Adding more tests

test/models/http_request_models.dart

@@ -441,3 +441,28 @@ const httpRequestModelPost11 = HttpRequestModel(
 "text": "I LOVE Flutter"
 }""",
 );
+
+/// POST request model with default (utf-8) content type charset
+const httpRequestModelPost12 = HttpRequestModel(
+  method: HTTPVerb.post,
+  url: 'https://api.apidash.dev/case/lower',
+  bodyContentType: ContentType.json,
+  body: r"""{
+"text": "I LOVE Flutter"
+}""",
+);
+
+/// POST request model with charset override (latin1)
+const httpRequestModelPost13 = HttpRequestModel(
+  method: HTTPVerb.post,
+  url: 'https://api.apidash.dev/case/lower',
+  headers: [
+    NameValueModel(
+        name: 'Content-Type', value: 'application/json; charset=latin1'),
+  ],
+  isHeaderEnabledList: [true],
+  bodyContentType: ContentType.json,
+  body: r"""{
+"text": "I LOVE Flutter"
+}""",
+);

test/models/request_models.dart

@@ -233,8 +233,23 @@ const requestModelGetBadSSL = RequestModel(
   httpRequestModel: httpRequestModelGetBadSSL,
 );
 
+/// POST request model with content type override having no charset
 const requestModelPost11 = RequestModel(
   id: 'post11',
   apiType: APIType.rest,
   httpRequestModel: httpRequestModelPost11,
 );
+
+/// POST request model with default (utf-8) content type charset
+const requestModelPost12 = RequestModel(
+  id: 'post12',
+  apiType: APIType.rest,
+  httpRequestModel: httpRequestModelPost12,
+);
+
+/// POST request model with charset override (latin1)
+const requestModelPost13 = RequestModel(
+  id: 'post13',
+  apiType: APIType.rest,
+  httpRequestModel: httpRequestModelPost13,
+);

test/models/response_model_test.dart

@@ -62,6 +62,32 @@ void main() {
     expect(responseData.requestHeaders?['content-type'], 'application/json');
   });
 
+  test('Testing default contentType charset added by dart', () async {
+    var responseRec = await sendHttpRequest(
+      requestModelPost12.id,
+      requestModelPost12.apiType,
+      requestModelPost12.httpRequestModel!,
+    );
+
+    final responseData = responseModel.fromResponse(response: responseRec.$1!);
+    expect(responseData.statusCode, 200);
+    expect(responseData.requestHeaders?['content-type'],
+        'application/json; charset=utf-8');
+  });
+
+  test('Testing latin1 charset added by user', () async {
+    var responseRec = await sendHttpRequest(
+      requestModelPost13.id,
+      requestModelPost13.apiType,
+      requestModelPost13.httpRequestModel!,
+    );
+
+    final responseData = responseModel.fromResponse(response: responseRec.$1!);
+    expect(responseData.statusCode, 200);
+    expect(responseData.requestHeaders?['content-type'],
+        'application/json; charset=latin1');
+  });
+
   test('Testing fromResponse for Bad SSL with certificate check', () async {
     var responseRec = await sendHttpRequest(
       requestModelGetBadSSL.id,