feat: contract definition load impl from RedStone Gateway

src/core/modules/impl/RedstoneGatewayContractDefinitionLoader.ts

@@ -0,0 +1,47 @@
+import { ContractDefinition, ContractDefinitionLoader, LoggerFactory, stripTrailingSlash, SwCache } from '@smartweave';
+import Arweave from 'arweave';
+import 'isomorphic-fetch';
+
+/**
+ * An extension to {@link ContractDefinitionLoader} that makes use of
+ * Redstone Gateway ({@link https://github.com/redstone-finance/redstone-sw-gateway})
+ * to load Contract Data.
+ *
+ * If the contract data is not available on RedStone Gateway - it fallbacks to default implementation
+ * in {@link ContractDefinitionLoader} - i.e. loads the definition from Arweave gateway.
+ */
+export class RedstoneGatewayContractDefinitionLoader extends ContractDefinitionLoader {
+  private readonly rLogger = LoggerFactory.INST.create('ContractDefinitionLoader');
+
+  constructor(
+    private readonly baseUrl: string,
+    arweave: Arweave,
+    cache?: SwCache<string, ContractDefinition<unknown>>
+  ) {
+    super(arweave, cache);
+    this.baseUrl = stripTrailingSlash(baseUrl);
+  }
+
+  async doLoad<State>(contractTxId: string, forcedSrcTxId?: string): Promise<ContractDefinition<State>> {
+    if (forcedSrcTxId) {
+      // no support for the evolve...
+      return await super.doLoad(contractTxId, forcedSrcTxId);
+    }
+
+    try {
+      return await fetch(`${this.baseUrl}/gateway/contracts/${contractTxId}`)
+        .then((res) => {
+          return res.ok ? res.json() : Promise.reject(res);
+        })
+        .catch((error) => {
+          if (error.body?.message) {
+            this.rLogger.error(error.body.message);
+          }
+          throw new Error(`Unable to retrieve contract data. Redstone gateway responded with status ${error.status}.`);
+        });
+    } catch (e) {
+      this.rLogger.debug('Falling back to default contracts loader');
+      return await super.doLoad(contractTxId, forcedSrcTxId);
+    }
+  }
+}