From 84b405afa800e91b2ef9a3697e4b628946c93cc4 Mon Sep 17 00:00:00 2001
From: Dustin Coffey <coffey.dustin@gmail.com>
Date: Sat, 27 Feb 2016 19:31:12 -0800
Subject: [PATCH] Add non-zero based numbering for outputImagePath.

---
 index.js           | 6 +++++-
 tests/test-main.js | 8 ++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index ee5dd64..1d9c9ca 100644
--- a/index.js
+++ b/index.js
@@ -18,6 +18,7 @@ function PDFImage(pdfFilePath, options) {
   this.useGM = options.graphicsMagick || false;
 
   this.outputDirectory = options.outputDirectory || path.dirname(pdfFilePath);
+  this.nonZeroBased = options.nonZeroBased || false;
 }
 
 PDFImage.prototype = {
@@ -60,9 +61,12 @@ PDFImage.prototype = {
     });
   },
   getOutputImagePathForPage: function (pageNumber) {
+    var fileName = this.pdfFileBaseName
+          + "-" + ((this.nonZeroBased) ? (~~pageNumber+1) : pageNumber)
+          + "." + this.convertExtension;
     return path.join(
       this.outputDirectory,
-      this.pdfFileBaseName + "-" + pageNumber + "." + this.convertExtension
+      fileName
     );
   },
   setConvertOptions: function (convertOptions) {
diff --git a/tests/test-main.js b/tests/test-main.js
index b5af150..17ff3dd 100644
--- a/tests/test-main.js
+++ b/tests/test-main.js
@@ -26,6 +26,14 @@ describe("PDFImage", function () {
       .equal("/tmp/test-1000.png");
   });
 
+  it("should return non-zero based page path", function () {
+    pdfImage = new PDFImage(pdfPath, { nonZeroBased: true });
+    expect(pdfImage.getOutputImagePathForPage(0))
+      .equal("/tmp/test-1.png");
+    expect(pdfImage.getOutputImagePathForPage(2))
+      .equal("/tmp/test-3.png");
+  });
+
   it("should return correct convert command", function () {
     expect(pdfImage.constructConvertCommandForPage(1))
       .equal("convert '/tmp/test.pdf[1]' '/tmp/test-1.png'");