fix problem with initialization & refactor types

src/interfaces/database.ts

@@ -9,6 +9,6 @@ export interface DatabaseService {
   initialize(): Promise<void>;
   query(sql: string, params?: any[]): Promise<QueryExecResult[]>;
   run(sql: string, params?: any[]): Promise<{ changes: number; lastId?: number }>;
-  get(sql: string, params?: any[]): Promise<any[] | undefined>;
+  getOneRow(sql: string, params?: any[]): Promise<any[] | undefined>;
-  all(sql: string, params?: any[]): Promise<any[][]>;
+  getAll(sql: string, params?: any[]): Promise<any[][]>;
-} 
+}

src/services/database.ts

@@ -6,8 +6,9 @@ declare module 'absurd-sql/dist/indexeddb-backend';
 import initSqlJs from '@jlongster/sql.js';
 import { SQLiteFS } from 'absurd-sql';
 import IndexedDBBackend from 'absurd-sql/dist/indexeddb-backend';
+
 import { runMigrations } from '../db-sql/migration';
-import { QueryExecResult } from './migrationService';
+import type { QueryExecResult } from '../interfaces/database';
 
 interface SQLDatabase {
   exec: (sql: string, params?: any[]) => Promise<QueryExecResult[]>;
@@ -73,12 +74,13 @@ class DatabaseService {
     return this.db!.run(sql, params);
   }
 
+  // Note that the resulting array may be empty if there are no results from the query
   async query(sql: string, params: any[] = []): Promise<QueryExecResult[]> {
     this.ensureInitialized();
     return this.db!.exec(sql, params);
   }
 
-  async get(sql: string, params: any[] = []): Promise<any[] | undefined> {
+  async getOneRow(sql: string, params: any[] = []): Promise<any[] | undefined> {
     this.ensureInitialized();
     const result = await this.db!.exec(sql, params);
     return result[0]?.values[0];

src/services/migrationService.ts

@@ -1,9 +1,4 @@
-type SqlValue = string | number | null | Uint8Array;
+import { QueryExecResult } from '../interfaces/database';
-
-export interface QueryExecResult {
-  columns: Array<string>;
-  values: Array<Array<SqlValue>>;
-}
 
 interface Migration {
   name: string;
@@ -36,13 +31,17 @@ export class MigrationService {
         id INTEGER PRIMARY KEY AUTOINCREMENT,
         name TEXT NOT NULL UNIQUE,
         executed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
-      )
+      );
     `);
 
     // Get list of executed migrations
-    const result = await sqlExec('SELECT name FROM migrations');
+    const result: QueryExecResult[] = await sqlExec('SELECT name FROM migrations;');
-    const singleResult = result[0];
+    let executedMigrations: Set<string> = new Set();
-    const executedMigrations = new Set(singleResult.values.map(row => row[0]));
+    // Even with that query, the QueryExecResult may be [] (which doesn't make sense to me).
+    if (result.length > 0) {
+      const singleResult = result[0];
+      executedMigrations = new Set(singleResult.values.map((row: any[]) => row[0]));
+    }
 
     // Run pending migrations in order
     for (const migration of this.migrations) {