Adding and checking for supported encodings in util function to avoid…

… exception (#205)

* Adding supported encodings

* Adding unit tests

* Undoing package-lock.json

lib/Util.ts

@@ -113,9 +113,9 @@ export function obtainContentCharset (response: IHttpClientResponse) : string {
   // |__ matches would be ['charset=utf-8', 'utf-8', index: 18, input: 'application/json; charset=utf-8']
   // |_____ matches[1] would have the charset :tada: , in our example it's utf-8
   // However, if the matches Array was empty or no charset found, 'utf-8' would be returned by default.
-
+  const nodeSupportedEncodings = ['ascii', 'utf8', 'utf16le', 'ucs2', 'base64', 'binary', 'hex'];
   const contentType: string = response.message.headers['content-type'] || '';
   const matches: (RegExpMatchArray|null) = contentType.match(/charset=([^;,\r\n]+)/i);
 
-  return (matches && matches[1]) ? matches[1] : 'utf-8';
+  return (matches && matches[1] && nodeSupportedEncodings.indexOf(matches[1]) != -1) ? matches[1] : 'utf-8';
 }

test/units/httptests.ts

@@ -234,6 +234,28 @@ describe('Http Tests', function () {
     assert(obj.source === "nock", "request should redirect to mocked missing");
     });
 
+    it('does basic http get request with server response having encoding supported by nodejs', async() => {
+        nock('http://microsoft.com')
+            .get('/')
+            .reply(200, 'Microsoft', {
+                'Content-Type': 'text/plain;charset=utf-8'
+            });
+        let res: httpm.HttpClientResponse = await _http.get('http://microsoft.com');
+        let body = await res.readBody();
+        assert(body == 'Microsoft', "response should be 'Microsoft'");
+    });
+
+    it('does basic http get request with server response having encoding not supported by nodejs', async() => {
+        nock('http://microsoft.com')
+            .get('/')
+            .reply(200, 'Microsoft', {
+                'Content-Type': 'text/plain;charset=us-ascii'
+            });
+        let res: httpm.HttpClientResponse = await _http.get('http://microsoft.com');
+        let body = await res.readBody();
+        assert(body == 'Microsoft', "response should be 'Microsoft'");
+    });
+
     it('does not follow redirects if disabled', async() => {
         nock('http://microsoft.com')
         .get('/redirect-to')