add sign api for state channel

src/api/index.ts

@@ -4,6 +4,7 @@ import { MessageApi } from './message';
 import { NetworkApi } from './network';
 import { ProviderApi } from './provider';
 import { SmartContractApi } from './smartContract';
+import { StateChannelApi } from './stateChannel';
 import { UtilsApi } from './utils';
 
 export * from './types';
@@ -22,4 +23,5 @@ export interface DApi {
   provider: ProviderApi;
   smartContract: SmartContractApi;
   utils: UtilsApi;
+  stateChannel: StateChannelApi;
 }

src/api/stateChannel.ts

@@ -0,0 +1,13 @@
+import { Response } from './types';
+
+export interface StateChannelApi {
+    sign({
+        channelId,
+        scriptHash,
+        message
+    }: {
+        channelId: string,
+        scriptHash: string,
+        message: string
+    }): Promise<Response>;
+}

src/client/stateChannel.ts

@@ -0,0 +1,9 @@
+import { StateChannelApi } from '../api/stateChannel';
+import { Response } from '../api/types';
+import { call } from './proxy';
+
+export const stateChannelApi: StateChannelApi = {
+    sign(args) {
+        return call<Response>('stateChannel.sign', args);
+    }
+};

src/provider.ts

@@ -83,4 +83,6 @@ export function registerProvider({ provider, logMessages }: { provider: DApi; lo
   checkedRegister('smartContract.deploy', provider.smartContract.deploy);
 
   checkedRegister('provider.getProvider', provider.provider.getProvider);
+
+  checkedRegister('stateChannel.sign', provider.stateChannel.sign);
 }