Heal the layer break around the Id<> type

src/sql/api.ts

@@ -1,12 +1,23 @@
 import * as sql from "sql-bricks-postgres";
 
-export type Id<T> = bigint & { __id: T };
+import { Id } from "../model";
 
 export interface Row {
   [key: string]: string;
 }
 
 export interface Transaction {
+  /**
+   * Generate a new random primary key.
+   *
+   * On SQLite this is a random 63-bit integer (the high bit is always zero
+   * so that all IDs are positive, mostly for aesthetic reasons although this
+   * may also usefully reserve a namespace for automated testing).
+   *
+   * On Postgres this might generate UUIDv4s instead.
+   */
+  generateId<T>(): Id<T>;
+
   modify(stmt: sql.Statement): Promise<void>;
 
   fetchRow(stmt: sql.SelectStatement): Promise<Row | undefined>;

src/sql/index.ts

@@ -1,3 +1,2 @@
 export * from "./api";
 export * from "./sqlite";
-export * from "./util";

src/sql/sqlite.ts

@@ -1,7 +1,9 @@
 import Database from "better-sqlite3";
+import { randomBytes } from "crypto";
 import * as sql from "sql-bricks-postgres";
 
 import { DataSource, Row, Transaction } from "./api";
+import { Id } from "../model";
 
 type MixedRow = {
   [key: string]: any;
@@ -52,6 +54,17 @@ function _postprocess(obj: MixedRow): Row {
 class SqliteTransaction implements Transaction {
   constructor(private readonly _db: Database.Database) {}
 
+  generateId<T>(): Id<T> {
+    const buf = randomBytes(8);
+
+    buf[0] &= 0x7f; // Force number to be non-negative
+
+    const val = buf.readBigUInt64BE(0);
+    const str = val.toString();
+
+    return str as Id<T>;
+  }
+
   modify(stmt: sql.Statement): Promise<void> {
     const params = _preprocess(stmt);
 

src/sql/util.ts

@@ -1,14 +0,0 @@
-import { randomBytes } from "crypto";
-
-export function generateId(): bigint {
-  const buf = randomBytes(8);
-
-  buf[0] &= 0x7f; // Force number to be non-negative
-
-  // Let's not depend on Node v12 for the sake of 3 LoC just yet.
-
-  const hi = buf.readUInt32BE(0);
-  const lo = buf.readUInt32BE(4);
-
-  return (BigInt(hi) << 32n) | BigInt(lo);
-}