1 files changed, 48 insertions, 0 deletions
diff --git a/test/utils/rpc.ts b/test/utils/rpc.ts
new file mode 100644
index 000000000..e331fa6d4
--- /dev/null
+++ b/test/utils/rpc.ts
@@ -0,0 +1,48 @@
+import * as ethUtil from 'ethereumjs-util';
+import * as request from 'request-promise-native';
+import {constants} from './constants';
+
+export class RPC {
+    private host: string;
+    private port: number;
+    private id: number;
+    constructor() {
+        this.host = constants.RPC_HOST;
+        this.port = constants.RPC_PORT;
+        this.id = 0;
+    }
+    public async takeSnapshotAsync(): Promise<number> {
+        const method = 'evm_snapshot';
+        const params: any[] = [];
+        const payload = this.toPayload(method, params);
+        const snapshotIdHex = await this.sendAsync(payload);
+        const snapshotId = ethUtil.bufferToInt(ethUtil.toBuffer(snapshotIdHex));
+        return snapshotId;
+    }
+    public async revertSnapshotAsync(snapshotId: number): Promise<boolean> {
+        const method = 'evm_revert';
+        const params = [snapshotId];
+        const payload = this.toPayload(method, params);
+        const didRevert = await this.sendAsync(payload);
+        return didRevert;
+    }
+    private toPayload(method: string, params: any[] = []): string {
+        const payload = JSON.stringify({
+            id: this.id,
+            method,
+            params,
+        });
+        this.id += 1;
+        return payload;
+    }
+    private async sendAsync(payload: string): Promise<any> {
+        const opts = {
+            method: 'POST',
+            uri: `http://${this.host}:${this.port}`,
+            body: payload,
+        };
+        const bodyString = await request(opts);
+        const body = JSON.parse(bodyString);
+        return body.result;
+    }
+}