Add unit tests for state persist interval env var

internal/command/meta_test.go

@@ -219,6 +219,60 @@ func TestMeta_Env(t *testing.T) {
 	}
 }
 
+func TestMeta_StatePersistInterval(t *testing.T) {
+	m := new(Meta)
+	t.Run("when the env var is not defined", func(t *testing.T) {
+		interval := m.StatePersistInterval()
+		if interval != DefaultStatePersistInterval {
+			t.Fatalf("expected state persist interval to be %d, got: %d", DefaultStatePersistInterval, interval)
+		}
+	})
+	t.Run("with valid interval greater than the default", func(t *testing.T) {
+		os.Setenv(StatePersistIntervalEnvVar, "25")
+		t.Cleanup(func() {
+			os.Unsetenv(StatePersistIntervalEnvVar)
+		})
+
+		interval := m.StatePersistInterval()
+		if interval != 25 {
+			t.Fatalf("expected state persist interval to be 25, got: %d", interval)
+		}
+	})
+	t.Run("with a valid interval less than the default", func(t *testing.T) {
+		os.Setenv(StatePersistIntervalEnvVar, "10")
+		t.Cleanup(func() {
+			os.Unsetenv(StatePersistIntervalEnvVar)
+		})
+
+		interval := m.StatePersistInterval()
+		if interval != DefaultStatePersistInterval {
+			t.Fatalf("expected state persist interval to be %d, got: %d", DefaultStatePersistInterval, interval)
+		}
+	})
+	t.Run("with invalid integer interval", func(t *testing.T) {
+		os.Setenv(StatePersistIntervalEnvVar, "foo")
+		t.Cleanup(func() {
+			os.Unsetenv(StatePersistIntervalEnvVar)
+		})
+
+		interval := m.StatePersistInterval()
+		if interval != DefaultStatePersistInterval {
+			t.Fatalf("expected state persist interval to be %d, got: %d", DefaultStatePersistInterval, interval)
+		}
+	})
+	t.Run("with negative integer interval", func(t *testing.T) {
+		os.Setenv(StatePersistIntervalEnvVar, "-10")
+		t.Cleanup(func() {
+			os.Unsetenv(StatePersistIntervalEnvVar)
+		})
+
+		interval := m.StatePersistInterval()
+		if interval != DefaultStatePersistInterval {
+			t.Fatalf("expected state persist interval to be %d, got: %d", DefaultStatePersistInterval, interval)
+		}
+	})
+}
+
 func TestMeta_Workspace_override(t *testing.T) {
 	defer func(value string) {
 		os.Setenv(WorkspaceNameEnvVar, value)