Add api.connection.getReserveBase() (#1259)

* Returns the current minimum reserve, in drops of XRP, that is required
for an account.

* Release 1.6.6-beta.2

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ripple-lib",
-  "version": "1.6.6-beta.1",
+  "version": "1.6.6-beta.2",
   "license": "ISC",
   "description": "A TypeScript/JavaScript API for interacting with the XRP Ledger in Node.js and the browser",
   "files": [

src/common/connection.ts

@@ -38,6 +38,23 @@ export interface ConnectionOptions {
  */
 export type ConnectionUserOptions = Partial<ConnectionOptions>
 
+/**
+ * Ledger Stream Message
+ * https://xrpl.org/subscribe.html#ledger-stream
+ */
+interface LedgerStreamMessage {
+  type?: 'ledgerClosed' // not present in initial `subscribe` response
+  fee_base: number
+  fee_ref: number
+  ledger_hash: string
+  ledger_index: number
+  ledger_time: number
+  reserve_base: number
+  reserve_inc: number
+  txn_count?: number // not present in initial `subscribe` response
+  validated_ledgers?: string
+}
+
 /**
  * Represents an intentionally triggered web-socket disconnect code.
  * WebSocket spec allows 4xxx codes for app/library specific codes.
@@ -118,10 +135,11 @@ function websocketSendAsync(ws: WebSocket, message: string) {
  * captured by the Connection class over time.
  */
 class LedgerHistory {
-  private availableVersions = new RangeSet()
-  latestVersion: null | number = null
   feeBase: null | number = null
   feeRef: null | number = null
+  latestVersion: null | number = null
+  reserveBase: null | number = null
+  private availableVersions = new RangeSet()
 
   /**
    * Returns true if the given version exists.
@@ -143,25 +161,22 @@ class LedgerHistory {
    * of whether ledger history data exists or not. If relevant ledger data
    * is found, we'll update our history (ex: from a "ledgerClosed" event).
    */
-  update(responseData: {
-    ledger_index?: string
-    validated_ledgers?: string
-    fee_base?: string
-    fee_ref?: string
-  }) {
-    this.latestVersion = Number(responseData.ledger_index)
-    if (responseData.validated_ledgers) {
+  update(ledgerMessage: LedgerStreamMessage) {
+    // type: ignored
+    this.feeBase = ledgerMessage.fee_base
+    this.feeRef = ledgerMessage.fee_ref
+    // ledger_hash: ignored
+    this.latestVersion = ledgerMessage.ledger_index
+    // ledger_time: ignored
+    this.reserveBase = ledgerMessage.reserve_base
+    // reserve_inc: ignored (may be useful for advanced use cases)
+    // txn_count: ignored
+    if (ledgerMessage.validated_ledgers) {
       this.availableVersions.reset()
-      this.availableVersions.parseAndAddRanges(responseData.validated_ledgers)
+      this.availableVersions.parseAndAddRanges(ledgerMessage.validated_ledgers)
     } else {
       this.availableVersions.addValue(this.latestVersion)
     }
-    if (responseData.fee_base) {
-      this.feeBase = Number(responseData.fee_base)
-    }
-    if (responseData.fee_ref) {
-      this.feeRef = Number(responseData.fee_ref)
-    }
   }
 }
 
@@ -563,11 +578,6 @@ export class Connection extends EventEmitter {
     await this.connect()
   }
 
-  async getLedgerVersion(): Promise<number> {
-    await this._waitForReady()
-    return this._ledger.latestVersion!
-  }
-
   async getFeeBase(): Promise<number> {
     await this._waitForReady()
     return this._ledger.feeBase!
@@ -578,6 +588,16 @@ export class Connection extends EventEmitter {
     return this._ledger.feeRef!
   }
 
+  async getLedgerVersion(): Promise<number> {
+    await this._waitForReady()
+    return this._ledger.latestVersion!
+  }
+
+  async getReserveBase(): Promise<number> {
+    await this._waitForReady()
+    return this._ledger.reserveBase!
+  }
+
   /**
    * Returns true if the given range of ledger versions exist in history
    * (inclusive).

test/connection-test.ts

@@ -98,6 +98,7 @@ describe('Connection', function() {
     )
     assert.strictEqual(await this.api.connection.getFeeBase(), 10)
     assert.strictEqual(await this.api.connection.getFeeRef(), 10)
+    assert.strictEqual(await this.api.connection.getReserveBase(), 20000000) // 20 XRP
   })
 
   it('with proxy', function(done) {
@@ -378,7 +379,7 @@ describe('Connection', function() {
       throw new Error('error on reconnect')
     }
     // Hook up a listener for the reconnect error event
-    this.api.on('error', (error, message) => { 
+    this.api.on('error', (error, message) => {
       if(error === 'reconnect' && message === 'error on reconnect') {
         return done()
       }