Show a database target's archive file, size and last write in the target list (closes #397)

Each database target's row on the webhook page names its archive
file, as delivery.ArchivePath finds it, and shows its size on disk and
when it was last written, or "not created yet" when there is no file.
The figures come from the metadata of the file and its -wal only: the
size is the two together, and the last write the later of their
modification times, since a write lands in the -wal first.

Model: opus-5-5

internal/handlers/target_list_test.go

@@ -0,0 +1,71 @@
+package handlers_test
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// TestHandleSourceDetail_ShowsArchiveFile proves a database target's
+// row names its archive file and says "not created yet" before the
+// first write, adds the file's size and last write once it has one row,
+// and says "not created yet" again once the file has been moved away.
+// A target of another type shows no archive file.
+func TestHandleSourceDetail_ShowsArchiveFile(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	archive := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
+	seedTarget(t, db, wh.ID, database.TargetTypeLog)
+
+	path := delivery.ArchivePath(dbMgr, wh, archive)
+
+	body := renderSourceDetailPage(t, h, sess, wh.ID)
+	assert.Equal(t, 1, strings.Count(body, "Archive File:"))
+	assert.Contains(t, body, filepath.Base(path))
+	assert.Contains(t, body, "not created yet")
+	assert.NotContains(t, body, "Archive Size:")
+
+	seedArchive(t, path, 1, 100)
+
+	file, err := os.Stat(path)
+	require.NoError(t, err)
+
+	body = renderSourceDetailPage(t, h, sess, wh.ID)
+	assert.Contains(t, body, filepath.Base(path))
+	assert.NotContains(t, body, "not created yet")
+	assert.Regexp(t,
+		`Archive Size:</span>\s*<span>[1-9][0-9.]* [kM]?B</span>`, body,
+	)
+	assert.Contains(t, body,
+		`title="`+file.ModTime().UTC().Format(time.DateTime)+` UTC"`,
+	)
+
+	require.NoError(t, os.Rename(path, filepath.Join(t.TempDir(), "moved.db")))
+
+	body = renderSourceDetailPage(t, h, sess, wh.ID)
+	assert.Contains(t, body, filepath.Base(path))
+	assert.Contains(t, body, "not created yet")
+	assert.NotContains(t, body, "Archive Size:")
+}