Testing

The Drizzle plugin provides an in-memory database to simplify testing, powered by PGLite.

Indexer setup

Register the Drizzle plugin with your indexer. The default configuration automatically creates a PGLite database when running tests.

my-indexer.indexer.ts

import { drizzleStorage, useDrizzleStorage } from "@apibara/plugin-drizzle";
import { drizzle } from "@apibara/plugin-drizzle";
import { StarknetStream } from "@apibara/starknet";
import { defineIndexer } from "apibara/indexer";

import { myTable } from "@/lib/schema";

export default function (runtimeConfig: ApibaraRuntimeConfig) {
  const database = drizzle({
    schema: {
      myTable,
    },
  });

  return defineIndexer(StarknetStream)({
    plugins: [
      drizzleStorage({
        db: database,
      }),
    ],
    async transform({ endCursor, block, context, finality }) {
      const { db } = useDrizzleStorage();

      // Do something with the database
    },
  });
}

Testing

The @apibara/plugin-drizzle package provides two helper functions to work with test databases:

useTestDrizzleStorage: get the Drizzle database object internally created by the plugin.
getTestDatabase: call it with the value returned by the vcr to get the Drizzle database after running the test.

If you need to initialize data in the database, you can add a hook to run:before and initialize the database there.

Example

The following example shows a complete end-te-end test for the indexer.

Pass a custom runtime configuration to the indexer's constructor.
Initialize the database before running the indexer.
Read the data from the database and assert its content with vitest snapshot matching.

test/my-indexer.test.ts

import { describe, expect, it } from "vitest";
import { createVcr } from "apibara/testing";
import { useTestDrizzleStorage } from "@apibara/plugin-drizzle";
import { getTestDatabase } from "@apibara/plugin-drizzle/testing";

// Import the indexer's constructor
import createIndexer from "@/indexers/my-indexer.indexer";

const vcr = createVcr();

describe("my indexer", () => {
  it("should work", async () => {
    const indexer = createIndexer({
      /* runtime configuration */
    });

    const testResult = await vcr.run("ethereum-usdc-transfers", indexer, {
      range: {
        fromBlock: 10_000_000n,
        toBlock: 10_000_005n,
      },
      hooks: {
        "run:before": async () => {
          // Initialize the database
          const db = useTestDrizzleStorage();
          await db.insert(myTable).values({ /* ... */});

        },
      },
    });

    // Get the database created for this test.
    const database = getTestDatabase(testResult);

    // Use the database like any other Drizzle database object
    const rows = await database.select().from(myTable);

    expect(rows.map(({ _id, ...rest }) => rest)).toMatchInlineSnapshot(`
      /* ... */
    `);
  });
});