Add test for PartitionInterval validation

Author: 0xgouda

internal/sinks/postgres_test.go

@@ -499,3 +499,49 @@ func TestCopyFromMeasurements_CopyFail(t *testing.T) {
 	}
 
 }
+
+func TestPartitionIntervalValidation(t *testing.T) {
+	a := assert.New(t)
+	r := require.New(t)
+
+	const ImageName = "docker.io/postgres:17-alpine"
+	pgContainer, err := postgres.Run(ctx,
+		ImageName,
+		postgres.WithDatabase("mydatabase"),
+		testcontainers.WithWaitStrategy(
+			wait.ForLog("database system is ready to accept connections").
+				WithOccurrence(2).
+				WithStartupTimeout(5*time.Second)),
+	)
+	r.NoError(err)
+	defer func() { a.NoError(pgContainer.Terminate(ctx)) }()
+
+	connStr, _ := pgContainer.ConnectionString(ctx, "sslmode=disable")
+
+	a.NoError(err)
+
+	opts := &CmdOpts{
+		PartitionInterval: "1 minute", 
+		Retention: "14 days",
+		BatchingDelay: time.Second,
+	}
+
+	_, err = NewPostgresWriter(ctx, connStr, opts)
+	a.EqualError(err, "Partition interval must be at least 1 hour, got: 1 minute")
+
+	opts.PartitionInterval = "not an interval"
+	_, err = NewPostgresWriter(ctx, connStr, opts)
+	a.Error(err)
+
+	validIntervals := []string{
+		"3 days 4 hours", "1 year",
+		"P3D", "PT3H", "0-02", "1 00:00:00",
+		"P0-02", "P1", "2 weeks",
+	}
+
+	for _, interval := range validIntervals {
+		opts.PartitionInterval = interval
+		_, err = NewPostgresWriter(ctx, connStr, opts)
+		a.NoError( err)
+	}
+}