Per-Class Configuration (QModel.configure)

QuickModel's global settings (QConfig.configure()) apply to all models. The QModel.configure() static method lets you override specific options for a single class without affecting siblings or the global configuration.

Basic usage

import { Quick, QModel } from 'quickmodel';

interface IDto {
	id: string;
	[key: string]: unknown;
}

@Quick()
class InternalDto extends QModel<IDto> {
	static override readonly config = QModel.configure({
		unknownPropertyPolicy: 'keep',
	});

	declare id: string;
}

The static override readonly config property is the hook that QuickModel reads at construction time. The QModel.configure() factory validates typings — it accepts the same options as IQAdvancedOptions.

Priority order

When an option is set at multiple levels, the most specific one wins:

@Quick() second argument       (highest priority — per call-site)
    ↓
static config = QModel.configure()   (per class)
    ↓
QConfig.configure() defaults         (global)
    ↓
Built-in defaults                    (lowest priority)

Available options

All options from IQAdvancedOptions are available. The most commonly overridden ones:

unknownPropertyPolicy

Controls what happens with payload properties not declared in the model:

@Quick()
class FlexibleDto extends QModel<IFlexibleDto> {
	static override readonly config = QModel.configure({
		unknownPropertyPolicy: 'keep', // preserves extra fields
	});
}

@Quick()
class StrictDto extends QModel<IStrictDto> {
	static override readonly config = QModel.configure({
		unknownPropertyPolicy: 'error', // throws on unknown fields
	});
}

Value	Behavior
'strip'	Silently removes unknown properties (global default)
'keep'	Preserves unknown properties as-is
'error'	Throws error when unknown property is encountered

coercionStrategy

static override readonly config = QModel.configure({
  coercionStrategy: 'loose',  // allows string "123" → number 123
});

nullToUndefined

static override readonly config = QModel.configure({
  nullToUndefined: true,  // null → undefined during population
});

trimStrings / emptyStringAsNull

static override readonly config = QModel.configure({
  normalization: {
    trimStrings: true,
    emptyStringAsNull: true,
  },
});

dateStrategy

Override how Date fields are serialized for this model only:

@Quick({ createdAt: Date })
class TimestampModel extends QModel<ITimestampModel> {
	static override readonly config = QModel.configure({
		dateStrategy: 'timestamp', // serialize as numeric ms, not ISO string
	});

	declare createdAt: Date;
}

exposeUnsetFields

Include undefined and null fields in serialize() output:

static override readonly config = QModel.configure({
  exposeUnsetFields: true,
});

validationTrigger

Run checkRules() automatically on construction:

static override readonly config = QModel.configure({
  validationTrigger: 'construction',
});

transformCase

Transform field names between snake_case and camelCase:

static override readonly config = QModel.configure({
  transformCase: {
    in:  'snake_case',   // incoming: snake_case → camelCase
    out: 'snake_case',   // outgoing: camelCase → snake_case
  },
});

Real-world example

Different serialization per model

// API model: serialize dates as ISO strings (global default)
@Quick({ createdAt: Date })
class ApiResponse extends QModel<IApiResponse> {
	declare createdAt: Date;
}

// Internal model: serialize dates as timestamps for performance
@Quick({ createdAt: Date })
class CacheEntry extends QModel<ICacheEntry> {
	static override readonly config = QModel.configure({
		dateStrategy: 'timestamp',
	});
	declare createdAt: Date;
}

Flexible DTO that preserves extra fields

@Quick()
class EventPayload extends QModel<IEventPayload> {
	static override readonly config = QModel.configure({
		unknownPropertyPolicy: 'keep',
		coercionStrategy: 'loose',
	});

	declare eventType: string;
	declare aggregateId: string;
	// Any additional event-specific fields are preserved
}

Combining with @Quick() second argument

Options passed as the second argument to @Quick() take precedence over static config:

@Quick({}, { unknownPropertyPolicy: 'error' }) // wins over config below
class StrictModel extends QModel<IStrictModel> {
	static override readonly config = QModel.configure({
		unknownPropertyPolicy: 'keep', // overridden by @Quick() arg
	});
}

API reference

Symbol	Description
QModel.configure(opts)	Returns the same opts (typed validation, used as static config)
static readonly config	Per-class override property read by the population service
IQClassConfig	Type alias for the accepted options

See also

• QModel — base class
• Getting Started — global QConfig configuration
• Tracing — per-class trace configuration