Groups

group lets you run different validations on the same container depending on what the call is doing. The classic case: create requires a password, update doesn't.

Mount-time group

const user = new Container<{ name: string; email: string; password: string }>();

user.mount('name',     isString);
user.mount('email',    isEmail);
user.mount('password', { group: ['create'] }, isStrongPassword);

A mount with group only runs when:

• options.group matches one of the mount's groups, or
• the mount's group includes '*' (wildcard), or
• the run was started with group: '*' (wildcard at the run level forces every mount to run).

Mounts with no group declared run for every group, including the default (no group) call.

Run-time group

await user.run(input, { group: 'create' });
// → name, email, password all run

await user.run(input, { group: 'update' });
// → name, email run; password is skipped

await user.run(input);
// → name, email run; password is skipped (no group ⇢ no match)

await user.run(input, { group: '*' });
// → every mount runs regardless of declared group

Multiple groups per mount

user.mount('twoFactorCode', { group: ['create', 'verify'] }, isCode);

The mount runs when the active group is 'create' or 'verify'.

Combining with paths

Groups and paths are independent — both filters must let the mount through. A common pattern is an update group that explicitly omits required fields by not registering them under that group:

class UserContainer extends Container<{ name: string; email: string; password: string }> {
    protected initialize() {
        // Required for both create and update
        this.mount('name',  isString);
        this.mount('email', isEmail);

        // Required only for create
        this.mount('password', { group: ['create'] }, isStrongPassword);

        // Optional patch fields, only on update
        this.mount('avatarUrl', { group: ['update'], optional: true }, isUrl);
    }
}

Wildcard semantics

Combination	Behavior
Mount has no group	Runs for every group (including no group)
Mount group ['create']	Runs only when run group is 'create' (or '*')
Mount group ['*']	Runs for every group
Run group '*'	Forces every mount to run, ignoring its declared group
Run group undefined	Only mounts without a group declaration run