Start unit testing code snippet contents service

Author: jahn96

test/codeSnippetContentsService.test.ts

@@ -0,0 +1,43 @@
+import { CodeSnippetContentsService } from '../src/CodeSnippetContentsService';
+
+const codeSnippetContentsService = CodeSnippetContentsService.getInstance();
+
+test('test getData', () => {
+  const res = {
+    name: 'sum_array',
+    description:
+      'Scala program of array. Declare, print, and calculate sum of all elements.',
+    language: 'Scala',
+    code: [
+      'object ExampleArray1 {',
+      '    ',
+      '   def main(args: Array[String]) {',
+      '       ',
+      '      var numbers = Array(10,20,30,40,50);',
+      '      var N:Int=0;',
+      '      ',
+      '      //print all array elements',
+      '      println("All array elements: ");',
+      '      for ( N <- numbers ) {',
+      '         println(N);',
+      '      }',
+      '      //calculating SUM of all elements',
+      '      var sum: Int=0;',
+      '      for ( N <- numbers ) {',
+      '         sum+=N;',
+      '      }      ',
+      '      println("Sum of all array elements: "+sum);',
+      '',
+      '   }',
+      '}'
+    ],
+    id: 11,
+    tags: ['math']
+  };
+  const data = codeSnippetContentsService.getData(
+    'snippets/sum_array.json',
+    'file'
+  );
+
+  data.then(val => expect(val).toBe(res));
+});