Reed-Lab-03

lab-rob/.eslintignore

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+**/node_modules/*
+**/vendor/*
+**/*.min.js
+**/coverage/*
+**/build/*

lab-rob/.eslintrc.json

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+{
+    "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-rob/.gitignore

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+# 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/
+coverage/
+
+# 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
+
+node_modules/*
+coverage/*

lab-rob/README.md

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+# Code Fellows: Code 401d19: Full-Stack JavaScript
+## Lab 03: Asynchronous Callbacks / Parallel File Processing
+#### 11/29/17 - Robert Reed
+
+### reader.js
+reader.js exports a single function, `readFiles(paths, callback)`, that reads any number of files and pushes their contents, in order, to an array. 
+
+`paths` must be an array (there is no type check) containing the absolute paths to the files you would like to read. 
+
+If the file at a specified path does not exist, an error object is returned. 
+
+`callback` must be a function (again, no type checking) and should be in the following form: 
+
+```
+(error, data) => {
+  if(error)
+    // handle error
+  // do something with data
+}
+``` 
+
+`callback` should both handle the error object, as well as determine what to do with the final array.
+
+`readFiles()` is recursive, so be wary of memory usage.

lab-rob/__test__/reader.test.js

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+'use strict';
+
+const reader = require('../lib/reader');
+
+const rainText = `Rainy rain is the rainiest rain that rains.
+If you live in Seattle, get used to the rain!`;
+
+const snowText = `Clean snow is white, soft, and cold.
+Dirty snow can be brown, black, yellow, hard, and possibly dry.
+It doesn't really snow in Seattle that much.`;
+
+const sunText = `The sun is a rarity in Seattle. When it comes, it's great!
+Unfortunately, it rarely shines in the winter time.`;
+
+const rainPath = reader.getPath('rain.txt');
+
+const snowPath = reader.getPath('snow.txt');
+
+const sunPath = reader.getPath('sun.txt');
+
+describe('reader.js', () => {
+  describe('reader() should accept an array of text file names, and return an array with the text from those files, in the same order. If there is a filename error, an exception is thrown.', () => {
+    test('When three files names are given, an array with the text of each file should be returned.', done => {
+      reader.readFiles([rainPath, snowPath, sunPath], (err, data) => {
+        expect(err).toBeNull();
+        expect(data).toEqual([rainText, snowText, sunText]);
+        done();
+      });
+    });
+
+    test('When one filename is given, an array with the text of each file should be returned.', done => {
+      reader.readFiles([rainPath], (err, data) => {
+        expect(err).toBeNull();
+        expect(data).toEqual([rainText]);
+        done();
+      });
+    });
+
+    test('When no filename is given, an empty array should be returned.', done => {
+      reader.readFiles([], (err, data) => {
+        expect(err).toBeNull();
+        expect(data).toEqual([]);
+        done();
+      });
+    });
+
+    test('When 12 files names are given, an array with the text of each file should be returned.', done => {
+      reader.readFiles([rainPath, snowPath, sunPath, rainPath, snowPath, sunPath, rainPath, snowPath, sunPath, rainPath, snowPath, sunPath], (err, data) => {
+        expect(err).toBeNull();
+        expect(data).toEqual([rainText, snowText, sunText, rainText, snowText, sunText, rainText, snowText, sunText, rainText, snowText, sunText]);
+        done();
+      });
+    });
+
+    test('When a bad first filename is given, an error should be thrown.', done => {
+      reader.readFiles(['bad path', snowPath, sunPath], (err, data) => {
+        expect(err).not.toBeNull();
+        expect(data).toBeUndefined();
+        done();
+      });
+    });
+
+    test('When a bad second filename is given, an error should be thrown.', done => {
+      reader.readFiles([rainPath, 'snowPath', sunPath], (err, data) => {
+        expect(err).not.toBeNull();
+        expect(data).toBeUndefined();
+        done();
+      });
+    });
+
+    test('When a bad third filename is given, an error should be thrown.', done => {
+      reader.readFiles([rainPath, snowPath, 'sunPath'], (err, data) => {
+        expect(err).not.toBeNull();
+        expect(data).toBeUndefined();
+        done();
+      });
+    });
+
+    test('When a non-string is passed to the getPath method an error is thrown', () => {
+      expect(reader.getPath).toThrow();
+    });
+  });
+});

lab-rob/assets/rain.txt

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+Rainy rain is the rainiest rain that rains.
+If you live in Seattle, get used to the rain!

lab-rob/assets/snow.txt

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+Clean snow is white, soft, and cold.
+Dirty snow can be brown, black, yellow, hard, and possibly dry.
+It doesn't really snow in Seattle that much.

lab-rob/assets/sun.txt

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+The sun is a rarity in Seattle. When it comes, it's great!
+Unfortunately, it rarely shines in the winter time.

lab-rob/lib/reader.js

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+'use strict';
+
+const fs = require('fs');
+
+const reader = module.exports = {};
+
+reader.stringArray = [];
+
+// Recursively read files
+reader.readFiles = (paths, callback) => {
+  // base case - no more paths to read
+  //           - execute callback w/o error
+  if(paths.length === 0) {
+    callback(null, reader.stringArray);
+    reader.stringArray = [];
+  } else {
+    // still files to read
+    let filePath = paths.shift();
+    fs.readFile(filePath, (err, data) => {
+      // stop if there is an error
+      if (err)
+        return callback(err);
+
+      // Add the read data to the stringArray
+      reader.stringArray.push(data.toString());
+
+      // Recursively read the remaining files
+      reader.readFiles(paths, callback);
+    });
+  }
+};
+
+// get pathname to file via filename
+reader.getPath = fileName => {
+  if (typeof fileName !== 'string')
+    throw new TypeError(`Expected fileName to be a string, but got a ${typeof fileName}`);
+
+  return `${__dirname}/../assets/${fileName}`;
+};