Make speculative result backward compatible with Casper 1.5.x and Casper 2.0

Author: alexmyshchyshyn

src/rpc/response.ts

@@ -25,6 +25,7 @@ import {
   EntryPointValue,
   EraSummary,
   ExecutionInfo,
+  ExecutionResultV1,
   Hash,
   InitiatorAddr,
   MinimalBlockInfo,
@@ -831,14 +832,71 @@ export class SpeculativeExecResult {
   })
   blockHash?: Hash;
 
-  @jsonMember({
-    name: 'execution_result',
-    constructor: SpeculativeExecutionResult,
-    preserveNull: true
-  })
+  /**
+   * Execution result for Casper v2.0 (speculative execution format).
+   */
   executionResult?: SpeculativeExecutionResult;
 
+  /**
+   * Execution result for Casper v1.5.x (legacy execution format).
+   */
+  executionResultV1?: ExecutionResultV1;
+
+  /**
+   * Stores the raw json object if version could not be parsed.
+   */
   rawJSON?: any;
+
+  /**
+   * True if the parsed execution result matches Casper v1.5.x format.
+   */
+  get isV1(): boolean {
+    return !!this.executionResultV1;
+  }
+
+  /**
+   * True if the parsed execution result matches Casper v2.0 format.
+   */
+  get isV2(): boolean {
+    return !!this.executionResult;
+  }
+
+  /**
+   * Parses and returns a version-aware SpeculativeExecResult from raw JSON.
+   * Supports both Casper v1.5.x and v2.0 formats.
+   */
+  static fromJSON(json: any): SpeculativeExecResult {
+    const result = new SpeculativeExecResult();
+
+    result.apiVersion = json?.version;
+    const execJson = json?.result?.execution_result;
+    result.rawJSON = json;
+
+    result.blockHash = execJson?.block_hash
+      ? Hash.fromHex(execJson.block_hash)
+      : undefined;
+
+    if (
+      execJson &&
+      (execJson.block_hash ||
+        execJson.limit !== undefined ||
+        execJson.consumed !== undefined)
+    ) {
+      // Casper v2.0
+      result.executionResult = new TypedJSON(SpeculativeExecutionResult).parse(
+        execJson
+      );
+    } else if (execJson && ('Success' in execJson || 'Failure' in execJson)) {
+      // Casper v1.5.x
+      result.executionResultV1 = new TypedJSON(ExecutionResultV1).parse(
+        execJson
+      );
+    } else {
+      console.warn('Unknown execution_result format:', execJson);
+    }
+
+    return result;
+  }
 }
 
 @jsonObject

src/rpc/speculative_client.ts

@@ -9,7 +9,7 @@ import {
 import { RpcResponse, SpeculativeExecResult } from './response';
 import { IHandler } from './client';
 import { IDValue } from './id_value';
-import { Deploy, Hash, SpeculativeExecutionResult } from '../types';
+import { Deploy } from '../types';
 
 /**
  * A client for interacting with the speculative execution endpoint in the Casper Network.
@@ -85,16 +85,7 @@ export class SpeculativeClient {
         throw new Error(`Error parsing JSON`);
       }
 
-      const result = new SpeculativeExecResult();
-      result.apiVersion = data?.version;
-      result.executionResult = new TypedJSON(SpeculativeExecutionResult).parse(
-        data?.result?.execution_result
-      );
-      result.blockHash = data?.result?.execution_result?.block_hash
-        ? Hash.fromHex(data?.result?.execution_result?.block_hash)
-        : undefined;
-      result.rawJSON = data?.result;
-      return result;
+      return SpeculativeExecResult.fromJSON(data);
     } catch (error) {
       throw new Error(`Error parsing JSON, details: ${error}`);
     }