Artifact [2be756e4da]

Artifact 2be756e4dab08e3ad531f564f1a62b411ebbbdb1f1d64f113d29a19194029858:

• File internal/sync/sync_test.go — part of check-in [821cf115ce] at 2026-10-12 22:48:22 on branch main — fix(sync): refuse push and pull cards naming another project (#309) (#353)

  fossil's page_xfer compares a push or pull card's PROJECTCODE with the repository's project-code before any capability check and, on a mismatch, resets the reply, answers "error wrong project" and breaks out of the card loop (section 8.5). The handler accepted either card whatever its project code.

  The refusal goes through a new breakLoop, which the undecodable file card path now shares: the reply is reset to the one error, no later card is processed, and the post-loop work and timestamp still follow. Tests that synced repositories created with different project codes now create them with a shared one, and the DST simulator gives its leaves the upstream's. (user: [email protected], size: 22918) [annotate] [blame] [check-ins using]

package sync

import (
	"bytes"
	"context"
	"crypto/sha1"
	"encoding/hex"
	"fmt"
	"path/filepath"
	"strings"
	"testing"

	"github.com/danmestas/go-libfossil/internal/auth"
	"github.com/danmestas/go-libfossil/internal/blob"
	"github.com/danmestas/go-libfossil/internal/content"
	"github.com/danmestas/go-libfossil/internal/delta"
	"github.com/danmestas/go-libfossil/internal/hash"
	"github.com/danmestas/go-libfossil/internal/repo"
	_ "github.com/danmestas/go-libfossil/internal/testdriver"
	"github.com/danmestas/go-libfossil/internal/xfer"
	"github.com/danmestas/go-libfossil/simio"
)

func TestMockTransportExchange(t *testing.T) {
	mt := &MockTransport{
		Handler: func(req *xfer.Message) *xfer.Message {
			return &xfer.Message{Cards: []xfer.Card{
				&xfer.IGotCard{UUID: "response-uuid"},
			}}
		},
	}
	resp, err := mt.Exchange(context.Background(), &xfer.Message{})
	if err != nil {
		t.Fatalf("Exchange: %v", err)
	}
	if len(resp.Cards) != 1 {
		t.Fatalf("cards = %d, want 1", len(resp.Cards))
	}
}

func TestMockTransportNilHandler(t *testing.T) {
	mt := &MockTransport{}
	resp, err := mt.Exchange(context.Background(), &xfer.Message{})
	if err != nil {
		t.Fatalf("Exchange: %v", err)
	}
	if len(resp.Cards) != 0 {
		t.Fatalf("expected empty response")
	}
}

func sha1hex(data string) string {
	h := sha1.Sum([]byte(data))
	return hex.EncodeToString(h[:])
}

func TestComputeLogin(t *testing.T) {
	payload := []byte("pull abc def\nigot da39a3ee5e6b4b0d3255bfef95601890afd80709\n")
	card := computeLogin("testuser", "secret", "projcode", payload)
	if card.User != "testuser" {
		t.Fatalf("User = %q", card.User)
	}
	expectedNonce := sha1hex(string(payload))
	if card.Nonce != expectedNonce {
		t.Fatalf("Nonce = %q, want %q", card.Nonce, expectedNonce)
	}
	secret := sha1hex("projcode/testuser/secret")
	expectedSig := sha1hex(card.Nonce + secret)
	if card.Signature != expectedSig {
		t.Fatalf("Signature = %q, want %q", card.Signature, expectedSig)
	}
}

// TestComputeLoginMatchesCapturedFossilCard replays a login card fossil 2.28
// actually put on the wire and requires us to reproduce it byte for byte.
//
// The payload is the request body that followed that login card, captured with
// `fossil clone --httptrace` against a server whose project code and user
// password are the constants below. Two things about it are load-bearing and
// were both wrong before #203: the trailing "# ..." comment is part of the
// hashed payload and so must be transmitted, not merely hashed; and the
// signature covers the *hashed* password, salted with the project code.
func TestComputeLoginMatchesCapturedFossilCard(t *testing.T) {
	const (
		projectCode = "2d5573080bf03f15ed58105794cc80c6a51f4c52"
		user        = "syncer"
		password    = "pw123"
		wantNonce   = "0a1023892bbe47501cfd1e1a54fd0bc1e403eed7"
		wantSig     = "7e93a6c9f1a38d9a00f08b74248adf6a6b86497a"
	)
	payload := []byte("pragma client-version 22800 20260311 113146\n" +
		"clone 3 1\n" +
		"reqconfig /all\n" +
		"# EAFD8046BFE8B4CF96EC2C919144A9B13DC026BB\n")

	card := computeLogin(user, password, projectCode, payload)
	if card.Nonce != wantNonce {
		t.Errorf("Nonce = %q, want %q (fossil's own card for this payload)", card.Nonce, wantNonce)
	}
	if card.Signature != wantSig {
		t.Errorf("Signature = %q, want %q (fossil's own card for these credentials)", card.Signature, wantSig)
	}
}

// TestLoginNonceCoversTheTransmittedBody is the §6.2 conformance test: the
// nonce is "SHA-1 over every decompressed body byte after the body login
// line's LF through body end". It recomputes the nonce from the message the
// client is actually about to send, rather than from whatever the client chose
// to hash.
//
// That distinction is the #203 defect. The random comment supplying the nonce
// its uniqueness was appended to the hashed payload but never added to the
// message, so the covered range and the transmitted range differed by one
// line. The server, which recomputes the nonce from the bytes it received,
// rejected every login before comparing a password — making a correct password
// indistinguishable from a wrong one.
func TestLoginNonceCoversTheTransmittedBody(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, User: "syncer", Password: "pw123"})

	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	login, ok := msg.Cards[0].(*xfer.LoginCard)
	if !ok {
		t.Fatalf("first card is %T, want *xfer.LoginCard — the login card leads the body", msg.Cards[0])
	}

	body, err := encodeCards(msg.Cards)
	if err != nil {
		t.Fatalf("encodeCards: %v", err)
	}
	lf := bytes.IndexByte(body, '\n')
	if lf < 0 {
		t.Fatal("encoded body has no LF")
	}
	tail := body[lf+1:]

	if got := sha1hex(string(tail)); got != login.Nonce {
		t.Errorf("nonce = %q, but SHA-1 of the body after the login line's LF is %q;\n"+
			"the client signed bytes it is not sending:\n%s", login.Nonce, got, tail)
	}

	// The tail must end with the nonce comment — that is where the randomness
	// lives, and it only varies the nonce if it is actually transmitted.
	if !bytes.HasSuffix(tail, []byte("\n")) || !bytes.Contains(tail, []byte("\n# ")) {
		t.Errorf("body after the login line carries no nonce comment:\n%s", tail)
	}
}

func TestComputeLoginAnonymous(t *testing.T) {
	card := computeLogin("anonymous", "", "projcode", []byte("test\n"))
	if card.User != "anonymous" {
		t.Fatalf("User = %q", card.User)
	}
	if card.Nonce == "" {
		t.Fatal("anonymous should still have nonce")
	}
}

func TestRandomComment(t *testing.T) {
	rng := simio.CryptoRand{}
	if randomComment(rng).Text == randomComment(rng).Text {
		t.Fatal("random comments should be unique")
	}

	// The comment is what makes each nonce unique, so it has to reach the
	// wire — a login card the server can validate hashes bytes it received.
	var buf bytes.Buffer
	if err := xfer.EncodeCard(&buf, randomComment(rng)); err != nil {
		t.Fatalf("EncodeCard: %v", err)
	}
	line := buf.String()
	if !strings.HasPrefix(line, "# ") || !strings.HasSuffix(line, "\n") {
		t.Fatalf("comment encoded as %q, want a \"# ...\\n\" line", line)
	}
}

// --- Test helpers ---

// testPC is the project code test repositories are created with. A server
// refuses a push or pull card naming another project (§8.5), so the
// repositories a test syncs share it, as a clone shares its origin's.
const testPC = "77dc1a9065e8b8ff0d35abe4e26498cdf9576d6a"

func setupSyncTestRepo(t *testing.T) *repo.Repo {
	t.Helper()
	path := filepath.Join(t.TempDir(), "test.fossil")
	r, err := repo.Create(path, "testuser", simio.CryptoRand{}, testPC)
	if err != nil {
		t.Fatalf("repo.Create: %v", err)
	}
	t.Cleanup(func() { r.Close() })
	return r
}

// grantNobodyPush lets unauthenticated clients push artifacts (i) and
// unversioned files (y) to r. A new repository grants nobody only fossil's
// "gjorz", so a test that pushes without a login card has to grant this.
func grantNobodyPush(t *testing.T, r *repo.Repo) {
	t.Helper()
	if err := auth.UpdateCaps(r.DB(), "nobody", "gijoryz"); err != nil {
		t.Fatalf("grant nobody push: %v", err)
	}
}

// setupPushableTestRepo is setupSyncTestRepo for a server that accepts
// unauthenticated pushes.
func setupPushableTestRepo(t *testing.T) *repo.Repo {
	t.Helper()
	r := setupSyncTestRepo(t)
	grantNobodyPush(t, r)
	return r
}

func newTestSession(t *testing.T, opts SyncOpts) (*session, *repo.Repo) {
	t.Helper()
	r := setupSyncTestRepo(t)
	return newSession(r, opts), r
}

// --- buildRequest tests ---

func TestBuildRequestPushOnly(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{
		Push:        true,
		Pull:        false,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	pushCards := cardsByType(msg, xfer.CardPush)
	pullCards := cardsByType(msg, xfer.CardPull)
	if len(pushCards) != 1 {
		t.Fatalf("push cards = %d, want 1", len(pushCards))
	}
	if len(pullCards) != 0 {
		t.Fatalf("pull cards = %d, want 0", len(pullCards))
	}
}

func TestBuildRequestPullOnly(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{
		Push:        false,
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	pushCards := cardsByType(msg, xfer.CardPush)
	pullCards := cardsByType(msg, xfer.CardPull)
	if len(pushCards) != 0 {
		t.Fatalf("push cards = %d, want 0", len(pushCards))
	}
	if len(pullCards) != 1 {
		t.Fatalf("pull cards = %d, want 1", len(pullCards))
	}
}

func TestBuildRequestHasPragmaClientVersion(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})
	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	pragmas := cardsByType(msg, xfer.CardPragma)
	if len(pragmas) == 0 {
		t.Fatal("no pragma cards found")
	}
	p := pragmas[0].(*xfer.PragmaCard)
	if p.Name != "client-version" {
		t.Fatalf("pragma name = %q, want client-version", p.Name)
	}
}

func TestBuildRequestIGotFromUnclustered(t *testing.T) {
	s, r := newTestSession(t, SyncOpts{Push: true, ServerCode: "sc", ProjectCode: testPC})

	// Store a blob — blob.Store auto-marks unclustered.
	content := []byte("test artifact for igot")
	_, uuid, err := blob.Store(r.DB(), content)
	if err != nil {
		t.Fatalf("blob.Store: %v", err)
	}

	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	igots := cardsByType(msg, xfer.CardIGot)
	if len(igots) == 0 {
		t.Fatal("expected igot cards from unclustered")
	}
	found := false
	for _, c := range igots {
		if c.(*xfer.IGotCard).UUID == uuid {
			found = true
		}
	}
	if !found {
		t.Fatalf("igot card for uuid %s not found", uuid)
	}
}

func TestBuildRequestGimmeForPhantoms(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	phantomUUID := "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
	s.phantoms[phantomUUID] = true

	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	gimmes := cardsByType(msg, xfer.CardGimme)
	if len(gimmes) != 1 {
		t.Fatalf("gimme cards = %d, want 1", len(gimmes))
	}
	if gimmes[0].(*xfer.GimmeCard).UUID != phantomUUID {
		t.Fatalf("gimme uuid = %q, want %q", gimmes[0].(*xfer.GimmeCard).UUID, phantomUUID)
	}
}

func TestBuildRequestFileForPendingSend(t *testing.T) {
	s, r := newTestSession(t, SyncOpts{Push: true, ServerCode: "sc", ProjectCode: testPC})

	// Store a blob and add its UUID to pendingSend
	content := []byte("file to send over sync")
	_, uuid, err := blob.Store(r.DB(), content)
	if err != nil {
		t.Fatalf("blob.Store: %v", err)
	}
	s.pendingSend[uuid] = true

	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	files := cardsByType(msg, xfer.CardFile)
	if len(files) != 1 {
		t.Fatalf("file cards = %d, want 1", len(files))
	}
	fc := files[0].(*xfer.FileCard)
	if fc.UUID != uuid {
		t.Fatalf("file uuid = %q, want %q", fc.UUID, uuid)
	}
	if string(fc.Content) != string(content) {
		t.Fatalf("file content mismatch")
	}
}

func TestBuildRequestWithLogin(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
		User:        "alice",
		Password:    "pass123",
	})
	msg, err := s.buildRequest(0)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	// Login card should be first
	if len(msg.Cards) == 0 {
		t.Fatal("no cards")
	}
	login, ok := msg.Cards[0].(*xfer.LoginCard)
	if !ok {
		t.Fatalf("first card is %T, want *LoginCard", msg.Cards[0])
	}
	if login.User != "alice" {
		t.Fatalf("login.User = %q, want alice", login.User)
	}
	if login.Nonce == "" {
		t.Fatal("login.Nonce is empty")
	}
	if login.Signature == "" {
		t.Fatal("login.Signature is empty")
	}
}

// --- processResponse tests ---

func TestProcessResponseStoresFileCard(t *testing.T) {
	s, r := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	content := []byte("artifact from server")
	uuid := hash.SHA1(content)

	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.FileCard{UUID: uuid, Content: content},
	}}
	done, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if done {
		t.Fatal("should not be done (just received a file)")
	}

	// Verify blob was stored
	rid, ok := blob.Exists(r.DB(), uuid)
	if !ok {
		t.Fatalf("blob %s not found after processResponse", uuid)
	}
	if rid <= 0 {
		t.Fatalf("rid = %d, want > 0", rid)
	}
	if s.result.FilesRecvd != 1 {
		t.Fatalf("FilesRecvd = %d, want 1", s.result.FilesRecvd)
	}
}

// TestProcessResponseDeltaBeforeBaseDoesNotError is the sync-pull acceptance
// test for issue #57 (folded into #53): a delta arriving before its base is
// normal transfer steady state, not a fault. processResponse must succeed
// and (via storeReceivedFile's loadDBPhantoms call) discover the newly
// phantomized base so it gets gimme'd on a later round, rather than
// failing the pull outright.
func TestProcessResponseDeltaBeforeBaseDoesNotError(t *testing.T) {
	s, r := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	base := []byte("pull delta-before-base test, content long enough to compress well")
	target := []byte("pull delta-before-base test, content long enough to compress well, v2")
	deltaBytes, err := delta.Create(base, target)
	if err != nil {
		t.Fatalf("delta.Create: %v", err)
	}
	baseUUID := hash.SHA1(base)
	targetUUID := hash.SHA1(target)

	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.CFileCard{UUID: targetUUID, DeltaSrc: baseUUID, Content: deltaBytes},
	}}
	if _, err := s.processResponse(context.Background(), resp); err != nil {
		t.Fatalf("processResponse(delta before base) = %v, want nil", err)
	}

	targetRid, ok := blob.Exists(r.DB(), targetUUID)
	if !ok {
		t.Fatal("target blob missing after processResponse")
	}
	var size int64
	r.DB().QueryRow("SELECT size FROM blob WHERE rid=?", targetRid).Scan(&size)
	if size < 0 {
		t.Fatalf("target size = %d, want >= 0 (must not be phantomized)", size)
	}
	if _, available := content.AvailableByUUID(r.DB(), targetUUID); available {
		t.Fatal("target reported available before its base ever arrived")
	}

	// loadDBPhantoms (already called unconditionally from handleFileCard)
	// must have discovered the newly phantomized base and queued it for a
	// gimme card on a later round.
	if !s.phantoms[baseUUID] {
		t.Fatal("base UUID not queued for re-request after being phantomized")
	}
}

func TestProcessResponseIGotAddsPhantom(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	missingUUID := "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"
	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.IGotCard{UUID: missingUUID},
	}}
	_, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if !s.remoteHas[missingUUID] {
		t.Fatal("remoteHas should contain the UUID")
	}
	if !s.phantoms[missingUUID] {
		t.Fatal("phantoms should contain the UUID (pull=true, blob missing)")
	}
}

func TestProcessResponseIGotNoPhantomWhenExists(t *testing.T) {
	s, r := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	// Store a blob so it exists locally
	content := []byte("already have this")
	_, uuid, err := blob.Store(r.DB(), content)
	if err != nil {
		t.Fatalf("blob.Store: %v", err)
	}

	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.IGotCard{UUID: uuid},
	}}
	_, err = s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if !s.remoteHas[uuid] {
		t.Fatal("remoteHas should contain the UUID")
	}
	if s.phantoms[uuid] {
		t.Fatal("phantoms should NOT contain the UUID (we already have it)")
	}
}

func TestProcessResponseGimmeAddsPendingSend(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Push: true, ServerCode: "sc", ProjectCode: testPC})

	wantUUID := "cccccccccccccccccccccccccccccccccccccccc"
	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.GimmeCard{UUID: wantUUID},
	}}
	done, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if done {
		t.Fatal("should not be done (gimme received)")
	}
	if !s.pendingSend[wantUUID] {
		t.Fatal("pendingSend should contain the UUID")
	}
}

func TestProcessResponseCookieCached(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.CookieCard{Value: "session-abc-123"},
	}}
	_, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if s.cookie != "session-abc-123" {
		t.Fatalf("cookie = %q, want session-abc-123", s.cookie)
	}
}

func TestProcessResponseConvergence(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	// Empty response with no pending work = converged
	resp := &xfer.Message{}
	done, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if !done {
		t.Fatal("should be done (empty response, no pending work)")
	}
}

func TestProcessResponseErrorCard(t *testing.T) {
	s, _ := newTestSession(t, SyncOpts{Pull: true, ServerCode: "sc", ProjectCode: testPC})

	resp := &xfer.Message{Cards: []xfer.Card{
		&xfer.ErrorCard{Message: "access denied"},
	}}
	done, err := s.processResponse(context.Background(), resp)
	if err != nil {
		t.Fatalf("processResponse: %v", err)
	}
	if !done {
		t.Fatal("should be done (only error, no work to do)")
	}
	if len(s.result.Errors) != 1 {
		t.Fatalf("Errors = %d, want 1", len(s.result.Errors))
	}
	if s.result.Errors[0] != "error: access denied" {
		t.Fatalf("error = %q", s.result.Errors[0])
	}
}

// --- Sync convergence loop tests ---

func TestSyncSingleRound(t *testing.T) {
	r := setupSyncTestRepo(t)
	mt := &MockTransport{
		Handler: func(req *xfer.Message) *xfer.Message {
			return &xfer.Message{} // empty = converge
		},
	}
	result, err := Sync(context.Background(), r, mt, SyncOpts{
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	if err != nil {
		t.Fatalf("Sync: %v", err)
	}
	if result.Rounds != 1 {
		t.Fatalf("Rounds = %d, want 1", result.Rounds)
	}
}

func TestSyncMultiRound(t *testing.T) {
	r := setupSyncTestRepo(t)

	// Content for the file we'll receive in round 2
	fileContent := []byte("artifact from multi-round sync")
	fileUUID := hash.SHA1(fileContent)

	round := 0
	mt := &MockTransport{
		Handler: func(req *xfer.Message) *xfer.Message {
			round++
			switch round {
			case 1:
				// Round 1: server says "igot" for a blob we don't have
				return &xfer.Message{Cards: []xfer.Card{
					&xfer.IGotCard{UUID: fileUUID},
				}}
			case 2:
				// Round 2: server sends the file we asked for
				return &xfer.Message{Cards: []xfer.Card{
					&xfer.FileCard{UUID: fileUUID, Content: fileContent},
				}}
			default:
				// Round 3+: empty = converge
				return &xfer.Message{}
			}
		},
	}
	result, err := Sync(context.Background(), r, mt, SyncOpts{
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	if err != nil {
		t.Fatalf("Sync: %v", err)
	}
	if result.Rounds != 3 {
		t.Fatalf("Rounds = %d, want 3", result.Rounds)
	}
	if result.FilesRecvd != 1 {
		t.Fatalf("FilesRecvd = %d, want 1", result.FilesRecvd)
	}
	// Verify the blob ended up in the repo
	_, ok := blob.Exists(r.DB(), fileUUID)
	if !ok {
		t.Fatal("file not stored after multi-round sync")
	}
}

func TestSyncContextCancellation(t *testing.T) {
	r := setupSyncTestRepo(t)
	ctx, cancel := context.WithCancel(context.Background())
	cancel() // cancel immediately

	mt := &MockTransport{
		Handler: func(req *xfer.Message) *xfer.Message {
			return &xfer.Message{}
		},
	}
	_, err := Sync(ctx, r, mt, SyncOpts{
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	if err == nil {
		t.Fatal("expected error from cancelled context")
	}
	if err != context.Canceled {
		t.Fatalf("error = %v, want context.Canceled", err)
	}
}

func TestSyncMaxRoundsExceeded(t *testing.T) {
	r := setupSyncTestRepo(t)

	// Mock that never converges: always returns a gimme card
	mt := &MockTransport{
		Handler: func(req *xfer.Message) *xfer.Message {
			return &xfer.Message{Cards: []xfer.Card{
				&xfer.GimmeCard{UUID: "dddddddddddddddddddddddddddddddddddddddd"},
			}}
		},
	}
	result, err := Sync(context.Background(), r, mt, SyncOpts{
		Push:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
	})
	if err == nil {
		t.Fatal("expected error for max rounds exceeded")
	}
	if result.Rounds != MaxRounds {
		t.Fatalf("Rounds = %d, want %d", result.Rounds, MaxRounds)
	}
}

// --- Benchmarks ---

// BenchmarkBuildRequest benchmarks buildRequest with 100 unclustered artifacts.
func BenchmarkBuildRequest(b *testing.B) {
	path := filepath.Join(b.TempDir(), "bench.fossil")
	r, err := repo.Create(path, "benchuser", simio.CryptoRand{}, testPC)
	if err != nil {
		b.Fatalf("repo.Create: %v", err)
	}
	defer r.Close()

	// Populate 100 unclustered artifacts
	for i := 0; i < 100; i++ {
		content := []byte(fmt.Sprintf("benchmark artifact %d", i))
		_, _, err := blob.Store(r.DB(), content)
		if err != nil {
			b.Fatalf("blob.Store: %v", err)
		}
	}

	s := newSession(r, SyncOpts{
		Push:        true,
		Pull:        true,
		ServerCode:  "sc",
		ProjectCode: testPC,
		User:        "alice",
		Password:    "secret",
	})

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := s.buildRequest(0)
		if err != nil {
			b.Fatalf("buildRequest: %v", err)
		}
	}
}

// BenchmarkProcessResponse benchmarks processResponse with 50 file cards.
func BenchmarkProcessResponse(b *testing.B) {
	path := filepath.Join(b.TempDir(), "bench.fossil")
	r, err := repo.Create(path, "benchuser", simio.CryptoRand{}, testPC)
	if err != nil {
		b.Fatalf("repo.Create: %v", err)
	}
	defer r.Close()

	// Build a message with 50 file cards
	var cards []xfer.Card
	for i := 0; i < 50; i++ {
		content := []byte(fmt.Sprintf("benchmark file content %d", i))
		uuid := hash.SHA1(content)
		cards = append(cards, &xfer.FileCard{UUID: uuid, Content: content})
	}
	msg := &xfer.Message{Cards: cards}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		b.StopTimer()
		// Each iteration needs a fresh session+repo because processResponse stores blobs
		bpath := filepath.Join(b.TempDir(), fmt.Sprintf("bench-%d.fossil", i))
		br, err := repo.Create(bpath, "benchuser", simio.CryptoRand{}, testPC)
		if err != nil {
			b.Fatalf("repo.Create: %v", err)
		}
		s := newSession(br, SyncOpts{
			Pull:        true,
			ServerCode:  "sc",
			ProjectCode: testPC,
		})
		b.StartTimer()

		_, err = s.processResponse(context.Background(), msg)
		if err != nil {
			b.Fatalf("processResponse: %v", err)
		}

		b.StopTimer()
		br.Close()
	}
}