Emit buffer for fields

README.md

@@ -141,6 +141,8 @@ http.createServer((req, res) => {
 
     * **preservePath** - _boolean_ - If paths in filenames from file parts in a `'multipart/form-data'` request shall be preserved. **Default:** `false`.
 
+    * **bufferOutput** - _boolean_ - If provided, fields part will be emitted as Buffer and not as text. **Default:** `false`.
+
     * **limits** - _object_ - Various limits on incoming data. Valid properties are:
 
         * **fieldNameSize** - _integer_ - Max field name size (in bytes). **Default:** `100`.

lib/index.js

@@ -22,6 +22,7 @@ function getInstance(cfg) {
       defCharset: undefined,
       defParamCharset: undefined,
       preservePath: false,
+      bufferOutput: false,
     };
     if (cfg.highWaterMark)
       instanceCfg.highWaterMark = cfg.highWaterMark;
@@ -30,6 +31,7 @@ function getInstance(cfg) {
     instanceCfg.defCharset = cfg.defCharset;
     instanceCfg.defParamCharset = cfg.defParamCharset;
     instanceCfg.preservePath = cfg.preservePath;
+    instanceCfg.bufferOutput = cfg.bufferOutput;
     return new type(instanceCfg);
   }
 

lib/types/multipart.js

@@ -239,6 +239,7 @@ class Multipart extends Writable {
                           : nullDecoder);
     const defCharset = (cfg.defCharset || 'utf8');
     const preservePath = cfg.preservePath;
+    const bufferOutput = cfg.bufferOutput;
     const fileOpts = {
       autoDestroy: true,
       emitClose: true,
@@ -520,17 +521,21 @@ retrydata:
           let data;
           switch (field.length) {
             case 0:
-              data = '';
+              data = bufferOutput ? null : '';
               break;
             case 1:
-              data = convertToUTF8(field[0], partCharset, 0);
+              data = bufferOutput
+                ? field[0]
+                : convertToUTF8(field[0], partCharset, 0);
               break;
             default:
-              data = convertToUTF8(
-                Buffer.concat(field, fieldSize),
-                partCharset,
-                0
-              );
+              data = bufferOutput
+                ? Buffer.concat(field, fieldSize)
+                : convertToUTF8(
+                    Buffer.concat(field, fieldSize),
+                    partCharset,
+                    0
+                  );
           }
           field = undefined;
           fieldSize = 0;

test/test-types-multipart-buffers.js

@@ -0,0 +1,94 @@
+'use strict';
+
+const assert = require('assert');
+const { inspect } = require('util');
+
+const { mustCall } = require(`${__dirname}/common.js`);
+
+const busboy = require('../lib');
+
+const input = Buffer.from([
+  '-----------------------------paZqsnEHRufoShdX6fh0lUhXBP4k',
+ 'Content-Disposition: form-data; '
+   + 'name="content"',
+ 'Content-Type: text/plain',
+ '',
+ 'A'.repeat(1023),
+ '-----------------------------paZqsnEHRufoShdX6fh0lUhXBP4k--'
+].join('\r\n'));
+const boundary = '---------------------------paZqsnEHRufoShdX6fh0lUhXBP4k';
+const expected = [
+  { type: 'field',
+    name: 'content',
+    val: Buffer.from('A'.repeat(1023)),
+    info: {
+      nameTruncated: false,
+      valueTruncated: false,
+      encoding: '7bit',
+      mimeType: 'text/plain',
+    },
+  },
+];
+const bb = busboy({
+  headers: {
+    'content-type': `multipart/form-data; boundary=${boundary}`,
+  },
+  bufferOutput: true
+});
+const results = [];
+
+bb.on('field', (name, val, info) => {
+  results.push({ type: 'field', name, val, info });
+});
+
+bb.on('file', (name, stream, info) => {
+  const data = [];
+  let nb = 0;
+  const file = {
+    type: 'file',
+    name,
+    data: null,
+    info,
+    limited: false,
+  };
+  results.push(file);
+  stream.on('data', (d) => {
+    data.push(d);
+    nb += d.length;
+  }).on('limit', () => {
+    file.limited = true;
+  }).on('close', () => {
+    file.data = Buffer.concat(data, nb);
+    assert.strictEqual(stream.truncated, file.limited);
+  }).once('error', (err) => {
+    file.err = err.message;
+  });
+});
+
+bb.on('error', (err) => {
+  results.push({ error: err.message });
+});
+
+bb.on('partsLimit', () => {
+  results.push('partsLimit');
+});
+
+bb.on('filesLimit', () => {
+  results.push('filesLimit');
+});
+
+bb.on('fieldsLimit', () => {
+  results.push('fieldsLimit');
+});
+
+bb.on('close', mustCall(() => {
+  assert.deepStrictEqual(
+    results,
+    expected,
+    'Results mismatch.\n'
+      + `Parsed: ${inspect(results)}\n`
+      + `Expected: ${inspect(expected)}`
+  );
+}));
+
+bb.end(input);