Enable new buffer to create recipe

Fixes #372

Author: julianhille

lib/Recipe.js

@@ -28,7 +28,9 @@ class Recipe {
     this.src = src;
     // detect the src is Buffer or not
     this.isBufferSrc = this.src instanceof Buffer;
-    this.isNewPDF = !this.isBufferSrc && src.toLowerCase() === "new";
+    this.isNewPDF =
+      (!this.isBufferSrc && src.toLowerCase() === "new") ||
+      (this.isBufferSrc && this.src.equals(Buffer.from("new")));
     this.encryptOptions = this._getEncryptOptions(options, this.isNewPDF);
     this.options = Object.assign({}, options, this.encryptOptions);
     this.current = {};
@@ -75,12 +77,21 @@ class Recipe {
 
   _createWriter() {
     if (this.isNewPDF) {
-      this.writer = muhammara.createWriter(
-        this.output,
-        Object.assign({}, this.encryptOptions, {
-          version: this._getVersion(this.options.version),
-        }),
-      );
+      if (!this.isBufferSrc) {
+        this.writer = muhammara.createWriter(
+          this.output,
+          Object.assign({}, this.encryptOptions, {
+            version: this._getVersion(this.options.version),
+          }),
+        );
+      } else {
+        this.writer = muhammara.createWriter(
+          new muhammara.PDFStreamForResponse(this.outStream),
+          Object.assign({}, this.encryptOptions, {
+            log: this.logFile,
+          }),
+        );
+      }
     } else {
       this.read();
       try {