Merge pull request #530 from oceanprotocol/fix/pool-creation

pool creation: check allowance for dt and ocean before aprove is called

src/balancer/OceanPool.ts

@@ -94,52 +94,58 @@ export class OceanPool extends Pool {
   ): SubscribablePromise<PoolCreateProgressStep, TransactionReceipt> {
     if (this.oceanAddress == null) {
       this.logger.error('ERROR: oceanAddress is not defined')
-      return null
+      throw new Error('ERROR: oceanAddress is not defined')
     }
     if (parseFloat(fee) > 0.1) {
       this.logger.error('ERROR: Swap fee too high. The maximum allowed swapFee is 10%')
-      return null
+      throw new Error('ERROR: Swap fee too high. The maximum allowed swapFee is 10%')
     }
     if (parseFloat(dtAmount) < 2) {
       this.logger.error('ERROR: Amount of DT is too low')
-      return null
+      throw new Error('ERROR: Amount of DT is too low')
     }
     if (parseFloat(dtWeight) > 9 || parseFloat(dtWeight) < 1) {
       this.logger.error('ERROR: Weight out of bounds (min 1, max9)')
-      return null
+      throw new Error('ERROR: Weight out of bounds (min 1, max9)')
     }
     return new SubscribablePromise(async (observer) => {
       observer.next(PoolCreateProgressStep.CreatingPool)
       const createTxid = await super.createPool(account)
       if (!createTxid) {
-        this.logger.error('ERROR: Failed to call approve DT token')
-        return null
+        this.logger.error('ERROR: Failed to call create pool')
+        throw new Error('ERROR: Failed to call create pool')
       }
       const address = createTxid.events.BPoolRegistered.returnValues[0]
       const oceanWeight = 10 - parseFloat(dtWeight)
       this.dtAddress = dtAddress
-      observer.next(PoolCreateProgressStep.ApprovingDatatoken)
       let txid
-      txid = await this.approve(
-        account,
-        dtAddress,
-        address,
-        this.web3.utils.toWei(String(dtAmount))
-      )
-      if (!txid) {
-        this.logger.error('ERROR: Failed to call approve DT token')
-        return null
+      const dtAllowance = await this.allowance(dtAddress, account, address)
+      if (parseFloat(dtAllowance) < parseFloat(dtAmount)) {
+        observer.next(PoolCreateProgressStep.ApprovingDatatoken)
+        txid = await this.approve(
+          account,
+          dtAddress,
+          address,
+          this.web3.utils.toWei(String(dtAmount))
+        )
+        if (!txid) {
+          this.logger.error('ERROR: Failed to call approve DT token')
+          throw new Error('ERROR: Failed to call approve DT token')
+        }
       }
-      observer.next(PoolCreateProgressStep.ApprovingOcean)
-      txid = await this.approve(
-        account,
-        this.oceanAddress,
-        address,
-        this.web3.utils.toWei(String(oceanAmount))
-      )
-      if (!txid) {
-        this.logger.error('ERROR: Failed to call approve OCEAN token')
-        return null
+      const oceanAllowance = await this.allowance(this.oceanAddress, account, address)
+      if (parseFloat(oceanAllowance) < parseFloat(oceanAmount)) {
+        observer.next(PoolCreateProgressStep.ApprovingOcean)
+        txid = await this.approve(
+          account,
+          this.oceanAddress,
+          address,
+          this.web3.utils.toWei(String(oceanAmount))
+        )
+        if (!txid) {
+          this.logger.error('ERROR: Failed to call approve OCEAN token')
+          throw new Error('ERROR: Failed to call approve OCEAN token')
+        }
       }
       observer.next(PoolCreateProgressStep.SetupPool)
       txid = await super.setup(
@@ -155,7 +161,7 @@ export class OceanPool extends Pool {
       )
       if (!txid) {
         this.logger.error('ERROR: Failed to create a new pool')
-        return null
+        throw new Error('ERROR: Failed to create a new pool')
       }
       return createTxid
     })

src/balancer/Pool.ts

@@ -4,6 +4,7 @@ import { TransactionReceipt } from 'web3-core'
 import { Logger, getFairGasPrice } from '../utils'
 import BigNumber from 'bignumber.js'
 import jsonpoolABI from '@oceanprotocol/contracts/artifacts/BPool.json'
+import defaultDatatokensABI from '@oceanprotocol/contracts/artifacts/DataTokenTemplate.json'
 import { PoolFactory } from './PoolFactory'
 
 const MaxUint256 =
@@ -107,6 +108,25 @@ export class Pool extends PoolFactory {
     return result
   }
 
+  /**
+   * Get Alloance for both DataToken and Ocean
+   * @param {String } tokenAdress
+   * @param {String} owner
+   * @param {String} spender
+   */
+  public async allowance(
+    tokenAdress: string,
+    owner: string,
+    spender: string
+  ): Promise<string> {
+    const tokenAbi = defaultDatatokensABI.abi as AbiItem[]
+    const datatoken = new this.web3.eth.Contract(tokenAbi, tokenAdress, {
+      from: spender
+    })
+    const trxReceipt = await datatoken.methods.allowance(owner, spender).call()
+    return this.web3.utils.fromWei(trxReceipt)
+  }
+
   /**
    * Approve spender to spent amount tokens
    * @param {String} account