Attachment helper for base64 encoding

- If the content is a Buffer and the disposition is 'attachment', then
  the Buffer will be encoded to a base64 string;
- If a filePath is given, then file will be read and its content will be
  used, the rule to convert the file content to base64 is the same
  described above;
- It's not allowed to use content and filePath together;
- Added unit test for the new cases;

packages/helpers/classes/attachment.js

@@ -6,6 +6,8 @@
 const toCamelCase = require('../helpers/to-camel-case');
 const toSnakeCase = require('../helpers/to-snake-case');
 const deepClone = require('../helpers/deep-clone');
+const fs = require('fs');
+const path = require('path');
 
 /**
  * Attachment class
@@ -39,30 +41,67 @@ class Attachment {
     data = toCamelCase(data);
 
     //Extract properties from data
-    const {content, filename, type, disposition, contentId} = data;
+    const {
+      content,
+      filename,
+      type,
+      disposition,
+      contentId,
+      filePath
+    } = data;
+
+    if ((typeof content !== 'undefined') && (typeof filePath !== 'undefined')) {
+      throw new Error(
+        `The props 'content' and 'filePath' cannot be used together.`
+      );
+    }
 
     //Set data
-    this.setContent(content);
     this.setFilename(filename);
     this.setType(type);
     this.setDisposition(disposition);
     this.setContentId(contentId);
+    this.setContent(filePath ? this.readFile(filePath) : content);
+  }
+
+  /**
+   * Read a file and return its content as base64
+   */
+  readFile(filePath) {
+    return fs.readFileSync(path.resolve(filePath));
   }
 
   /**
    * Set content
    */
   setContent(content) {
     //Duck type check toString on content if it's a Buffer as that's the method that will be called.
-    if (typeof content === 'string') {      
+    if (typeof content === 'string') {
       this.content = content;
-    } else if (content instanceof Buffer && content.toString !== undefined) {      
+      return;
+    } else if (content instanceof Buffer && content.toString !== undefined) {
       this.content = content.toString();
-    } else {
-      throw new Error('`content` expected to be either Buffer or string');
+
+      if (this.disposition == 'attachment') {
+        this.content = content.toString('base64');
+      }
+
+      return;
+    }
+
+    throw new Error('`content` expected to be either Buffer or string');
+  }
+
+  /**
+   * Set content
+   */
+  setFileContent(content) {
+    if (content instanceof Buffer && content.toString !== undefined) {
+      this.content = content.toString('base64');
+      return;
     }
 
-    return;    
+    throw new Error('`content` expected to be Buffer');
   }
 
   /**

packages/helpers/classes/attachment.spec.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const fs = require('fs');
+const path = require('path');
 
 /**
  * Dependencies
@@ -18,15 +19,15 @@ describe('Attachment', function() {
 
   //Set content as string
   describe('setContent(), string', function() {
-    it('should set string as content', function() {      
+    it('should set string as content', function() {
       attachment.setContent("Just a string.");
       expect(attachment.content).to.equal('Just a string.');
     });
   });
 
   //Set content as stream
   describe('setContent(), stream', function() {
-    it('should convert stream to string and set as content', function() {      
+    it('should convert stream to string and set as content', function() {
       const fileData = fs.readFileSync('./packages/helpers/attachment.txt');
       attachment.setContent(fileData);
       expect(attachment.content).to.equal('Just a little file for testing attachments.');
@@ -35,9 +36,60 @@ describe('Attachment', function() {
 
   //Set content as wrong type
   describe('setContent(), wrong type', function() {
-    it('should not allow setting content of wrong type', function() {      
+    it('should not allow setting content of wrong type', function() {
       expect(() => attachment.setContent(null)).to.throw('`content` expected to be either Buffer or string');
     });
   });
 
+  //Constructor
+  describe('constructor(data)', function() {
+    it('should not accept both content and filePath', function() {
+      expect(function() {
+        attachment = new Attachment({
+          filename: 'attachment.txt',
+          type: 'plain/text',
+          disposition: 'attachment',
+          contentId: 'myattachment',
+          content: '',
+          filePath: ''
+        });
+      }).to.throw(Error);
+    });
+  });
+});
+
+//Set content
+describe('setContent()', function() {
+  let attachment;
+
+  beforeEach(function() {
+    attachment = new Attachment({
+      filename: 'attachment.txt',
+      type: 'plain/text',
+      disposition: 'attachment',
+      contentId: 'myattachment',
+      content: 'SGVsbG8gV29ybGQK',
+    });
+  });
+
+  it('should set the given value', function() {
+    expect(attachment.content).to.equal('SGVsbG8gV29ybGQK');
+  });
+
+  it('should accept a buffer', function() {
+    attachment.setContent(new Buffer("Hello World\n"));
+    expect(attachment.content).to.equal('SGVsbG8gV29ybGQK');
+  });
+
+  it('should accept a raw file', function() {
+    attachment = new Attachment({
+      filename: 'attachment.txt',
+      type: 'plain/text',
+      disposition: 'attachment',
+      contentId: 'myattachment',
+      filePath: path.resolve(__dirname + '/attachment.js')
+    });
+
+    expect(attachment.content).to.be.a('string');
+  });
 });