fix: add conditional postgres test (#4)

* fix: add conditional postgres test

* fix: multi instance bug

.github/workflows/pr-validation.yml

@@ -77,4 +77,6 @@ jobs:
         run: protoc --go_out=. --go-grpc_out=. -I ./submodules/durabletask-protobuf/protos orchestrator_service.proto
 
       - name: Run integration tests
+        env:
+          POSTGRES_ENABLED: "true"
         run: go test ./tests/... -coverpkg ./api,./task,./client,./backend/...,./internal/helpers

backend/postgres/REAEDME.md

@@ -0,0 +1,3 @@
+# Postgres Backend
+### Testing
+By default, the postgres tests are skipped. To run the tests, set the environment variable `POSTGRES_ENABLED` to `true` before running the tests and have a postgres server running on `localhost:5432` with a database named `postgres` and a user `postgres` with password `postgres`.

tests/backend_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"github.com/microsoft/durabletask-go/backend/postgres"
+	"os"
 	"reflect"
 	"runtime"
 	"testing"
@@ -26,12 +27,21 @@ var (
 	sqliteFileOptions     = sqlite.NewSqliteOptions("test.sqlite3")
 )
 
-var backends = []backend.Backend{
-	sqlite.NewSqliteBackend(sqliteFileOptions, logger),
-	sqlite.NewSqliteBackend(sqliteInMemoryOptions, logger),
-	postgres.NewPostgresBackend(nil, logger), // Requires a local Postgres instance running with host=localhost, port=5432, user=postgres, password=postgres, dbname=postgres.
+func getRunnableBackends() []backend.Backend {
+	var runnableBackends []backend.Backend
+
+	runnableBackends = append(runnableBackends, sqlite.NewSqliteBackend(sqliteFileOptions, logger))
+	runnableBackends = append(runnableBackends, sqlite.NewSqliteBackend(sqliteInMemoryOptions, logger))
+
+	if os.Getenv("POSTGRES_ENABLED") == "true" {
+		runnableBackends = append(runnableBackends, postgres.NewPostgresBackend(nil, logger))
+	}
+
+	return runnableBackends
 }
 
+var backends = getRunnableBackends()
+
 var completionStatusValues = []protos.OrchestrationStatus{
 	protos.OrchestrationStatus_ORCHESTRATION_STATUS_COMPLETED,
 	protos.OrchestrationStatus_ORCHESTRATION_STATUS_TERMINATED,