* final output writing added with prolog

* new string constant and options added for prolog
* README updated with new options

Author: lalugeo

README.md

@@ -66,6 +66,7 @@ Reporter options should also be strings exception for suiteNameTemplate, classNa
 | `JEST_JUNIT_TITLE` | Template string for the `name` attribute of `<testcase>`. | `"{classname} {title}"` | `{classname}`, `{title}`, `{filepath}`, `{filename}`, `{displayName}`
 | `JEST_JUNIT_ANCESTOR_SEPARATOR` | Character(s) used to join the `describe` blocks. | `" "` | N/A
 | `JEST_USE_PATH_FOR_SUITE_NAME` | **DEPRECATED. Use `suiteNameTemplate` instead.** Use file path as the `name` attribute of `<testsuite>` | `"false"` | N/A
+| `JEST_JUNIT_INCLUDE_XML_PROLOG` | Determines if the XML output contains the Prolog | `"false"` | N/A
 
 
 You can configure these options via the command line as seen below:
@@ -86,7 +87,8 @@ Or you can also define a `jest-junit` key in your `package.json`.  All are **str
     "classNameTemplate": "{classname}-{title}",
     "titleTemplate": "{classname}-{title}",
     "ancestorSeparator": " › ",
-    "usePathForSuiteName": "true"
+    "usePathForSuiteName": "true",
+    "includeXmlProlog": "false"
   }
 }
 ```

constants/index.js

@@ -13,6 +13,7 @@ module.exports = {
     JEST_JUNIT_TITLE: 'titleTemplate',
     JEST_JUNIT_ANCESTOR_SEPARATOR: 'ancestorSeparator',
     JEST_USE_PATH_FOR_SUITE_NAME: 'usePathForSuiteName',
+    JEST_JUNIT_INCLUDE_XML_PROLOG:'includeXmlProlog',
   },
   DEFAULT_OPTIONS: {
     suiteName: 'jest tests',
@@ -24,10 +25,12 @@ module.exports = {
     titleTemplate: '{classname} {title}',
     ancestorSeparator: ' ',
     usePathForSuiteName: 'false',
+    includeXmlProlog: 'false',
   },
   CLASSNAME_VAR: 'classname',
   FILENAME_VAR: 'filename',
   FILEPATH_VAR: 'filepath',
   TITLE_VAR: 'title',
   DISPLAY_NAME_VAR: 'displayName',
-};
+  XML_PROLOG_STRING: '<?xml version="1.0" encoding="UTF-8"?>',
+};

index.js

@@ -5,6 +5,7 @@ const mkdirp = require('mkdirp');
 const fs = require('fs');
 const path = require('path');
 const jestValidate = require('jest-validate');
+const constants = require('./constants');
 
 const buildJsonResults = require('./utils/buildJsonResults');
 const getOptions = require('./utils/getOptions');
@@ -25,7 +26,7 @@ const processor = (report, reporterOptions = {}, jestRootDir = null) => {
   mkdirp.sync(path.dirname(finalOutput));
 
   // Write data to file
-  fs.writeFileSync(finalOutput, xml(jsonResults, { indent: '  ' }));
+  fs.writeFileSync(finalOutput,(constants.XML_PROLOG === 'true')? constants.XML_PROLOG_STRING : '' + xml(jsonResults, { indent: '  ' }));
 
   // Jest 18 compatibility
   return report;
@@ -70,4 +71,3 @@ function JestJUnit (globalConfig, options) {
 }
 
 module.exports = JestJUnit;
-