CMD: add test cases for the 'surgery clear-page-elements' command

Signed-off-by: Benjamin Wang <wachao@vmware.com>

cmd/bbolt/command_surgery_cobra_test.go

@@ -0,0 +1,184 @@
+package main_test
+
+import (
+	"fmt"
+	"math/rand"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	bolt "go.etcd.io/bbolt"
+	main "go.etcd.io/bbolt/cmd/bbolt"
+	"go.etcd.io/bbolt/internal/btesting"
+	"go.etcd.io/bbolt/internal/guts_cli"
+)
+
+func TestSurgery_ClearPageElement(t *testing.T) {
+	testCases := []struct {
+		name                 string
+		from                 int
+		to                   int
+		setEndIdxAsCount     bool
+		removeOnlyOneElement bool // only valid when setEndIdxAsCount == true, and startIdx = endIdx -1 in this case.
+		expectError          bool
+	}{
+		// normal range
+		{
+			name: "normal range: [4, 8)",
+			from: 4,
+			to:   8,
+		},
+		{
+			name: "normal range: [5, -1)",
+			from: 4,
+			to:   -1,
+		},
+		{
+			name: "normal range: all",
+			from: 0,
+			to:   -1,
+		},
+		{
+			name: "normal range: [0, 7)",
+			from: 0,
+			to:   7,
+		},
+		{
+			name:             "normal range: [3, count)",
+			from:             4,
+			setEndIdxAsCount: true,
+		},
+		// remove only one element
+		{
+			name: "one element: the first one",
+			from: 0,
+			to:   1,
+		},
+		{
+			name: "one element: [6, 7)",
+			from: 6,
+			to:   7,
+		},
+		{
+			name:                 "one element: the last one",
+			setEndIdxAsCount:     true,
+			removeOnlyOneElement: true,
+		},
+		// abnormal range
+		{
+			name:        "abnormal range: [-1, 4)",
+			from:        -1,
+			to:          4,
+			expectError: true,
+		},
+		{
+			name:        "abnormal range: [-2, 5)",
+			from:        -1,
+			to:          5,
+			expectError: true,
+		},
+		{
+			name:        "abnormal range: [3, 3)",
+			from:        3,
+			to:          3,
+			expectError: true,
+		},
+		{
+			name:        "abnormal range: [5, 3)",
+			from:        5,
+			to:          3,
+			expectError: true,
+		},
+		{
+			name:        "abnormal range: [3, -2)",
+			from:        3,
+			to:          -2,
+			expectError: true,
+		},
+		{
+			name:        "abnormal range: [3, 1000000)",
+			from:        -1,
+			to:          4,
+			expectError: true,
+		},
+	}
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			testSurgeryClearPageElement(t, tc.from, tc.to, tc.setEndIdxAsCount, tc.removeOnlyOneElement, tc.expectError)
+		})
+	}
+}
+
+func testSurgeryClearPageElement(t *testing.T, startIdx, endIdx int, setEndIdxAsCount, removeOnlyOne, expectError bool) {
+	pageSize := 4096
+	db := btesting.MustCreateDBWithOption(t, &bolt.Options{PageSize: pageSize})
+	srcPath := db.Path()
+
+	// Generate sample db
+	t.Log("Generate some sample data")
+	err := db.Fill([]byte("data"), 10, 200,
+		func(tx int, k int) []byte { return []byte(fmt.Sprintf("%04d", tx*10000+k)) },
+		func(tx int, k int) []byte { return make([]byte, 10) },
+	)
+	require.NoError(t, err)
+
+	defer requireDBNoChange(t, dbData(t, srcPath), srcPath)
+
+	// find a page with at least 10 elements
+	var (
+		pageId       uint64 = 2
+		elementCount uint16 = 0
+	)
+	for {
+		p, _, err := guts_cli.ReadPage(srcPath, pageId)
+		require.NoError(t, err)
+
+		if p.IsLeafPage() && p.Count() > 10 {
+			elementCount = p.Count()
+			break
+		}
+		pageId++
+	}
+	t.Logf("The original element count: %d", elementCount)
+
+	if setEndIdxAsCount {
+		t.Logf("Set the endIdx as the element count: %d", elementCount)
+		endIdx = int(elementCount)
+		if removeOnlyOne {
+			startIdx = endIdx - 1
+			t.Logf("Set the startIdx as the endIdx-1: %d", startIdx)
+		}
+	}
+
+	// clear elements [startIdx, endIdx) in the page
+	rootCmd := main.NewRootCommand()
+	output := filepath.Join(t.TempDir(), fmt.Sprintf("db_%d", rand.Intn(100)))
+	rootCmd.SetArgs([]string{
+		"surgery", "clear-page-elements", srcPath,
+		"--output", output,
+		"--pageId", fmt.Sprintf("%d", pageId),
+		"--from", fmt.Sprintf("%d", startIdx),
+		"--to", fmt.Sprintf("%d", endIdx),
+	})
+	err = rootCmd.Execute()
+	if expectError {
+		require.Error(t, err)
+		return
+	}
+
+	require.NoError(t, err)
+
+	// check the element count again
+	expectedCnt := 0
+	if endIdx == -1 {
+		expectedCnt = startIdx
+	} else {
+		expectedCnt = int(elementCount) - (endIdx - startIdx)
+	}
+	p, _, err := guts_cli.ReadPage(output, pageId)
+	require.NoError(t, err)
+	assert.Equal(t, expectedCnt, int(p.Count()))
+}