pool: Leave failed postgres db state in pool tests.

This modifies the pool tests to avoid cleaning up the postgres data when
there is a test failure and the -failfast test flag is set so the
contents of the database can be examined.

Since a failed run with -failfast will no longer purge the data, it also
adds logic to purge the data prior to running the tests to ensure any
previous failed runs are cleaned up on subsequent runs.

pool/pool_test.go

@@ -5,6 +5,7 @@
 package pool
 
 import (
+	"flag"
 	"os"
 	"testing"
 
@@ -73,6 +74,17 @@ func teardownBoltDB(db *BoltDB, dbPath string) error {
 	return os.Remove(dbPath)
 }
 
+// isFailFastSet returns whether or not the failfast test flag is set.
+func isFailFastSet() bool {
+	failfastFlag := flag.Lookup("test.failfast")
+	if failfastFlag == nil {
+		return false
+	}
+	failfast := failfastFlag.Value.(flag.Getter).Get()
+	isSet, ok := failfast.(bool)
+	return ok && isSet
+}
+
 // TestPool runs all pool related tests which require a real database.
 func TestPool(t *testing.T) {
 	// All sub-tests to run. All of these tests will be run with a postgres
@@ -128,6 +140,17 @@ func TestPool(t *testing.T) {
 		boltDB.Close()
 	}
 
+	// Cleanup postgres DB from potential failed previous runs.
+	postgresDB, err := setupPostgresDB()
+	if err != nil {
+		t.Fatalf("setupPostgresDB error: %v", err)
+	}
+	err = postgresDB.purge()
+	if err != nil {
+		t.Fatalf("postgres teardown error: %v", err)
+	}
+	postgresDB.Close()
+
 	// Run all tests with postgres DB.
 	for testName, test := range tests {
 		postgresDB, err := setupPostgresDB()
@@ -139,6 +162,13 @@ func TestPool(t *testing.T) {
 
 		t.Run(testName+"_Postgres", test)
 
+		// Avoid purging the database and running other tests on test failures
+		// when the failfast flag is set.
+		if t.Failed() && isFailFastSet() {
+			postgresDB.Close()
+			break
+		}
+
 		err = postgresDB.purge()
 		if err != nil {
 			t.Fatalf("postgres teardown error: %v", err)