feat(ngCookies): support SameSite option

Closes  #16543
Closes  #16544

Author: m-amr

src/ngCookies/cookieWriter.js

@@ -14,6 +14,11 @@
 function $$CookieWriter($document, $log, $browser) {
   var cookiePath = $browser.baseHref();
   var rawDocument = $document[0];
+  var sameSiteValidValues = ['lax', 'strict'];
+
+  function isSameSiteValueValid(val) {
+    return sameSiteValidValues.indexOf(val) >= 0;
+  }
 
   function buildCookieString(name, value, options) {
     var path, expires;
@@ -33,6 +38,7 @@ function $$CookieWriter($document, $log, $browser) {
     str += options.domain ? ';domain=' + options.domain : '';
     str += expires ? ';expires=' + expires.toUTCString() : '';
     str += options.secure ? ';secure' : '';
+    str += (options.SameSite && isSameSiteValueValid(options.SameSite)) ? ';SameSite=' + options.SameSite : '';
 
     // per http://www.ietf.org/rfc/rfc2109.txt browser must allow at minimum:
     // - 300 cookies

test/ngCookies/cookieWriterSpec.js

@@ -181,6 +181,21 @@ describe('cookie options', function() {
     expect(getLastCookieAssignment('secure')).toBe(true);
   });
 
+  it('should accept sameSite option when value is lax', function() {
+    $$cookieWriter('name', 'value', {SameSite: 'lax'});
+    expect(getLastCookieAssignment('SameSite')).toBe('lax');
+  });
+
+  it('should accept sameSite option when value is strict', function() {
+    $$cookieWriter('name', 'value', {SameSite: 'strict'});
+    expect(getLastCookieAssignment('SameSite')).toBe('strict');
+  });
+
+  it('should not accept sameSite option when value is invalid', function() {
+    $$cookieWriter('name', 'value', {SameSite: 'test'});
+    expect(getLastCookieAssignment('SameSite')).toBeUndefined();
+  });
+
   it('should accept expires option on set', function() {
     $$cookieWriter('name', 'value', {expires: 'Fri, 19 Dec 2014 00:00:00 GMT'});
     expect(getLastCookieAssignment('expires')).toMatch(/^Fri, 19 Dec 2014 00:00:00 (UTC|GMT)$/);