fix allowance in datatoken

src/datatokens/Datatokens.ts

@@ -159,7 +159,7 @@ export class DataTokens {
         dataTokenAddress: string,
         fromAddress: string,
         amount: number,
-        account: Account
+        account: string
     ): Promise<string> {
         const datatoken = new this.web3.eth.Contract(
             this.datatokensABI,
@@ -188,6 +188,21 @@ export class DataTokens {
         return trxReceipt
     }
 
+    /**
+     * 
+     * @param dataTokenAddress 
+     * @param account 
+     */
+    public async allowance(dataTokenAddress: string, owner: string, spender: string): Promise<string> {
+        const datatoken = new this.web3.eth.Contract(
+            this.datatokensABI,
+            dataTokenAddress,
+            { from: spender }
+        )
+        const trxReceipt = await datatoken.methods.allowance(owner, spender).call()
+        return trxReceipt
+    }
+
     /** Get Blob
      * @param {String} dataTokenAddress
      * @param {Account} account

test/integration/Marketplaceflow.test.ts

@@ -29,6 +29,7 @@ describe('Marketplace flow', () => {
 
     let ocean
 
+    const marketplaceAllowance = 20
     const tokenAmount = 100
     const transferAmount = 2
     const blob = 'http://localhost:8030/api/v1/provider/services'
@@ -89,13 +90,42 @@ describe('Marketplace flow', () => {
 
         it('Alice publishes a dataset', async () => {
             ddo = await ocean.assets.create(asset, alice, [], tokenAddress)
-            assert(ddo != null)
+            assert(ddo.dataToken === tokenAddress)
         })
 
         it('Alice mints 100 tokens', async () => {
             await datatoken.mint(tokenAddress, alice.getId(), tokenAmount)
         })
 
+        it('Alice allows marketplace to sell her datatokens', async () => {
+            await datatoken.approve(
+                tokenAddress,
+                marketplace.getId(),
+                marketplaceAllowance, 
+                alice.getId()
+            ).then(async () => {
+                const allowance = await datatoken.allowance(
+                    tokenAddress,
+                    alice.getId(),
+                    marketplace.getId()
+                )
+                assert(allowance.toString() === marketplaceAllowance.toString())
+            })
+        })
+
+        it('Marketplace withdraw Alice tokens from allowance', async () => {
+            const allowance = await datatoken.allowance(
+                tokenAddress,
+                alice.getId(),
+                marketplace.getId()
+            )
+            await datatoken.transferFrom(tokenAddress, alice.getId(), allowance, marketplace.getId())
+            .then(async () => {
+                const marketplaceBalance = await datatoken.balance(tokenAddress, marketplace.getId())
+                assert(marketplaceBalance.toString() === marketplaceAllowance.toString())
+            })
+        })
+
         // it('Marketplace posts asset for sale', async () => {
         //     const config = new Config()
         //     marketOcean = await Ocean.getInstance(config)