Problem solving

.gitignore

@@ -0,0 +1,148 @@
+# Created by https://www.gitignore.io/api/osx,vim,node,linux,windows,visualstudiocode
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Typescript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+
+### OSX ###
+*.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### Vim ###
+# swap
+[._]*.s[a-v][a-z]
+[._]*.sw[a-p]
+[._]s[a-v][a-z]
+[._]sw[a-p]
+# session
+Session.vim
+# temporary
+.netrwhist
+# auto-generated tag files
+tags
+
+### VisualStudioCode ###
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+.history
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+ehthumbs.db
+ehthumbs_vista.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# End of https://www.gitignore.io/api/osx,vim,node,linux,windows,visualstudiocode

README.md

@@ -12,10 +12,10 @@
 * [Bitmap Specification](https://en.wikipedia.org/wiki/BMP_file_format)
 * [Buffer Docs](https://nodejs.org/api/buffer.html)
 
-## Configuration 
+## Configuration
 Configure the root of your repository with the following files and directories. Thoughfully name and organize any aditional configuration or module files.
 * **README.md** - contains documentation
-* **.gitignore** - contains a [robust](http://gitignore.io) `.gitignore` file 
+* **.gitignore** - contains a [robust](http://gitignore.io) `.gitignore` file
 * **.eslintrc.json** - contains the course linter configuratoin
 * **.eslintignore** - contains the course linter ignore configuration
 * **package.json** - contains npm package config
@@ -30,37 +30,36 @@ For this assignment you will be building a bitmap (`.bmp`) transformer CLI. It w
 
 #### Minimum Requirements
 * The CLI should be architected using best modularization practices
-* The CLI should require at least three arguments `input-file-path output-file-path transfrom-name` 
+* The CLI should require at least three arguments `input-file-path output-file-path transfrom-name`
 * The CLI should support a minimum of three transforms
 * The CLI should log useful Error messages if used incorrectly
 * The CLI should log a success message on completion
 
-## Testing 
-* Use TDD `describe` and `test` methods to define descriptive tests and increase readablity
+## Testing
+* Use TDD `describe` and `test` methods to define descriptive tests and increase readability
 * Each `test` callback should aim to test a small well defined feature of a function
 * Write tests to ensure each function behaves correctly with valid and invalid inputs
 * The CLI should be tested without using `child_process` or any equivilant third party libraries
 
 ##  Documentation
-In your README.md describe the exported values of each module you have defined. Every function description should include it's arity (expected number of paramiters), the expected data for each parameter (data-type and limitations), and it's behavior (for both valid and invalid use). Feel free to write any additional information in your README.md.
+In your README.md describe the exported values of each module you have defined. Every function description should include it's arity (expected number of parameters), the expected data for each parameter (data-type and limitations), and it's behavior (for both valid and invalid use). Feel free to write any additional information in your README.md.
 
 ## Tips
 You will want to define a strategy for solving the problem before you begin to code. Once you have a strategy defined, you can break it down into steps that can be split into helper modules. Each helper module should solve a small specific problem. The main module should utilize the helper modules to execute your original strategy.
 
-###### Example Strategy 
+###### Example Strategy
 0. Gather user input (infile, outfile, and transform)
-0. Read the input bitmap file using the fs module 
+0. Read the input bitmap file using the fs module
 0. Parse the bitmap's buffer into object representing a bitmap (using a constructor)
 0. Using metadata from the parsed bitmap object to run a transform on the buffer directly (mutate the colors)
 0. Write the mutated buffer to the output file path
 
 ###### Transfrom Ideas
-* Color Palette Transforms 
-  * Invert 
+* Color Palette Transforms
+  * Invert
   * Randomize
   * Greyscale
   * Black and White
   * Darken or Lighten
   * Add or Mutiply a Hue
   * Add or Subtract Contrast
-

lab-shannon/.eslintignore

@@ -0,0 +1,5 @@
+**/node_modules/*
+**/vendor/*
+**/*.min.js
+**/coverage/*
+**/build/*

lab-shannon/.eslintrc.json

@@ -0,0 +1,26 @@
+{
+  "env": {
+    "browser": true,
+    "node": true,
+    "commonjs": true,
+    "jest": true,
+    "es6": true
+  },
+  "globals": {
+    "err": true,
+    "req": true,
+    "res": true,
+    "next": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "sourceType": "module"
+  },
+  "rules": {
+    "no-console": "off",
+    "indent": [ "error", 2 ],
+    "quotes": ["error", "single", { "allowTemplateLiterals": true }],
+    "comma-dangle": ["error", "always-multiline"],
+    "semi": [ "error", "always" ]
+  }
+}

lab-shannon/README.md

@@ -0,0 +1 @@
+The program alters an image (bmp format) using one of three provided transformation types and saves the new image as a different file. Three parameters are required: the file path of the image to be altered (must be a .bmp format), the desired output file path (with .bmp extension), and the name of the transform desired (invert, randomize, or greyscale). If a parameter is not supplied the program will return an error. If the transformation type is not one of the three provided an error will be thrown and no new image will be created.

lab-shannon/__test__/bitmapTransformer.test.js

@@ -0,0 +1,34 @@
+'use strict';
+
+const imageTransformer = require(`../lib/imageTransformer.js`);
+
+let args;
+
+describe(`bitmapTransformer.js`, () => {
+  test(`imageTransformer.transformImage should return an edited image based on the transform operation provided if no errors are present`, () => {
+    expect(() => {
+      args = [`house.bmp`,`invert.bmp`,`invert`];
+      imageTransformer.transformImage(...args);
+    }).not.toThrow();
+    expect(() => {
+      args = [`house.bmp`,`greyscale.bmp`,`greyscale`];
+      imageTransformer.transformImage(...args);
+    }).not.toThrow();
+    expect(() => {
+      args = [`house.bmp`,`randomize.bmp`,`randomize`];
+      imageTransformer.transformImage(...args);
+    }).not.toThrow();
+  });
+  test(`imageTransformer.transformImage should return an error if the transform type provided is not one of the three options`, () => {
+    expect(() => {
+      args = [`house.bmp`,`randomize.bmp`,[blah]];
+      imageTransformer.transformImage(...args);
+    }).toThrow();
+  });
+  test(`imageTransformer.transformImage should return an error if fewer than three parameters are provided`, () => {
+    expect(() => {
+      args = [`house.bmp`,`randomize.bmp`];
+      imageTransformer.transformImage(...args);
+    }).toThrow();
+  });
+});

lab-shannon/index.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const bitmapTransformer = require(`./lib/bitmapTransformer`);
+const imageTransformer = require(`./lib/imageTransformer`);
+const indexJS = module.exports = {};
+
+let args = process.argv.slice(2);
+
+imageTransformer.transformImage(args[0], args[1], args.slice(2));

lab-shannon/lib/bitmapTransformer.js

@@ -0,0 +1,69 @@
+'use strict';
+
+const fs = require(`fs`);
+const bitmapTransformer = module.exports = {};
+
+const BITMAP_FILE_HEADER_SIZE = 14; //in bytes
+const DIB_HEADER_SIZE = 40; //in bytes
+const COLOR_PALETTE_OFFSET = (BITMAP_FILE_HEADER_SIZE + DIB_HEADER_SIZE); //offset of where color palette starts
+const PIXEL_TABLE_OFFSET = 10; //gives the offset of where the pixel data starts (i.e. end of color palette)
+
+bitmapTransformer.readFile = (pathOfInput, callback) => {
+  fs.readFile(`${__dirname}/../asset/${pathOfInput}`,
+    (error, data) => {
+      if (error)
+        console.error(error);
+
+      callback(data);
+    }
+  );
+};
+
+bitmapTransformer.getColorPalette = (buffer) => {
+  let parsedBitmap = {};
+  parsedBitmap.buffer = buffer;
+  buffer.pixelTableOffset = buffer.readInt32LE(PIXEL_TABLE_OFFSET);
+  parsedBitmap.colorPalette = buffer.slice(COLOR_PALETTE_OFFSET, buffer.pixelTableOffset);
+
+  return parsedBitmap;
+};
+
+bitmapTransformer.renderNewFile = (outputPath, parsedBitmapData) => {
+  fs.writeFile(outputPath, parsedBitmapData, (error) => {
+    if (error)
+      console.error(error);
+  });
+};
+
+
+bitmapTransformer.greyscale = (colorPalette) => {
+  //Luminosity based grayscale: gray value = 0.21 × R + 0.72 × G + 0.07 × B
+  for (let i = 0; i < colorPalette.length; i += 4){
+    let weightedGrayscaleAvg = (colorPalette[i] * .11) + (colorPalette[i + 1] * .59) + (colorPalette[i + 2] * .3);
+    colorPalette[i] = weightedGrayscaleAvg;
+    colorPalette[i + 1] = weightedGrayscaleAvg;
+    colorPalette[i + 2] = weightedGrayscaleAvg;
+  }
+};
+
+bitmapTransformer.invert = (colorPalette) => {
+  //change blue values
+  for (let i = 0; i < colorPalette.length; i += 4){
+    // try to use .fill instead  // colorPalette.fill(255 - colorPalette[i], 0);
+    colorPalette[i] = 255 - colorPalette[i];
+  }
+  //change green
+  for (let i = 1; i < colorPalette.length; i += 4){
+    colorPalette[i] = 255 - colorPalette[i];
+  }
+  //change red
+  for (let i = 2; i < colorPalette.length; i += 4){
+    colorPalette[i] = 255 - colorPalette[i];
+  }
+};
+
+bitmapTransformer.randomize = (colorPalette) => {
+  for (let i = 0; i < colorPalette.length; i += 4){
+    colorPalette[i] = Math.floor(Math.random() * 255);
+  }
+};

lab-shannon/lib/imageTransformer.js

@@ -0,0 +1,33 @@
+'use strict';
+
+const bitmapTransformer = require(`./bitmapTransformer`);
+const imageTransformer = module.exports = {};
+
+imageTransformer.transformImage = (inputPath, outputPath, transforms) => {
+  if(!inputPath || !outputPath || transforms.length < 1){
+    throw new Error(`Please provide an input path, an output path, and at least one transformation type`);
+  }
+
+  bitmapTransformer.readFile(inputPath, (data) => {
+    let parsedBitmap = bitmapTransformer.getColorPalette(data);
+
+    for(let i = 0; i < transforms.length; i++){
+      if(transforms[i] === `greyscale`) {
+        bitmapTransformer.greyscale(parsedBitmap.colorPalette);
+      }
+      else if(transforms[i] === `randomize`){
+        bitmapTransformer.randomize(parsedBitmap.colorPalette);
+      }
+      else if(transforms[i] === `invert`){
+        bitmapTransformer.invert(parsedBitmap.colorPalette);
+      }
+      else{
+        throw new ReferenceError(`The transformation type must be 'invert', 'greyscale', or 'randomize'`);
+      }
+    }
+
+    bitmapTransformer.renderNewFile(outputPath, parsedBitmap.buffer);
+
+    console.log(`Success! Your new image has been created`);
+  });
+};