Support for intersection types

This issue has been tracked since 2022-10-26.

Hi @Newbie012 👋 hope things are going great!

Is your feature request related to a problem? Please describe.

It would be great to be able to use intersection types with existing object type aliases to be able to transform existing types instead of copying them throughout the codebase:

type User = {
  id: number;
  username: string;
};

type UserWithPasswordHash = User & {
  passwordHash: string;
};

export async function getUserWithPasswordHashById(id: number) {
  const [user] = await sql<UserWithPasswordHash[]>`
    SELECT
      id,
      username,
      password_hash
    FROM
      users
    WHERE
      id = ${id}
  `;
  return user;
}

Right now, this leads to a crash of ESLint with a confusing error message (as seen here: https://github.com/upleveled/security-vulnerability-examples-next-js-postgres/actions/runs/3330517524/jobs/5509108053):

TypeError: Cannot read properties of undefined (reading 'members')
Occurred while linting /home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/database/users.ts:24
Rule: "@ts-safeql/check-sql"
    at tsTypeToText (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/utils/ts.utils.js:18:34)
    at tsTypeToText (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/utils/ts.utils.js:22:16)
    at getTypeAnnotationState (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/rules/check-sql.rule.js:271:49)
    at /home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/rules/check-sql.rule.js:206:37
    at /home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/fp-ts/lib/Either.js:863:60
    at pipe (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/fp-ts/lib/function.js:300:20)
    at reportCheck (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/rules/check-sql.rule.js:173:29)
    at checkConnectionByTagExpression (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/rules/check-sql.rule.js:236:16)
    at /home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/@ts-safeql/eslint-plugin/lib/rules/check-sql.rule.js:160:16
    at e.run (/home/runner/work/security-vulnerability-examples-next-js-postgres/security-vulnerability-examples-next-js-postgres/node_modules/ts-pattern/dist/index.cjs:1:4927)
error Command failed with exit code 2.

Describe the solution you'd like

It would be great if the intersection types worked

Describe alternatives you've considered

Workaround:

Copy the properties from the other type to the new type (decreasing maintainability):

type User = {
  id: number;
  username: string;
};

type UserWithPasswordHash = {
  id: number;
  username: string;
  passwordHash: string;
};

export async function getUserWithPasswordHashById(id: number) {
  const [user] = await sql<UserWithPasswordHash[]>`
    SELECT
      id,
      username,
      password_hash
    FROM
      users
    WHERE
      id = ${id}
  `;
  return user;
}

Additional context

karlhorky wrote this answer on 2022-10-30

Thanks for the new changes in the release @ts-safeql/[email protected], I'll try them out!

karlhorky wrote this answer on 2022-10-31

@ts-safeql/[email protected] works great, thanks! 🙌

Upgraded to new version in upleveled/security-vulnerability-examples-next-js-postgres#35
Simplified types in upleveled/[email protected]df48c4f

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More Details About Repo

Owner Name	ts-safeql
Repo Name	safeql
Full Name	ts-safeql/safeql
Language	TypeScript
Created Date	2022-09-08
Updated Date	2023-03-16
Star Count	795
Watcher Count	5
Fork Count	14
Issue Count	7

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