fix(history): a SQLite database is a path, not localhost//a/path

apps/web/src/frontend/components/lokee-weave/LokeeWeaveView.tsx

@@ -28,7 +28,11 @@ import { toast } from '../../store/toastStore';
 import { useSyncStore } from '../../store/useSyncStore';
 import { useUiStore } from '../../store/uiStore';
 import { useLokeeHistoryStore } from '../../store/lokeeHistoryStore';
-import { resolveHistoryCompare, sortVersionsNewestFirst } from '../../lib/historyCompare';
+import {
+  databaseLocation,
+  resolveHistoryCompare,
+  sortVersionsNewestFirst,
+} from '../../lib/historyCompare';
 import { SQL_ICON_STROKE } from '../sql-editor/sqlIconStyle';
 
 export interface LokeeWeaveViewProps {
@@ -52,7 +56,7 @@ const EMPTY_DTO: VersionGraphDTO = {
 
 function describe(database: LokeeDatabase | undefined): string | undefined {
   if (!database) return undefined;
-  const where = [database.host, database.database].filter(Boolean).join('/');
+  const where = databaseLocation(database);
   // ` · schema`, not `.schema`: a SQLite path already ends in `.db`, so the
   // dotted form rendered as `/tmp/app.db.main` and read like a file extension.
   const schema = database.schema ? ` · ${database.schema}` : '';

apps/web/src/frontend/lib/historyCompare.test.ts

@@ -5,6 +5,7 @@
  */
 import { describe, expect, it } from 'vitest';
 import {
+  databaseLocation,
   historyVersionLabel,
   lokeeDatabaseLabel,
   resolveHistoryCompare,
@@ -141,3 +142,47 @@ describe('compare-only labelling', () => {
     ).toBe('v7 · before launch — compare only');
   });
 });
+
+describe('databaseLocation', () => {
+  // `localhost//tmp/app.db` — a stray double slash in front of a path, from a
+  // host value that means nothing for a file dialect in the first place.
+  it.each(['sqlite', 'duckdb'])('drops the host for %s', (dialect) => {
+    expect(databaseLocation({ dialect, host: 'localhost', database: '/tmp/app.db' })).toBe(
+      '/tmp/app.db'
+    );
+  });
+
+  it('keeps host and database for a server dialect', () => {
+    expect(databaseLocation({ dialect: 'postgres', host: 'localhost', database: 'foxdb' })).toBe(
+      'localhost/foxdb'
+    );
+  });
+
+  it('does not leave a dangling separator when one half is missing', () => {
+    expect(databaseLocation({ dialect: 'postgres', database: 'foxdb' })).toBe('foxdb');
+    expect(databaseLocation({ dialect: 'postgres', host: 'db.internal' })).toBe('db.internal');
+  });
+
+  it('is empty when there is nothing to show, so callers can fall back', () => {
+    expect(databaseLocation({ dialect: 'sqlite' })).toBe('');
+  });
+});
+
+describe('lokeeDatabaseLabel reads the same way', () => {
+  it('names a SQLite file without inventing a host', () => {
+    expect(
+      lokeeDatabaseLabel({
+        id: 'abc12345',
+        dialect: 'sqlite',
+        host: 'localhost',
+        database: '/tmp/app.db',
+        schema: 'main',
+        versionCount: 3,
+      })
+    ).toBe('SQLITE · /tmp/app.db · main (3 v)');
+  });
+
+  it('falls back to a short id when the database has no location at all', () => {
+    expect(lokeeDatabaseLabel({ id: 'abcdef1234', dialect: 'sqlite' })).toContain('abcdef12');
+  });
+});

apps/web/src/frontend/lib/historyCompare.ts

@@ -93,6 +93,24 @@ export function historyVersionLabel(
   return base;
 }
 
+/**
+ * Where a captured database lives, in the words that dialect uses.
+ *
+ * A file dialect has no host. Joining one on produced `localhost//tmp/app.db` —
+ * a stray double slash in front of a path, from a value that means nothing for
+ * SQLite or DuckDB in the first place.
+ */
+export function databaseLocation(database: {
+  dialect: string;
+  host?: string;
+  database?: string;
+}): string {
+  const path = (database.database ?? '').trim();
+  const isFile = database.dialect === 'sqlite' || database.dialect === 'duckdb';
+  if (isFile) return path;
+  return [database.host, path].filter(Boolean).join('/');
+}
+
 export function lokeeDatabaseLabel(database: {
   id: string;
   dialect: string;
@@ -101,8 +119,7 @@ export function lokeeDatabaseLabel(database: {
   schema?: string;
   versionCount?: number;
 }): string {
-  const where =
-    [database.host, database.database].filter(Boolean).join('/') || database.id.slice(0, 8);
+  const where = databaseLocation(database) || database.id.slice(0, 8);
   const schema = database.schema ? ` · ${database.schema}` : '';
   const versions =
     typeof database.versionCount === 'number' ? ` (${database.versionCount} v)` : '';