fix(generateBurnOpReturn): SLP burn functionality

src/slp/tokentype1.js

@@ -118,7 +118,7 @@ class TokenType1 {
    *  - script: an array of Bufers that is ready to fed into bchjs.Script.encode() to be turned into a transaction output.
    *  - outputs: an integer with a value of 1. There is no token change to be sent with this transaction.
    */
-  generateBurnOpReturn(tokenUtxos, sendQty) {
+  generateBurnOpReturn(tokenUtxos, burnQty) {
     try {
       const tokenId = tokenUtxos[0].tokenId
       const decimals = tokenUtxos[0].decimals
@@ -128,44 +128,9 @@ class TokenType1 {
       for (let i = 0; i < tokenUtxos.length; i++)
         totalTokens += tokenUtxos[i].tokenQty
 
-      const change = totalTokens - sendQty
+      const remainder = totalTokens - burnQty
 
-      let script
-      let outputs = 1
-
-      // The normal case, when there is token change to return to sender.
-      if (change > 0) {
-        outputs = 2
-
-        let baseQty = new BigNumber(sendQty).times(10 ** decimals)
-        baseQty = baseQty.absoluteValue()
-        baseQty = Math.floor(baseQty)
-        let baseQtyHex = baseQty.toString(16)
-        baseQtyHex = baseQtyHex.padStart(16, "0")
-
-        let baseChange = new BigNumber(change).times(10 ** decimals)
-        baseChange = baseChange.absoluteValue()
-        baseChange = Math.floor(baseChange)
-        // console.log(`baseChange: ${baseChange.toString()}`)
-
-        let baseChangeHex = baseChange.toString(16)
-        baseChangeHex = baseChangeHex.padStart(16, "0")
-        // console.log(`baseChangeHex padded: ${baseChangeHex}`)
-
-        script = [
-          this.Script.opcodes.OP_RETURN,
-          Buffer.from("534c5000", "hex"),
-          //BITBOX.Script.opcodes.OP_1,
-          Buffer.from("01", "hex"),
-          Buffer.from(`SEND`),
-          Buffer.from(tokenId, "hex"),
-          Buffer.from(baseQtyHex, "hex"),
-          Buffer.from(baseChangeHex, "hex")
-        ]
-      } else {
-        // Corner case, when there is no token change to send back.
-
-        let baseQty = new BigNumber(sendQty).times(10 ** decimals)
+      let baseQty = new BigNumber(remainder).times(10 ** decimals)
       baseQty = baseQty.absoluteValue()
       baseQty = Math.floor(baseQty)
       let baseQtyHex = baseQty.toString(16)
@@ -173,7 +138,7 @@ class TokenType1 {
 
       // console.log(`baseQty: ${baseQty.toString()}`)
 
-        script = [
+      const script = [
         this.Script.opcodes.OP_RETURN,
         Buffer.from("534c5000", "hex"),
         //BITBOX.Script.opcodes.OP_1,
@@ -182,9 +147,8 @@ class TokenType1 {
         Buffer.from(tokenId, "hex"),
         Buffer.from(baseQtyHex, "hex")
       ]
-      }
 
-      return { script, outputs }
+      return script
     } catch (err) {
       console.log(`Error in generateSendOpReturn()`)
       throw err

test/unit/slp-tokentype1.js

@@ -107,6 +107,40 @@ describe("#SLP TokenType1", () => {
     //   })
   })
 
+  describe("#generateBurnOpReturn", () => {
+    it("should generate burn OP_RETURN code", async () => {
+      // Mock UTXO.
+      const tokenUtxos = [
+        {
+          txid:
+            "a8eb788b8ddda6faea00e6e2756624b8feb97655363d0400dd66839ea619d36e",
+          vout: 2,
+          value: "546",
+          confirmations: 0,
+          satoshis: 546,
+          utxoType: "token",
+          transactionType: "send",
+          tokenId:
+            "497291b8a1dfe69c8daea50677a3d31a5ef0e9484d8bebb610dac64bbc202fb7",
+          tokenTicker: "TOK-CH",
+          tokenName: "TokyoCash",
+          tokenDocumentUrl: "",
+          tokenDocumentHash: "",
+          decimals: 8,
+          tokenQty: 7
+        }
+      ]
+
+      const result = await bchjs.SLP.TokenType1.generateBurnOpReturn(
+        tokenUtxos,
+        1
+      )
+      // console.log(`result: ${JSON.stringify(result, null, 2)}`)
+
+      assert.isArray(result)
+    })
+  })
+
   describe("#generateGenesisOpReturn", () => {
     it("should generate genesis OP_RETURN code", async () => {
       const configObj = {