feat: fill in sequencer class methods

__tests__/defaultProvider.test.ts

@@ -86,6 +86,18 @@ describe('defaultProvider', () => {
       expect(classResponse).toHaveProperty('entry_points_by_type');
     });
 
+    // TODO see if feasible to split
+    describe('getClassHashAt & GetClass', () => {
+      test('responses', async () => {
+        const classHash = await testProvider.getClassHashAt(exampleContractAddress);
+        expect(typeof classHash).toBe('string');
+
+        const classResponse = await testProvider.getClass(classHash);
+        expect(classResponse).toHaveProperty('program');
+        expect(classResponse).toHaveProperty('entry_points_by_type');
+      });
+    });
+
     describe('getStorageAt', () => {
       test('with "key" type of number', () => {
         return expect(testProvider.getStorageAt(exampleContractAddress, 0)).resolves.not.toThrow();

src/provider/default.ts

@@ -61,6 +61,20 @@ export class Provider implements ProviderInterface {
     return this.provider.getClassAt(contractAddress, blockIdentifier);
   }
 
+  public async getClassHashAt(
+    contractAddress: string,
+    blockIdentifier: BlockIdentifier = 'pending'
+  ): Promise<string> {
+    // TODO flip params in one of the provider implementations?
+    if (this.provider instanceof RpcProvider)
+      return this.provider.getClassHashAt(blockIdentifier, contractAddress);
+    return this.provider.getClassHashAt(contractAddress, blockIdentifier);
+  }
+
+  public getClass(classHash: string): Promise<ContractClass> {
+    return this.provider.getClass(classHash);
+  }
+
   public async getEstimateFee(
     invocationWithTxType: Invocation,
     invocationDetails: InvocationsDetailsWithNonce,

src/provider/interface.ts

@@ -73,6 +73,26 @@ export abstract class ProviderInterface {
     blockIdentifier?: BlockIdentifier
   ): Promise<ContractClass>;
 
+  /**
+   * Returns the class hash deployed under the given address.
+   *
+   * @param contractAddress - contract address
+   * @param blockIdentifier - block identifier
+   * @returns Class hash
+   */
+  public abstract getClassHashAt(
+    contractAddress: string,
+    blockIdentifier?: BlockIdentifier
+  ): Promise<string>;
+
+  /**
+   * Returns the contract class deployed under the given class hash.
+   *
+   * @param classHash - class hash
+   * @returns Contract class of compiled contract
+   */
+  public abstract getClass(classHash: string): Promise<ContractClass>;
+
   /**
    * Gets the nonce of a contract with respect to a specific block
    *

src/provider/sequencer.ts

@@ -300,6 +300,17 @@ export class SequencerProvider implements ProviderInterface {
     );
   }
 
+  public async getClassHashAt(
+    contractAddress: string,
+    blockIdentifier: BlockIdentifier = 'pending'
+  ): Promise<string> {
+    return this.fetchEndpoint('get_class_hash_at', { blockIdentifier, contractAddress });
+  }
+
+  public async getClass(classHash: string): Promise<ContractClass> {
+    return this.fetchEndpoint('get_class_by_hash', { classHash }).then(parseContract);
+  }
+
   public async invokeFunction(
     functionInvocation: Invocation,
     details: InvocationsDetailsWithNonce