Pull request 2109: AG-20945-rule-list-filter

Squashed commit of the following:

commit 2da8c1754f349a9b7f8b629de8f0c892b9bae4dc
Merge: 5cea6a6a2 4fc6bf504
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 19 21:14:07 2023 +0300

    Merge branch 'master' into AG-20945-rule-list-filter

commit 5cea6a6a2bed88f645828ab5b4e7de09f9bf91ec
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 19 17:53:21 2023 +0300

    filtering/rulelist: imp docs, tests

commit f01434b37a3f0070d71eb0ae72ad8eb2f4922147
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 14 19:17:02 2023 +0300

    filtering/rulelist: imp names

commit fe2bf68e6b99673b216b5c4ba867a5f4ed788d22
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 14 19:07:53 2023 +0300

    all: go mod tidy

commit c7081d3486a78e8402dc8fe0223111a6fccdd19f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 14 19:03:33 2023 +0300

    filtering/rulelist: add filter

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/NYTimes/gziphandler v1.1.1
 	github.com/ameshkov/dnscrypt/v2 v2.2.7
 	github.com/bluele/gcache v0.0.2
+	github.com/c2h5oh/datasize v0.0.0-20220606134207-859f65c6625b
 	github.com/digineo/go-ipset/v2 v2.2.1
 	github.com/dimfeld/httptreemux/v5 v5.5.0
 	github.com/fsnotify/fsnotify v1.7.0
@@ -16,7 +17,7 @@ require (
 	github.com/google/go-cmp v0.6.0
 	github.com/google/gopacket v1.1.19
 	github.com/google/renameio/v2 v2.0.0
-	github.com/google/uuid v1.4.0
+	github.com/google/uuid v1.5.0
 	github.com/insomniacslk/dhcp v0.0.0-20231206064809-8c70d406f6d2
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86
 	github.com/kardianos/service v1.2.2

go.sum

@@ -18,6 +18,8 @@ github.com/beefsack/go-rate v0.0.0-20220214233405-116f4ca011a0 h1:0b2vaepXIfMsG+
 github.com/beefsack/go-rate v0.0.0-20220214233405-116f4ca011a0/go.mod h1:6YNgTHLutezwnBvyneBbwvB8C82y3dcoOj5EQJIdGXA=
 github.com/bluele/gcache v0.0.2 h1:WcbfdXICg7G/DGBh1PFfcirkWOQV+v077yF1pSy3DGw=
 github.com/bluele/gcache v0.0.2/go.mod h1:m15KV+ECjptwSPxKhOhQoAFQVtUFjTVkc3H8o0t/fp0=
+github.com/c2h5oh/datasize v0.0.0-20220606134207-859f65c6625b h1:6+ZFm0flnudZzdSE0JxlhR2hKnGPcNB35BjQf4RYQDY=
+github.com/c2h5oh/datasize v0.0.0-20220606134207-859f65c6625b/go.mod h1:S/7n9copUssQ56c7aAgHqftWO4LTf4xY6CGWt8Bc+3M=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -46,8 +48,8 @@ github.com/google/pprof v0.0.0-20231205033806-a5a03c77bf08/go.mod h1:czg5+yv1E0Z
 github.com/google/renameio/v2 v2.0.0 h1:UifI23ZTGY8Tt29JbYFiuyIU3eX+RNFtUwefq9qAhxg=
 github.com/google/renameio/v2 v2.0.0/go.mod h1:BtmJXm5YlszgC+TD4HOEEUFgkJP3nLxehU6hfe7jRt4=
 github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/google/uuid v1.4.0 h1:MtMxsa51/r9yyhkyLsVeVt0B+BGQZzpQiTQ4eHZ8bc4=
+github.com/google/uuid v1.5.0 h1:1p67kYwdtXjb0gL0BPiP1Av9wiZPo5A8z2cWkTZ+eyU=
-github.com/google/uuid v1.4.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/google/uuid v1.5.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714 h1:/jC7qQFrv8CrSJVmaolDVOxTfS9kc36uB6H40kdbQq8=
 github.com/insomniacslk/dhcp v0.0.0-20231206064809-8c70d406f6d2 h1:9K06NfxkBh25x56yVhWWlKFE8YpicaSfHwoV8SFbueA=
 github.com/insomniacslk/dhcp v0.0.0-20231206064809-8c70d406f6d2/go.mod h1:3A9PQ1cunSDF/1rbTq99Ts4pVnycWg+vlPkfeD2NLFI=

internal/filtering/http.go

@@ -24,23 +24,25 @@ func validateFilterURL(urlStr string) (err error) {
 
 	if filepath.IsAbs(urlStr) {
 		_, err = os.Stat(urlStr)
-		if err != nil {
+
 		// Don't wrap the error since it's informative enough as is.
 		return err
 	}
 
-		return nil
-	}
-
 	u, err := url.ParseRequestURI(urlStr)
 	if err != nil {
 		// Don't wrap the error since it's informative enough as is.
 		return err
-	} else if s := u.Scheme; s != aghhttp.SchemeHTTP && s != aghhttp.SchemeHTTPS {
+	}
+
+	if s := u.Scheme; s != aghhttp.SchemeHTTP && s != aghhttp.SchemeHTTPS {
 		return &url.Error{
 			Op:  "Check scheme",
 			URL: urlStr,
-			Err: fmt.Errorf("only %v allowed", []string{aghhttp.SchemeHTTP, aghhttp.SchemeHTTPS}),
+			Err: fmt.Errorf("only %v allowed", []string{
+				aghhttp.SchemeHTTP,
+				aghhttp.SchemeHTTPS,
+			}),
 		}
 	}
 

internal/filtering/rulelist/filter.go

@@ -0,0 +1,338 @@
+package rulelist
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghrenameio"
+	"github.com/AdguardTeam/golibs/errors"
+	"github.com/AdguardTeam/golibs/ioutil"
+	"github.com/AdguardTeam/golibs/log"
+	"github.com/AdguardTeam/urlfilter/filterlist"
+	"github.com/c2h5oh/datasize"
+)
+
+// Filter contains information about a single rule-list filter.
+//
+// TODO(a.garipov): Use.
+type Filter struct {
+	// url is the URL of this rule list.  Supported schemes are:
+	//   - http
+	//   - https
+	//   - file
+	url *url.URL
+
+	// ruleList is the last successfully compiled [filterlist.RuleList].
+	ruleList filterlist.RuleList
+
+	// updated is the time of the last successful update.
+	updated time.Time
+
+	// name is the human-readable name of this rule-list filter.
+	name string
+
+	// uid is the unique ID of this rule-list filter.
+	uid UID
+
+	// urlFilterID is used for working with package urlfilter.
+	urlFilterID URLFilterID
+
+	// rulesCount contains the number of rules in this rule-list filter.
+	rulesCount int
+
+	// checksum is a CRC32 hash used to quickly check if the rules within a list
+	// file have changed.
+	checksum uint32
+
+	// enabled, if true, means that this rule-list filter is used for filtering.
+	//
+	// TODO(a.garipov): Take into account.
+	enabled bool
+}
+
+// FilterConfig contains the configuration for a [Filter].
+type FilterConfig struct {
+	// URL is the URL of this rule-list filter.  Supported schemes are:
+	//   - http
+	//   - https
+	//   - file
+	URL *url.URL
+
+	// Name is the human-readable name of this rule-list filter.  If not set, it
+	// is either taken from the rule-list data or generated synthetically from
+	// the UID.
+	Name string
+
+	// UID is the unique ID of this rule-list filter.
+	UID UID
+
+	// URLFilterID is used for working with package urlfilter.
+	URLFilterID URLFilterID
+
+	// Enabled, if true, means that this rule-list filter is used for filtering.
+	Enabled bool
+}
+
+// NewFilter creates a new rule-list filter.  The filter is not refreshed, so a
+// refresh should be performed before use.
+func NewFilter(c *FilterConfig) (f *Filter, err error) {
+	if c.URL == nil {
+		return nil, errors.Error("no url")
+	}
+
+	switch s := c.URL.Scheme; s {
+	case "http", "https", "file":
+		// Go on.
+	default:
+		return nil, fmt.Errorf("bad url scheme: %q", s)
+	}
+
+	return &Filter{
+		url:         c.URL,
+		name:        c.Name,
+		uid:         c.UID,
+		urlFilterID: c.URLFilterID,
+		enabled:     c.Enabled,
+	}, nil
+}
+
+// Refresh updates the data in the rule-list filter.  parseBuf is the initial
+// buffer used to parse information from the data.  cli and maxSize are only
+// used when f is a URL-based list.
+func (f *Filter) Refresh(
+	ctx context.Context,
+	parseBuf []byte,
+	cli *http.Client,
+	cacheDir string,
+	maxSize datasize.ByteSize,
+) (parseRes *ParseResult, err error) {
+	cachePath := filepath.Join(cacheDir, f.uid.String()+".txt")
+
+	switch s := f.url.Scheme; s {
+	case "http", "https":
+		parseRes, err = f.setFromHTTP(ctx, parseBuf, cli, cachePath, maxSize.Bytes())
+	case "file":
+		parseRes, err = f.setFromFile(parseBuf, f.url.Path, cachePath)
+	default:
+		// Since the URL has been prevalidated in New, consider this a
+		// programmer error.
+		panic(fmt.Errorf("bad url scheme: %q", s))
+	}
+	if err != nil {
+		// Don't wrap the error, because it's informative enough as is.
+		return nil, err
+	}
+
+	if f.checksum != parseRes.Checksum {
+		f.checksum = parseRes.Checksum
+		f.rulesCount = parseRes.RulesCount
+		f.setName(parseRes.Title)
+		f.updated = time.Now()
+	}
+
+	return parseRes, nil
+}
+
+// setFromHTTP sets the rule-list filter's data from its URL.  It also caches
+// the data into a file.
+func (f *Filter) setFromHTTP(
+	ctx context.Context,
+	parseBuf []byte,
+	cli *http.Client,
+	cachePath string,
+	maxSize uint64,
+) (parseRes *ParseResult, err error) {
+	defer func() { err = errors.Annotate(err, "setting from http: %w") }()
+
+	text, parseRes, err := f.readFromHTTP(ctx, parseBuf, cli, cachePath, maxSize)
+	if err != nil {
+		// Don't wrap the error, because it's informative enough as is.
+		return nil, err
+	}
+
+	// TODO(a.garipov): Add filterlist.BytesRuleList.
+	f.ruleList = &filterlist.StringRuleList{
+		ID:             f.urlFilterID,
+		RulesText:      text,
+		IgnoreCosmetic: true,
+	}
+
+	return parseRes, nil
+}
+
+// readFromHTTP reads the data from the rule-list filter's URL into the cache
+// file as well as returns it as a string.  The data is filtered through a
+// parser and so is free from comments, unnecessary whitespace, etc.
+func (f *Filter) readFromHTTP(
+	ctx context.Context,
+	parseBuf []byte,
+	cli *http.Client,
+	cachePath string,
+	maxSize uint64,
+) (text string, parseRes *ParseResult, err error) {
+	urlStr := f.url.String()
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, urlStr, nil)
+	if err != nil {
+		return "", nil, fmt.Errorf("making request for http url %q: %w", urlStr, err)
+	}
+
+	resp, err := cli.Do(req)
+	if err != nil {
+		return "", nil, fmt.Errorf("requesting from http url: %w", err)
+	}
+	defer func() { err = errors.WithDeferred(err, resp.Body.Close()) }()
+
+	// TODO(a.garipov): Use [agdhttp.CheckStatus] when it's moved to golibs.
+	if resp.StatusCode != http.StatusOK {
+		return "", nil, fmt.Errorf("got status code %d, want %d", resp.StatusCode, http.StatusOK)
+	}
+
+	fltFile, err := aghrenameio.NewPendingFile(cachePath, 0o644)
+	if err != nil {
+		return "", nil, fmt.Errorf("creating temp file: %w", err)
+	}
+	defer func() { err = aghrenameio.WithDeferredCleanup(err, fltFile) }()
+
+	buf := &bytes.Buffer{}
+	mw := io.MultiWriter(buf, fltFile)
+
+	parser := NewParser()
+	httpBody := ioutil.LimitReader(resp.Body, maxSize)
+	parseRes, err = parser.Parse(mw, httpBody, parseBuf)
+	if err != nil {
+		return "", nil, fmt.Errorf("parsing response from http url %q: %w", urlStr, err)
+	}
+
+	return buf.String(), parseRes, nil
+}
+
+// setName sets the title using either the already-present name, the given title
+// from the rule-list data, or a synthetic name.
+func (f *Filter) setName(title string) {
+	if f.name != "" {
+		return
+	}
+
+	if title != "" {
+		f.name = title
+
+		return
+	}
+
+	f.name = fmt.Sprintf("List %s", f.uid)
+}
+
+// setFromFile sets the rule-list filter's data from a file path.  It also
+// caches the data into a file.
+//
+// TODO(a.garipov): Retest on Windows once rule-list updater is committed.  See
+// if calling Close is necessary here.
+func (f *Filter) setFromFile(
+	parseBuf []byte,
+	filePath string,
+	cachePath string,
+) (parseRes *ParseResult, err error) {
+	defer func() { err = errors.Annotate(err, "setting from file: %w") }()
+
+	parseRes, err = parseIntoCache(parseBuf, filePath, cachePath)
+	if err != nil {
+		// Don't wrap the error, because it's informative enough as is.
+		return nil, err
+	}
+
+	err = f.Close()
+	if err != nil {
+		return nil, fmt.Errorf("closing old rule list: %w", err)
+	}
+
+	rl, err := filterlist.NewFileRuleList(f.urlFilterID, cachePath, true)
+	if err != nil {
+		return nil, fmt.Errorf("opening new rule list: %w", err)
+	}
+
+	f.ruleList = rl
+
+	return parseRes, nil
+}
+
+// parseIntoCache copies the relevant the data from filePath into cachePath
+// while also parsing it.
+func parseIntoCache(
+	parseBuf []byte,
+	filePath string,
+	cachePath string,
+) (parseRes *ParseResult, err error) {
+	tmpFile, err := aghrenameio.NewPendingFile(cachePath, 0o644)
+	if err != nil {
+		return nil, fmt.Errorf("creating temp file: %w", err)
+	}
+	defer func() { err = aghrenameio.WithDeferredCleanup(err, tmpFile) }()
+
+	// #nosec G304 -- Assume that cachePath is always cacheDir joined with a
+	// uid using [filepath.Join].
+	f, err := os.Open(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("opening src file: %w", err)
+	}
+	defer func() { err = errors.WithDeferred(err, f.Close()) }()
+
+	parser := NewParser()
+	parseRes, err = parser.Parse(tmpFile, f, parseBuf)
+	if err != nil {
+		return nil, fmt.Errorf("copying src file: %w", err)
+	}
+
+	return parseRes, nil
+}
+
+// Close closes the underlying rule list.
+func (f *Filter) Close() (err error) {
+	if f.ruleList == nil {
+		return nil
+	}
+
+	return f.ruleList.Close()
+}
+
+// filterUpdate represents a single ongoing rule-list filter update.
+//
+//lint:ignore U1000 TODO(a.garipov): Use.
+type filterUpdate struct {
+	httpCli  *http.Client
+	cacheDir string
+	name     string
+	parseBuf []byte
+	maxSize  datasize.ByteSize
+}
+
+// process runs an update of a single rule-list.
+func (u *filterUpdate) process(ctx context.Context, f *Filter) (err error) {
+	prevChecksum := f.checksum
+	parseRes, err := f.Refresh(ctx, u.parseBuf, u.httpCli, u.cacheDir, u.maxSize)
+	if err != nil {
+		return fmt.Errorf("updating %s: %w", f.uid, err)
+	}
+
+	if prevChecksum == parseRes.Checksum {
+		log.Info("filtering: filter %q: filter %q: no change", u.name, f.uid)
+
+		return nil
+	}
+
+	log.Info(
+		"filtering: updated filter %q: filter %q: %d bytes, %d rules",
+		u.name,
+		f.uid,
+		parseRes.BytesWritten,
+		parseRes.RulesCount,
+	)
+
+	return nil
+}

internal/filtering/rulelist/filter_test.go

@@ -0,0 +1,107 @@
+package rulelist_test
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
+	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFilter_Refresh(t *testing.T) {
+	cacheDir := t.TempDir()
+	uid := rulelist.MustNewUID()
+
+	initialFile := filepath.Join(cacheDir, "initial.txt")
+	initialData := []byte(
+		testRuleTextTitle +
+			testRuleTextBlocked,
+	)
+	writeErr := os.WriteFile(initialFile, initialData, 0o644)
+	require.NoError(t, writeErr)
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		pt := testutil.PanicT{}
+
+		_, err := io.WriteString(w, testRuleTextTitle+testRuleTextBlocked)
+		require.NoError(pt, err)
+	}))
+
+	srvURL, urlErr := url.Parse(srv.URL)
+	require.NoError(t, urlErr)
+
+	testCases := []struct {
+		url           *url.URL
+		name          string
+		wantNewErrMsg string
+	}{{
+		url:           nil,
+		name:          "nil_url",
+		wantNewErrMsg: "no url",
+	}, {
+		url: &url.URL{
+			Scheme: "ftp",
+		},
+		name:          "bad_scheme",
+		wantNewErrMsg: `bad url scheme: "ftp"`,
+	}, {
+		name: "file",
+		url: &url.URL{
+			Scheme: "file",
+			Path:   initialFile,
+		},
+		wantNewErrMsg: "",
+	}, {
+		name:          "http",
+		url:           srvURL,
+		wantNewErrMsg: "",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			f, err := rulelist.NewFilter(&rulelist.FilterConfig{
+				URL:         tc.url,
+				Name:        tc.name,
+				UID:         uid,
+				URLFilterID: testURLFilterID,
+				Enabled:     true,
+			})
+			if tc.wantNewErrMsg != "" {
+				assert.EqualError(t, err, tc.wantNewErrMsg)
+
+				return
+			}
+
+			testutil.CleanupAndRequireSuccess(t, f.Close)
+
+			require.NotNil(t, f)
+
+			ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
+			t.Cleanup(cancel)
+
+			buf := make([]byte, rulelist.DefaultRuleBufSize)
+			cli := &http.Client{
+				Timeout: testTimeout,
+			}
+
+			res, err := f.Refresh(ctx, buf, cli, cacheDir, rulelist.DefaultMaxRuleListSize)
+			require.NoError(t, err)
+
+			assert.Equal(t, testTitle, res.Title)
+			assert.Equal(t, len(testRuleTextBlocked), res.BytesWritten)
+			assert.Equal(t, 1, res.RulesCount)
+
+			// Check that the cached file exists.
+			_, err = os.Stat(filepath.Join(cacheDir, uid.String()+".txt"))
+			require.NoError(t, err)
+		})
+	}
+}

internal/filtering/rulelist/parser_test.go

@@ -69,12 +69,12 @@ func TestParser_Parse(t *testing.T) {
 		wantWritten:  len(testRuleTextBlocked) + len(testRuleTextHTML),
 	}, {
 		name: "title",
-		in: "! Title:  Test Title \n" +
+		in: testRuleTextTitle +
 			"! Title: Bad, Ignored Title\n" +
 			testRuleTextBlocked,
 		wantDst:      testRuleTextBlocked,
 		wantErrMsg:   "",
-		wantTitle:    "Test Title",
+		wantTitle:    testTitle,
 		wantRulesNum: 1,
 		wantWritten:  len(testRuleTextBlocked),
 	}, {
@@ -87,14 +87,14 @@ func TestParser_Parse(t *testing.T) {
 		wantWritten:  len(testRuleTextCosmetic),
 	}, {
 		name: "bad_char",
-		in: "! Title:  Test Title \n" +
+		in: testRuleTextTitle +
 			testRuleTextBlocked +
 			">>>\x7F<<<",
 		wantDst: testRuleTextBlocked,
 		wantErrMsg: "line 3: " +
 			"character 4: " +
 			"likely binary character '\\x7f'",
-		wantTitle:    "Test Title",
+		wantTitle:    testTitle,
 		wantRulesNum: 1,
 		wantWritten:  len(testRuleTextBlocked),
 	}, {

internal/filtering/rulelist/rulelist.go

@@ -1,9 +1,55 @@
 // Package rulelist contains the implementation of the standard rule-list
 // filter that wraps an urlfilter filtering-engine.
 //
-// TODO(a.garipov): Expand.
+// TODO(a.garipov): Add a new update worker.
 package rulelist
 
+import (
+	"fmt"
+
+	"github.com/c2h5oh/datasize"
+	"github.com/google/uuid"
+)
+
 // DefaultRuleBufSize is the default length of a buffer used to read a line with
 // a filtering rule, in bytes.
+//
+// TODO(a.garipov): Consider using [datasize.ByteSize].  It is currently only
+// used as an int.
 const DefaultRuleBufSize = 1024
+
+// DefaultMaxRuleListSize is the default maximum filtering-rule list size.
+const DefaultMaxRuleListSize = 64 * datasize.MB
+
+// URLFilterID is a semantic type-alias for IDs used for working with package
+// urlfilter.
+type URLFilterID = int
+
+// UID is the type for the unique IDs of filtering-rule lists.
+type UID uuid.UUID
+
+// NewUID returns a new filtering-rule list UID.  Any error returned is an error
+// from the cryptographic randomness reader.
+func NewUID() (uid UID, err error) {
+	uuidv7, err := uuid.NewV7()
+
+	return UID(uuidv7), err
+}
+
+// MustNewUID is a wrapper around [NewUID] that panics if there is an error.
+func MustNewUID() (uid UID) {
+	uid, err := NewUID()
+	if err != nil {
+		panic(fmt.Errorf("unexpected uuidv7 error: %w", err))
+	}
+
+	return uid
+}
+
+// type check
+var _ fmt.Stringer = UID{}
+
+// String implements the [fmt.Stringer] interface for UID.
+func (id UID) String() (s string) {
+	return uuid.UUID(id).String()
+}

internal/filtering/rulelist/rulelist_test.go

@@ -1,16 +1,34 @@
 package rulelist_test
 
-import "time"
+import (
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
+	"github.com/AdguardTeam/golibs/testutil"
+)
+
+func TestMain(m *testing.M) {
+	testutil.DiscardLogOutput(m)
+}
 
 // testTimeout is the common timeout for tests.
 const testTimeout = 1 * time.Second
 
-// Common texts for tests.
+// testURLFilterID is the common [rulelist.URLFilterID] for tests.
+const testURLFilterID rulelist.URLFilterID = 1
+
+// testTitle is the common title for tests.
+const testTitle = "Test Title"
+
+// Common rule texts for tests.
 const (
 	testRuleTextBadTab      = "||bad-tab-and-comment.example^\t# A comment.\n"
 	testRuleTextBlocked     = "||blocked.example^\n"
+	testRuleTextBlocked2    = "||blocked-2.example^\n"
 	testRuleTextEtcHostsTab = "0.0.0.0 tab..example^\t# A comment.\n"
 	testRuleTextHTML        = "<!DOCTYPE html>\n"
+	testRuleTextTitle       = "! Title:  " + testTitle + " \n"
 
 	// testRuleTextCosmetic is a cosmetic rule with a zero-width non-joiner.
 	//