1 files changed, 164 insertions, 0 deletions

diff --git a/sidecar/store_test.go b/sidecar/store_test.go
new file mode 100644
index 0000000..85f50e1
--- /dev/null
+++ b/sidecar/store_test.go
@@ -0,0 +1,164 @@
+package sidecar
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+)
+
+func TestAppendCreatesPrivateUnrelatedSidecar(t *testing.T) {
+	repo := testRepo(t)
+	// Store must be independent of a user's restrictive auto-track setting.
+	testJJ(t, repo, "config", "set", "--repo", "snapshot.auto-track", `"none()"`)
+	testJJ(t, repo, "config", "set", "--repo", "git.private-commits", `"description(glob:'secret:*')"`)
+	before := testJJ(t, repo, "status")
+	store, err := Open(repo)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := store.Append(func(current []byte) ([]byte, error) {
+		if len(current) != 0 {
+			t.Fatalf("new store contained %q", current)
+		}
+		return []byte("one\n"), nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := store.Append(func(current []byte) ([]byte, error) {
+		if string(current) != "one\n" {
+			t.Fatalf("second append saw %q", current)
+		}
+		return []byte("two\n"), nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := store.Read()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != "one\ntwo\n" {
+		t.Fatalf("sidecar log = %q", got)
+	}
+	if after := testJJ(t, repo, "status"); after != before {
+		t.Fatalf("working copy changed:\n--- before\n%s--- after\n%s", before, after)
+	}
+	if _, err := os.Stat(filepath.Join(repo, LogFile)); !os.IsNotExist(err) {
+		t.Fatalf("log materialized in the project working copy: %v", err)
+	}
+
+	alias := strings.TrimSpace(testJJ(t, repo, "config", "get", "revset-aliases."+Alias))
+	if alias == "" {
+		t.Fatal("repo-local sidecar alias was not configured")
+	}
+	private := testJJ(t, repo, "config", "get", "git.private-commits")
+	if !containsRevsetName(private, Alias) {
+		t.Fatalf("private commits = %q, missing %s", private, Alias)
+	}
+	if !strings.Contains(private, "secret:*") {
+		t.Fatalf("private commits = %q, previous setting was overwritten", private)
+	}
+	parent := strings.TrimSpace(testJJ(t, repo, "log", "-G", "-r", "exactly("+Alias+", 1)",
+		"-T", "parents.map(|p| p.commit_id()).join(\"\")"))
+	if parent != strings.Repeat("0", 40) {
+		t.Fatalf("sidecar parent = %q, want virtual root", parent)
+	}
+}
+
+func TestLegacyLogIsReadThenImportedOnFirstAppend(t *testing.T) {
+	repo := testRepo(t)
+	legacy := []byte("legacy\n")
+	if err := os.WriteFile(filepath.Join(repo, LogFile), legacy, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	store, err := Open(repo)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, err := store.Read(); err != nil || string(got) != string(legacy) {
+		t.Fatalf("pre-migration read = %q, %v", got, err)
+	}
+	if err := store.Append(func(current []byte) ([]byte, error) {
+		if string(current) != string(legacy) {
+			t.Fatalf("migration callback saw %q", current)
+		}
+		return []byte("sidecar\n"), nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if got, err := store.Read(); err != nil || string(got) != "legacy\nsidecar\n" {
+		t.Fatalf("migrated log = %q, %v", got, err)
+	}
+}
+
+func TestConcurrentAppendsAreSerialized(t *testing.T) {
+	repo := testRepo(t)
+	store, err := Open(repo)
+	if err != nil {
+		t.Fatal(err)
+	}
+	const writers = 6
+	errCh := make(chan error, writers)
+	var wg sync.WaitGroup
+	for range writers {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			errCh <- store.Append(func(current []byte) ([]byte, error) {
+				id := len(strings.Fields(string(current))) + 1
+				return []byte(fmt.Sprintf("%d\n", id)), nil
+			})
+		}()
+	}
+	wg.Wait()
+	close(errCh)
+	for err := range errCh {
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+	got, err := store.Read()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != "1\n2\n3\n4\n5\n6\n" {
+		t.Fatalf("serialized appends = %q", got)
+	}
+}
+
+func testRepo(t *testing.T) string {
+	t.Helper()
+	if _, err := exec.LookPath("jj"); err != nil {
+		t.Skip("jj not installed")
+	}
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("JJ_USER", "test")
+	t.Setenv("JJ_EMAIL", "[email protected]")
+	repo := filepath.Join(home, "repo")
+	if err := os.Mkdir(repo, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	cmd := exec.Command("jj", "git", "init")
+	cmd.Dir = repo
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("jj git init: %v\n%s", err, out)
+	}
+	return repo
+}
+
+func testJJ(t *testing.T, repo string, args ...string) string {
+	t.Helper()
+	cmd := exec.Command("jj", append([]string{"--ignore-working-copy", "--no-pager"}, args...)...)
+	cmd.Dir = repo
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("jj %s: %v\n%s", strings.Join(args, " "), err, out)
+	}
+	return string(out)
+}