Add test cases for image Buffer

docs/image-format.md

@@ -11,3 +11,4 @@ On a browser, an image can be:
 
 In Node.js, an image can be
 - a path to a local image
+- a Buffer storing binary image 

scripts/test-helper.js

@@ -1,3 +1,4 @@
 global.expect = require('expect.js');
-global.fetch = require('node-fetch');
+global.fs = require('fs');
+global.path = require('path');
 global.Tesseract = require('../src');

src/node/index.js

@@ -25,6 +25,7 @@ const readFile = util.promisify(fs.readFile);
  * @access public
  * @param {string} image - image source, supported formats:
  *   string: URL string or file path
+ *   buffer: image buffer
  * @returns {array} binary image in array format
  */
 const loadImage = (image) => {
@@ -34,8 +35,12 @@ const loadImage = (image) => {
     })
       .then(resp => resp.data);
   }
-  if (Buffer.isBuffer( image) ) return new Promise(function(resolve, reject) { resolve(image); });
-  else return readFile(image);
+
+  if (Buffer.isBuffer(image)) {
+    return Promise.resolve(image);
+  }
+
+  return readFile(image);
 };
 
 /*

tests/recognize.test.js

@@ -116,6 +116,21 @@ describe('recognize()', () => {
     ));
   });
 
+  (isBrowser ? describe.skip : describe)('should recognize image in Buffer (Node.js only)', () => {
+    FORMATS.forEach(format => (
+      it(`support ${format} format`, (done) => {
+        const worker = getWorker();
+        worker
+          .recognize(fs.readFileSync(path.join(__dirname, 'assets', 'images', `simple.${format}`)))
+          .then(({ text }) => {
+            expect(text).to.be(SIMPLE_TEXT);
+            worker.terminate();
+            done();
+          });
+      }).timeout(10000)
+    ));
+  });
+
   (isBrowser ? describe : describe.skip)('should read image from img DOM element (browser only)', () => {
     FORMATS.forEach(format => (
       it(`support ${format} format`, (done) => {