[MM-62408] Server Code Coverage with Fully Parallel Tests (#30078)

* TestPool

* Store infra

* Store tests updates

* Bump maximum concurrent postgres connections

* More infra

* channels/jobs

* channels/app

* channels/api4

* Protect i18n from concurrent access

* Replace some use of os.Setenv

* Remove debug

* Lint fixes

* Fix more linting

* Fix test

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix merge

* [MM-62408] Add CI job to generate test coverage (#30284)

* Add CI job to generate test coverage

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix more Setenv usage

* Fix more potential flakyness

* Remove parallelism from flaky test

* Remove conflicting env var

* Fix

* Disable parallelism

* Test atomic covermode

* Disable parallelism

* Enable parallelism

* Add upload coverage step

* Fix codecov.yml

* Add codecov.yml

* Remove redundant workspace field

* Add Parallel() util methods and refactor

* Fix formatting

* More formatting fixes

* Fix reporting

server/channels/app/platform/web_hub_test.go

@@ -60,6 +60,7 @@ func registerDummyWebConn(t *testing.T, th *TestHelper, addr net.Addr, session *
 }
 
 func TestHubStopWithMultipleConnections(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -84,6 +85,7 @@ func TestHubStopWithMultipleConnections(t *testing.T) {
 // TestHubStopRaceCondition verifies that attempts to use the hub after it has shutdown does not
 // block the caller indefinitely.
 func TestHubStopRaceCondition(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.Service.Store.Close()
 	// We do not call TearDown because th.TearDown shuts down the hub again. And hub close is not idempotent.
@@ -131,6 +133,7 @@ func TestHubStopRaceCondition(t *testing.T) {
 }
 
 func TestHubSessionRevokeRace(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t)
 	defer th.TearDown()
 
@@ -184,6 +187,7 @@ func TestHubSessionRevokeRace(t *testing.T) {
 }
 
 func TestHubConnIndex(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -435,6 +439,7 @@ func TestHubConnIndex(t *testing.T) {
 }
 
 func TestHubConnIndexIncorrectRemoval(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t)
 	defer th.TearDown()
 
@@ -485,6 +490,7 @@ func TestHubConnIndexIncorrectRemoval(t *testing.T) {
 }
 
 func TestHubConnIndexInactive(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t)
 	defer th.TearDown()
 
@@ -549,6 +555,7 @@ func TestHubConnIndexInactive(t *testing.T) {
 }
 
 func TestReliableWebSocketSend(t *testing.T) {
+	mainHelper.Parallel(t)
 	testCluster := &testlib.FakeClusterInterface{}
 
 	th := SetupWithCluster(t, testCluster)
@@ -584,6 +591,7 @@ func TestReliableWebSocketSend(t *testing.T) {
 }
 
 func TestHubIsRegistered(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -620,6 +628,7 @@ func TestHubIsRegistered(t *testing.T) {
 }
 
 func TestHubWebConnCount(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -841,6 +850,7 @@ func BenchmarkHubConnIndex(b *testing.B) {
 }
 
 func TestHubConnIndexRemoveMemLeak(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t)
 	defer th.TearDown()
 
@@ -893,6 +903,7 @@ func BenchmarkGetHubForUserId(b *testing.B) {
 }
 
 func TestClusterBroadcast(t *testing.T) {
+	mainHelper.Parallel(t)
 	testCluster := &testlib.FakeClusterInterface{}
 
 	th := SetupWithCluster(t, testCluster)
@@ -921,6 +932,7 @@ func TestClusterBroadcast(t *testing.T) {
 }
 
 func TestClusterBroadcastHooks(t *testing.T) {
+	mainHelper.Parallel(t)
 	t.Run("should send broadcast hook information across cluster", func(t *testing.T) {
 		testCluster := &testlib.FakeClusterInterface{}