database-specific replacers

Author: mbostock

bin/query.ts

@@ -4,6 +4,7 @@ import {mkdir, writeFile} from "node:fs/promises";
 import {dirname, join} from "node:path";
 import {parseArgs} from "node:util";
 import {getDatabase, getDatabaseConfig, getQueryCachePath} from "../src/databases/index.js";
+import {getReplacer} from "../src/databases/index.js";
 
 if (process.argv[1] === import.meta.filename) run();
 
@@ -52,20 +53,14 @@ export default async function run(args?: string[]): Promise<void> {
     const database = await getDatabase(config);
     const results = await database.call(null, strings, ...params);
     await mkdir(dirname(cachePath), {recursive: true});
-    await writeFile(cachePath, JSON.stringify(results, replace));
+    await writeFile(cachePath, JSON.stringify(results, await getReplacer(config)));
     console.log(join(values.root, cachePath));
   } catch (error) {
     console.error(getErrorMessage(error));
     process.exit(1);
   }
 }
 
-// Force dates to be serialized as ISO 8601 UTC, undoing this:
-// https://github.com/snowflakedb/snowflake-connector-nodejs/blob/a9174fb7/lib/connection/result/sf_timestamp.js#L177-L179
-function replace(this: {[key: string]: unknown}, key: string, value: unknown): unknown {
-  return this[key] instanceof Date ? Date.prototype.toJSON.call(this[key]) : value;
-}
-
 function getErrorMessage(error: unknown): string {
   return error instanceof Error &&
     "errors" in error && // AggregateError

src/databases/bigquery.ts

@@ -1,4 +1,5 @@
 import {BigQuery} from "@google-cloud/bigquery";
+import {BigQueryDate, BigQueryDatetime, BigQueryTimestamp} from "@google-cloud/bigquery";
 import type {TableField, TableSchema} from "@google-cloud/bigquery";
 import type {BigQueryConfig, QueryTemplateFunction} from "./index.js";
 import type {ColumnSchema} from "../runtime/index.js";
@@ -55,3 +56,12 @@ function getColumnType({type, mode}: TableField): ColumnSchema["type"] {
       return "string";
   }
 }
+
+export function replacer(this: {[key: string]: unknown}, key: string, value: unknown): unknown {
+  const v = this[key];
+  return v instanceof BigQueryDate ||
+    v instanceof BigQueryDatetime ||
+    v instanceof BigQueryTimestamp
+    ? new Date(v.value).toJSON()
+    : value;
+}

src/databases/index.ts

@@ -106,6 +106,17 @@ export async function getDatabase(config: DatabaseConfig): Promise<QueryTemplate
   }
 }
 
+export type Replacer = (this: {[key: string]: unknown}, key: string, value: unknown) => unknown;
+
+export async function getReplacer(config: DatabaseConfig): Promise<Replacer | undefined> {
+  switch (config.type) {
+    case "bigquery":
+      return (await import("./bigquery.js")).replacer;
+    case "snowflake":
+      return (await import("./snowflake.js")).replacer;
+  }
+}
+
 export async function getQueryCachePath(
   sourcePath: string,
   databaseName: string,

src/databases/snowflake.ts

@@ -111,3 +111,10 @@ function getColumnType(column: Column): ColumnSchema["type"] {
       return "other";
   }
 }
+
+// Force dates to be serialized as ISO 8601 UTC, undoing this:
+// https://github.com/snowflakedb/snowflake-connector-nodejs/blob/a9174fb7/lib/connection/result/sf_timestamp.js#L177-L179
+export function replacer(this: {[key: string]: unknown}, key: string, value: unknown): unknown {
+  const v = this[key];
+  return v instanceof Date ? Date.prototype.toJSON.call(v) : value;
+}