#Cannot assign an abstract constructor type to a non-abstract constructor type.

13 messages · Page 1 of 1 (latest)

topaz quartz
#

Hello,

I am trying to create a migration generator class for MikroORM, and when following the docs, I get the following error:

  Cannot assign an abstract constructor type to a non-abstract constructor type.

40                 generator: MigrationGenerator,
                   ~~~~~~~~~

Here is my generator class:

import { TSMigrationGenerator } from '@mikro-orm/migrations';
import { IMigrationGenerator } from '@mikro-orm/core';

export class MigrationGenerator extends TSMigrationGenerator implements IMigrationGenerator {
    public override generateMigrationFile(className: string, diff: { up: string[]; down: string[] }): string {
        let ret = `import { Migration } from '@mikro-orm/migrations';\n\n`;

        ret += `export class ${className} extends Migration {\n`;
        ret += `    public override async up(): Promise<void> {\n`;
        diff.up.forEach(sql => ret += this.createStatement(sql, 8));
        ret += `    }\n\n`;

        if (diff.down.length > 0) {
            ret += `    public override async down(): Promise<void> {\n`;
            diff.down.forEach(sql => ret += this.createStatement(sql, 8));
            ret += `    }\n`;
        }

        ret += `}\n`;

        return ret;
    }
}

Here is how I give it to MikroORM:

await MikroORM.init<MySqlDriver>({
    metadataProvider: TsMorphMetadataProvider,
    entities: ['./dist/structures/entities'],
    entitiesTs: ['./src/structures/entities'],
    logger: (message: string) => Logger.info(message),
    debug: true,
    type: 'mysql',
    timezone: '+00:00',
    dbName: process.env.DBNAME,
    user: process.env.DBUSER,
    host: process.env.DBHOST,
    password: process.env.DBPASSWORD,
    port: Number(process.env.DBPORT),
    driverOptions: {
        charset: 'utf8mb4',
        collate: 'utf8mb4_general_ci',
    },
    migrations: {
        generator: MigrationGenerator, // <----- Here
        path: './dist/migrations',
        pathTs: './src/migrations',
    },
});

And here is the link to the docs: https://mikro-orm.io/docs/migrations#using-custom-migrationgenerator

I am not sure what I did incorrectly, please help.
Thank you

azure shore
#

where does that MikroORM value come from? i haven't found it in the docs

#

the one you're calling .init on

#

i put this together so far:

sharp tapirBOT
#
mkantor#0
Playground Link

Preview:```ts
import {TSMigrationGenerator} from "@mikro-orm/migrations"
import {IMigrationGenerator} from "@mikro-orm/core"

export class MigrationGenerator
extends TSMigrationGenerator
implements IMigrationGenerator
{
public override generateMigrationFile(
className: string,
diff: {up: strin
...```

You can choose specific lines to embed by selecting them before copying the link.
topaz quartz
azure shore
#

right i get what it is. but where is MikroORM supposed to come from? is it imported? is it a global that's expected to be defined elsewhere?

#

in the playground i linked you'll see it's got a red squiggly and i can't reproduce the generator error because the type of MikroORM.init is unknown

topaz quartz
#

Ah sorry, yes it is imported

azure shore
#

can you show me how that import looks? like i said i couldn't find it

#

just trying to get a repro going in the playground, but i can't without this

topaz quartz
#

... I was importing the wrong class

#

Sorry about this. It's fixed now x_x