config_test.go

/*
Copyright 2026 The KCP Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package embeddedetcd

import (
	"os"
	"testing"

	"go.etcd.io/etcd/server/v3/storage/wal"

	"github.com/kcp-dev/embeddedetcd/options"
)

func TestUnsafeE2EHackDisableEtcdFsync(t *testing.T) {
	tmpDir := t.TempDir()

	tests := []struct {
		name                 string
		envValue             string
		walSizeBytesOption   int64
		expectUnsafeNoFsync  bool
		expectMaxWalFiles    uint
		expectMaxSnapFiles   uint
		expectWalSegmentSize int64
	}{
		{
			name:                 "env var not set",
			envValue:             "",
			walSizeBytesOption:   0,
			expectUnsafeNoFsync:  false,
			expectMaxWalFiles:    5,                // etcd default
			expectMaxSnapFiles:   5,                // etcd default
			expectWalSegmentSize: 64 * 1024 * 1024, // 64MB default
		},
		{
			name:                 "env var set to false",
			envValue:             "false",
			walSizeBytesOption:   0,
			expectUnsafeNoFsync:  false,
			expectMaxWalFiles:    5,
			expectMaxSnapFiles:   5,
			expectWalSegmentSize: 64 * 1024 * 1024,
		},
		{
			name:                 "env var set to true",
			envValue:             "true",
			walSizeBytesOption:   0,
			expectUnsafeNoFsync:  true,
			expectMaxWalFiles:    1,
			expectMaxSnapFiles:   1,
			expectWalSegmentSize: 1 << 20, // 1MB
		},
		{
			name:                 "env var set to true with custom WAL size",
			envValue:             "true",
			walSizeBytesOption:   2 << 20, // 2MB
			expectUnsafeNoFsync:  true,
			expectMaxWalFiles:    1,
			expectMaxSnapFiles:   1,
			expectWalSegmentSize: 2 << 20, // Should keep custom size
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Set the environment variable
			if tt.envValue != "" {
				os.Setenv("UNSAFE_E2E_HACK_DISABLE_ETCD_FSYNC", tt.envValue)
			} else {
				os.Unsetenv("UNSAFE_E2E_HACK_DISABLE_ETCD_FSYNC")
			}
			defer os.Unsetenv("UNSAFE_E2E_HACK_DISABLE_ETCD_FSYNC")

			// Reset WAL segment size to default before each test
			wal.SegmentSizeBytes = 64 * 1024 * 1024
			walSegmentSet = false

			// Create options
			opts := options.NewOptions(tmpDir)
			opts.WalSizeBytes = tt.walSizeBytesOption
			completedOpts := opts.Complete(nil)

			// Create config
			cfg, err := NewConfig(completedOpts, false)
			if err != nil {
				t.Fatalf("NewConfig failed: %v", err)
			}

			// Verify settings
			if cfg.UnsafeNoFsync != tt.expectUnsafeNoFsync {
				t.Errorf("UnsafeNoFsync: got %v, want %v", cfg.UnsafeNoFsync, tt.expectUnsafeNoFsync)
			}

			if cfg.MaxWalFiles != tt.expectMaxWalFiles {
				t.Errorf("MaxWalFiles: got %v, want %v", cfg.MaxWalFiles, tt.expectMaxWalFiles)
			}

			if cfg.MaxSnapFiles != tt.expectMaxSnapFiles {
				t.Errorf("MaxSnapFiles: got %v, want %v", cfg.MaxSnapFiles, tt.expectMaxSnapFiles)
			}

			if wal.SegmentSizeBytes != tt.expectWalSegmentSize {
				t.Errorf("wal.SegmentSizeBytes: got %v, want %v", wal.SegmentSizeBytes, tt.expectWalSegmentSize)
			}
		})
	}
}

func TestNewConfigRejectsSecondWalSegmentSize(t *testing.T) {
	dir1 := t.TempDir()
	opts1 := options.NewOptions(dir1)
	opts1.WalSizeBytes = 2 << 20
	_, err := NewConfig(opts1.Complete(nil), false)
	if err != nil {
		// The first one failing doesn't matter. It's just to ensure
		// that wal.SegmentSizeBytes was set once.
		t.Logf("first NewConfig failed: %v", err)
	}

	dir2 := t.TempDir()
	opts2 := options.NewOptions(dir2)
	opts2.WalSizeBytes = 3 << 20
	_, err = NewConfig(opts2.Complete(nil), false)
	if err == nil {
		t.Fatal("expected error from second NewConfig with different WalSizeBytes")
	}
}