bun-sqlite/src/lib/schema/sync-indexes.ts

import type { Database } from "bun:sqlite";
import type { BUN_SQLITE_TableSchemaType } from "../../types";
import { sqlQuoteIdent as q } from "../../utils/sql-safe";

type Params = {
    db: Database;
    table: BUN_SQLITE_TableSchemaType;
};

/**
 * Sync indexes for a table
 */
export default function syncIndexes({ db, table }: Params) {
    if (!table.indexes || table.indexes.length === 0) {
        return;
    }

    const existingIndexes = (
        db
            .query(
                `SELECT name FROM sqlite_master WHERE type='index' AND tbl_name=? AND name NOT LIKE 'sqlite_%'`,
            )
            .all(table.tableName) as { name: string }[]
    ).map((r) => r.name);

    // Drop indexes not in schema
    for (const indexName of existingIndexes) {
        const stillExists = table.indexes.some(
            (idx) => idx.indexName === indexName,
        );
        if (!stillExists) {
            console.log(`Dropping index: ${indexName}`);
            db.run(`DROP INDEX IF EXISTS ${q(indexName)}`);
        }
    }

    // Create new indexes
    for (const index of table.indexes) {
        if (!index.indexName || !index.indexTableFields?.length) {
            continue;
        }

        if (!existingIndexes.includes(index.indexName)) {
            console.log(`Creating index: ${index.indexName}`);
            const fields = index.indexTableFields
                .map((f) => q(String(f)))
                .join(", ");
            db.run(
                `CREATE INDEX ${q(index.indexName)} ON ${q(table.tableName)} (${fields})`,
            );
        }
    }
}