receives a `tx` parameter of type `ApproveTransaction` which includes transaction data in the payload. We extract this data and then save this to the store using the `.save()` function (_Note that SubQuery will automatically save this to the database_).
+
+<!-- @include: ../snippets/ethereum-mapping-note.md -->
+
+<!-- @include: ../snippets/build.md -->
+
+<!-- @include: ../snippets/run-locally.md -->
+
+<!-- @include: ../snippets/query-intro.md -->
+
+```graphql
+# Write your query or mutation here
+{
+  query {
+    transfers(first: 5, orderBy: VALUE_DESC) {
+      totalCount
+      nodes {
+        id
+        blockHeight
+        from
+        to
+        value
+        contractAddress
+      }
+    }
+  }
+  approvals(first: 5, orderBy: BLOCK_HEIGHT_DESC) {
+    nodes {
+      id
+      blockHeight
+      owner
+      spender
+      value
+      contractAddress
+    }
+  }
+}
+```
+
+::: tip Note
+The final code of this project can be found [here](https://github.com/subquery/ethereum-subql-starter/tree/main/Asset%20Chain/asset-chain-testnet-starter).
+:::
+
+<!-- @include: ../snippets/whats-next.md -->