feat: impl rns.resolver(name) - getter function

src/index.ts

@@ -135,6 +135,20 @@ export default class extends Composer implements RNS {
     return this._resolutions.setContenthash(domain, content, options);
   }
 
+  /**
+   * Get decoded contenthash of a given domain.
+   *
+   * @throws DOMAIN_NOT_EXISTS if the given domain does not exists - KB012
+   * @throws NO_RESOLVER when the domain doesn't have resolver - KB003
+   *
+   * @param domain - Domain to be resolved
+   *
+   * @returns Address of the resolver associated with the given domain
+   */
+  resolver(domain: string): Promise<string> {
+    return this._resolutions.resolver(domain);
+  }
+
   /**
    * Set resolver of a given domain.
    *

src/resolutions.ts

@@ -301,6 +301,25 @@ export default class extends Composer implements Resolutions {
     return this.estimateGasAndSendTransaction(contractMethod, options);
   }
 
+  async resolver(domain: string): Promise<string> {
+    await this.compose();
+    const node: string = namehash(domain);
+
+    const domainOwner = await
+    this._contracts.registry.methods.owner(node).call();
+    if (domainOwner === ZERO_ADDRESS) {
+      this._throw(DOMAIN_NOT_EXISTS);
+    }
+
+    const resolverAddress: string = await
+    this._contracts.registry.methods.resolver(node).call();
+    if (resolverAddress === ZERO_ADDRESS) {
+      this._throw(NO_RESOLVER);
+    }
+
+    return resolverAddress;
+  }
+
   async setResolver(
     domain: string, resolver: string, options?: TransactionOptions,
   ): Promise<string> {

src/types/resolutions.ts

@@ -65,6 +65,13 @@ export interface Resolutions {
    */
   setContenthash(domain: string, content: string, options?: TransactionOptions): any;
 
+  /**
+   * Get resolver of a given domain.
+   *
+   * @param domain - Domain to be resolved
+   */
+  resolver(domain: string): Promise<string>;
+
   /**
    * Set resolver of a given domain.
    *