[PLT-959] Browser Compatibility (#6945)

* Error page implimentation

* Update Browser Compatibility check to check Chrome, FF, IE, Edge, and Safai

* Update strings with proper edge version

* undo uneeded changes and move to go template.

* more unneeded additions

* eliminate js and add local triangle

* fix typo

* Correct debug logging of browser version

* Modify Browser Check to pass user_agent object only and write test.

* Fix chrome version typo and correct testing change that broke chrome UA chack

* simplity browser version detection by using maps instead of string splitting

web/web_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/store"
 	"github.com/mattermost/platform/utils"
+	"github.com/mssola/user_agent"
 )
 
 var ApiClient *model.Client
@@ -120,3 +121,31 @@ func TestZZWebTearDown(t *testing.T) {
 	time.Sleep(2 * time.Second)
 	TearDown()
 }
+
+func TestCheckBrowserCompatability(t *testing.T) {
+
+	//test should fail browser compatibility check with Mozilla FF 40.1
+	ua := "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.1"
+	t.Logf("Checking Mozzila 40.1 with U.A. String: \n%v", ua)
+	if result := CheckBrowserCompatability(user_agent.New(ua)); result == true {
+		t.Error("Fail: should have failed browser compatibility")
+	} else {
+		t.Log("Pass: User Agent correctly failed!")
+	}
+
+	ua = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36"
+	t.Logf("Checking Chrome 60 with U.A. String: \n%v", ua)
+	if result := CheckBrowserCompatability(user_agent.New(ua)); result == false {
+		t.Error("Fail: should have passed browser compatibility")
+	} else {
+		t.Log("Pass: User Agent correctly passed!")
+	}
+
+	ua = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393"
+	t.Logf("Checking Edge 14.14393 with U.A. String: \n%v", ua)
+	if result := CheckBrowserCompatability(user_agent.New(ua)); result == true {
+		t.Log("Warning: Edge should have failed browser compatibility. It is probably still detecting as Chrome.")
+	} else {
+		t.Log("Pass: User Agent correctly failed!")
+	}
+}