From 54dc08b688cc3621c660c355cf121c40f0acac75 Mon Sep 17 00:00:00 2001
From: Arun Rajput <arunrajput@Aruns-MacBook-Pro-2.local>
Date: Sat, 27 Aug 2022 09:21:52 +0530
Subject: [PATCH] fix: variable binary field encode decode as hex

---
 lib/pack/assemble0_127_Fields.js | 39 ++++++++++++++++++++++++--------
 lib/unpack/unpack_0_127.js       |  6 ++++-
 test/8583-ext.js                 | 30 ++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 11 deletions(-)
 create mode 100644 test/8583-ext.js

diff --git a/lib/pack/assemble0_127_Fields.js b/lib/pack/assemble0_127_Fields.js
index 1cba89a..cb5b35d 100644
--- a/lib/pack/assemble0_127_Fields.js
+++ b/lib/pack/assemble0_127_Fields.js
@@ -90,17 +90,36 @@ function assemble0_127_Fields () {
             if (thisLen === 0) {
               return T.toErrorObject(['field', field, ' has no field implementation']);
             } else {
-              let actualLength = this.Msg[field].length;
-              let padCount = thisLen - actualLength.toString().length;
-              let lenIndicator = actualLength.toString();
-              for (let i = 0; i < padCount; i++) {
-                lenIndicator = 0 + lenIndicator;
+
+              if (this_format.ContentType === 'b') {
+
+                let actualLength = this.Msg[field].length/2;
+
+                let padCount = thisLen - actualLength.toString().length;
+                let lenIndicator = actualLength.toString();
+                for (let i = 0; i < padCount; i++) {
+                  lenIndicator = 0 + lenIndicator;
+                }
+                
+                let thisBuff = Buffer.alloc(actualLength, this.Msg[field], 'hex');
+                thisBuff = Buffer.concat([Buffer.from(lenIndicator), thisBuff]);
+                buff = Buffer.concat([buff, thisBuff]);
+
+
+              } else {
+                let actualLength = this.Msg[field].length;
+
+                let padCount = thisLen - actualLength.toString().length;
+                let lenIndicator = actualLength.toString();
+                for (let i = 0; i < padCount; i++) {
+                  lenIndicator = 0 + lenIndicator;
+                }
+                let thisBuff = Buffer.alloc(
+                  this.Msg[field].length + lenIndicator.length,
+                  lenIndicator + this.Msg[field]
+                );
+                buff = Buffer.concat([buff, thisBuff]);
               }
-              let thisBuff = Buffer.alloc(
-                this.Msg[field].length + lenIndicator.length,
-                lenIndicator + this.Msg[field]
-              );
-              buff = Buffer.concat([buff, thisBuff]);
             }
           }
         } else {
diff --git a/lib/unpack/unpack_0_127.js b/lib/unpack/unpack_0_127.js
index 5d906ca..f9aa3fe 100644
--- a/lib/unpack/unpack_0_127.js
+++ b/lib/unpack/unpack_0_127.js
@@ -93,7 +93,11 @@ module.exports = function (incoming, isoJSON, config) {
             } else {
               let len = thisBuff.slice(0, thisLen).toString();
               thisBuff = thisBuff.slice(thisLen, thisBuff.byteLength);
-              isoJSON[field] = thisBuff.slice(0, Number(len)).toString();
+              if (this_format.ContentType === 'b') {
+                isoJSON[field] = thisBuff.slice(0, Number(len)).toString('hex').toUpperCase();
+              } else {
+                isoJSON[field] = thisBuff.slice(0, Number(len)).toString();
+              }
               thisBuff = thisBuff.slice(Number(len), thisBuff.byteLength);
             }
           }
diff --git a/test/8583-ext.js b/test/8583-ext.js
new file mode 100644
index 0000000..efc5a9b
--- /dev/null
+++ b/test/8583-ext.js
@@ -0,0 +1,30 @@
+import test from 'ava';
+import iso8583 from '../lib/8583.js';
+
+/*
+Support custom iso 8583 formats
+Support Case: Binary var field encode decode
+*/
+test('iso8583 Ext - binary var field must be encoded', t => {
+  const format = {
+    2: {
+      ContentType: 'b',
+      Label: 'F1',
+      LenType: 'llvar',
+      MaxLen: 99
+    },
+        
+  };
+  const data = {
+    0: '0800',
+    '2': '1004000000000000303030303030303030343048' 
+    // #2 this is prepard by encodng subfields - 8bytes bitmap followed by subfields data
+  };
+  let isopack = new iso8583(data, format);
+  let buff = isopack.getRawMessage();
+  const iso1 = new iso8583(undefined, format).getIsoJSON(buff, {lenHeader: false});
+  t.deepEqual(iso1, data);
+  let isopack1 = new iso8583(iso1);
+  t.is(isopack1.Msg['2'], '1004000000000000303030303030303030343048');
+
+});