msw-azure-kusto

TypeScript Azure Data Explorer (Kusto) HTTP emulator for local testing with MSW.

Disclaimer: Primarily coded by Codex and Opus, this emulator is not feature complete. Only inline ingestion and URI-based CSV ingestion.

Usage

1. Install msw (https://mswjs.io/docs/getting-started)
2. Install msw-azure-kusto
3. Import handlers from msw-azure-kusto and pass them to your MSW setup

CLI emulator

You can run a standalone local Kusto emulator with npx:

npx msw-azure-kusto --port 80 --dashboard 4000

Flags:

• --port (-p) HTTP port for the Kusto emulator endpoints.
• --dashboard Optional dashboard UI port.

Install

npm install msw-azure-kusto

Setup

import { setupServer } from "msw/node";
import { handlers } from "msw-azure-kusto";

export const server = setupServer(...handlers());

azure-kusto-data client example

msw-azure-kusto emulates Kusto REST endpoints such as https://<cluster>/v1/rest/mgmt and https://<cluster>/v2/rest/query. Use your normal azure-kusto-data client setup and point it at a mocked cluster host.

import { Client, KustoConnectionStringBuilder } from "azure-kusto-data";
import { setupServer } from "msw/node";
import { handlers } from "msw-azure-kusto";

const server = setupServer(...handlers());
server.listen();

const cluster = "https://example.kusto.windows.net";
const kcsb = KustoConnectionStringBuilder.withTokenProvider(cluster, async () => "mock-token");
const client = new Client(kcsb);

await client.executeMgmt("Samples", ".create table StormEvents (EventId:int, State:string, Damage:int)");
await client.executeMgmt("Samples", ".ingest inline into table StormEvents <| 1,WA,10\n2,CA,20\n3,WA,5");

const response = await client.executeQuery(
  "Samples",
  "StormEvents | where State == 'WA' | project EventId, State",
);

const primary = response.primaryResults[0];
const json = primary?.toJSON() as { data: Array<Record<string, unknown>> };
console.log(json.data);

await client.close();
server.close();

Supported hosts:

• https://*.kusto.windows.net
• https://kusto.local

Snapshot tests

Snapshots are in src/tests/snapshots/commands.test.snapshot.ts, based on .kql files in src/tests/commands.

Set CLUSTER in your shell or .env before running command tests, for example:

export CLUSTER="https://kusto.local"

Run snapshot-backed command tests

node --run build
node --env-file-if-exists=.env --test dist/tests/commands.test.js

To run only medium guide command cases:

node --env-file-if-exists=.env --test dist/tests/commands.test.js --test-name-pattern "command - medium-guide"

Update snapshots

node --run build
node --run test-update-snapshots