Lab dalton

__test__/bitmap.test.js

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+'use strict';
+
+const bitmap = require('../lib/bitmap');
+const fs = require('fs');
+
+describe('lib/bitmap.js', () => {
+
+  describe('testing for valid bitmap details', () => {
+    test('testing to see that we are receiving expected file paths ', done => {
+      fs.readFile(`${__dirname}/asset/house.bmp`, (error, data) => {
+        let parsedBitmap = bitmap.parseBitmap(data);
+        expect(error).toBeNull();
+        expect(parsedBitmap).not.toBeNull();
+        done();
+      });
+    });
+    test('testing to see that bitmap offsets are correct ', done => {
+      fs.readFile(`${__dirname}/asset/house.bmp`, (error, data) => {
+        let parsedBitmap = bitmap.parseBitmap(data);
+        expect(error).toBeNull();
+        expect(parsedBitmap.fileSize).toEqual(66616);
+        expect(parsedBitmap.type).toEqual('BM');
+        expect(parsedBitmap.pixelTableOffset).toEqual(1078);
+        expect(parsedBitmap.height).toEqual(256);
+        done();
+      });
+    });
+  });
+});

index.js

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+'use strict';
+
+const bitmap = require('./lib/bitmap');
+const fs = require('fs');
+
+fs.readFile(`${__dirname}/asset/house.bmp`, (error,data) => {
+  if(error)
+  {
+    console.error(error);
+    return;
+  }
+
+  let parsedBitmap = bitmap.parseBitmap(data);
+  console.log(parsedBitmap);
+
+  fs.writeFile(`${__dirname}/asset/houseTest.bmp`, data, error => {
+    if(error)
+    {
+      console.error(error);
+      return;
+    }
+  });
+});
+

lib/bitmap.js

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+'use strict';
+
+const bitmap = module.exports = {};
+
+
+bitmap.parseBitmap = (buffer) => {
+    let parsedBitmap = {};
+
+    const HEIGHT_OFFSET = 22;
+    const PIXEL_TABLE_OFFSET = 10;
+    const FILE_SIZE_OFFSET = 2;
+
+    parsedBitmap.buffer = buffer;
+    parsedBitmap.type = buffer.toString('utf-8',0,2);
+    parsedBitmap.fileSize = buffer.readInt32LE(FILE_SIZE_OFFSET);
+    parsedBitmap.pixelTableOffset = buffer.readInt32LE(PIXEL_TABLE_OFFSET);
+    parsedBitmap.height = buffer.readInt32LE(HEIGHT_OFFSET);
+    parsedBitmap.colorTable = buffer.slice(54, 1077);
+    parsedBitmap.colorTable.forEach((value, position, array) => {
+
+      if(position % 4 === 1) {
+        parsedBitmap.colorTable.writeUInt8(array[position-1], position);    
+      }
+      if (position % 4 === 2) {
+        parsedBitmap.colorTable.writeUInt8(array[position - 2], position);
+      }
+      if (position % 4 === 3) {
+        parsedBitmap.colorTable.writeUInt8(array[position - 3], position);
+      }
+    });
+    console.log(parsedBitmap.colorTable = buffer.slice(57, 1077));
+    console.log(parsedBitmap);
+    return parsedBitmap;
+  };