mobx-keystone/src/types/objectBased/typesDataModelData.ts

A MobX powered state management solution based on data trees with first class support for TypeScript, snapshots, patches and much more

import type { O } from "ts-toolbelt"
import type { AnyDataModel } from "../../dataModel/BaseDataModel"
import { getDataModelMetadata } from "../../dataModel/getDataModelMetadata"
import { isDataModelClass } from "../../dataModel/utils"
import type {
  ModelClass,
  ModelData,
  ModelUntransformedData,
} from "../../modelShared/BaseModelShared"
import { modelInfoByClass } from "../../modelShared/modelInfo"
import { getInternalModelClassPropsInfo } from "../../modelShared/modelPropsInfo"
import { noDefaultValue } from "../../modelShared/prop"
import { failure, lazy } from "../../utils"
import {
  TypeChecker,
  TypeCheckerBaseType,
  TypeInfo,
  TypeInfoGen,
  lateTypeChecker,
} from "../TypeChecker"
import { getTypeInfo } from "../getTypeInfo"
import { registerStandardTypeResolver, resolveTypeChecker } from "../resolveTypeChecker"
import type { AnyStandardType, IdentityType } from "../schemas"

const cachedDataModelTypeChecker = new WeakMap<ModelClass<AnyDataModel>, TypeChecker>()

type _Class<T> = abstract new (...args: any[]) => T
type _ClassOrObject<M, K> = K extends M ? object : _Class<K> | (() => _Class<K>)

/**
 * A type that represents a data model data.
 * The type referenced in the model decorator will be used for type checking.
 *
 * Example:
 * ```ts
 * const someDataModelDataType = types.dataModelData(SomeModel)
 * // or for recursive models
 * const someDataModelDataType = types.dataModelData<SomeModel>(() => SomeModel)
 * ```
 *
 * @template M Data model type.
 * @param modelClass Model class.
 * @returns
 */
export function typesDataModelData<M = never, K = M>(
  modelClass: _ClassOrObject<M, K>
): IdentityType<
  | ModelUntransformedData<
      K extends M ? (M extends AnyDataModel ? M : never) : K extends AnyDataModel ? K : never
    >
  | ModelData<
      K extends M ? (M extends AnyDataModel ? M : never) : K extends AnyDataModel ? K : never
    >
> {
  // if we type it any stronger then recursive defs and so on stop working

  if (!isDataModelClass(modelClass) && typeof modelClass === "function") {
    // resolve later
    const modelClassFn = modelClass as () => ModelClass<AnyDataModel>
    const typeInfoGen: TypeInfoGen = (t) => new DataModelDataTypeInfo(t, modelClassFn())
    return lateTypeChecker(() => typesDataModelData(modelClassFn()) as any, typeInfoGen) as any
  } else {
    const modelClazz: ModelClass<AnyDataModel> = modelClass as any

    const cachedTypeChecker = cachedDataModelTypeChecker.get(modelClazz)
    if (cachedTypeChecker) {
      return cachedTypeChecker as any
    }

    const typeInfoGen: TypeInfoGen = (t) => new DataModelDataTypeInfo(t, modelClazz)

    const tc = lateTypeChecker(() => {
      const modelInfo = modelInfoByClass.get(modelClazz)!
      const typeName = `DataModelData(${modelInfo.name})`

      const dataTypeChecker = getDataModelMetadata(modelClazz).dataType
      if (!dataTypeChecker) {
        throw failure(
          `type checking cannot be performed over data model data of type '${modelInfo.name}' since that model type has no data type declared, consider adding a data type or using types.unchecked() instead`
        )
      }

      const resolvedDataTypeChecker = resolveTypeChecker(dataTypeChecker)

      const thisTc: TypeChecker = new TypeChecker(
        TypeCheckerBaseType.Object,

        (value, path, typeCheckedValue) => {
          return resolvedDataTypeChecker.check(value, path, typeCheckedValue)
        },

        () => typeName,
        typeInfoGen,

        (value) => {
          return resolvedDataTypeChecker.snapshotType(value) ? thisTc : null
        },

        (sn: Record<string, unknown>) => {
          return resolvedDataTypeChecker.fromSnapshotProcessor(sn)
        },

        (sn: Record<string, unknown>) => {
          return resolvedDataTypeChecker.toSnapshotProcessor(sn)
        }
      )

      return thisTc
    }, typeInfoGen) as any

    cachedDataModelTypeChecker.set(modelClazz, tc)

    return tc
  }
}

/**
 * `types.dataModelData` type info for a model props.
 */
export interface DataModelDataTypeInfoProps {
  readonly [propName: string]: Readonly<{
    type: AnyStandardType | undefined
    typeInfo: TypeInfo | undefined
    hasDefault: boolean
    default: any
  }>
}

/**
 * `types.dataModelData` type info.
 */
export class DataModelDataTypeInfo extends TypeInfo {
  private _props = lazy(() => {
    const objSchema = getInternalModelClassPropsInfo(this.modelClass)

    const propTypes: O.Writable<DataModelDataTypeInfoProps> = {}
    Object.keys(objSchema).forEach((propName) => {
      const propData = objSchema[propName]

      const type = propData._typeChecker as any as AnyStandardType | undefined

      let typeInfo: TypeInfo | undefined
      if (type) {
        typeInfo = getTypeInfo(type)
      }

      let hasDefault = false
      let defaultValue: any
      if (propData._defaultFn !== noDefaultValue) {
        defaultValue = propData._defaultFn
        hasDefault = true
      } else if (propData._defaultValue !== noDefaultValue) {
        defaultValue = propData._defaultValue
        hasDefault = true
      }

      propTypes[propName] = {
        type,
        typeInfo,
        hasDefault,
        default: defaultValue,
      }
    })
    return propTypes
  })

  get props(): DataModelDataTypeInfoProps {
    return this._props()
  }

  get modelType(): string {
    const modelInfo = modelInfoByClass.get(this.modelClass)!
    return modelInfo.name
  }

  constructor(
    thisType: AnyStandardType,
    readonly modelClass: ModelClass<AnyDataModel>
  ) {
    super(thisType)
  }
}

/**
 * @internal
 */
export function registerDataModelDataStandardTypeResolver() {
  registerStandardTypeResolver((v) => (isDataModelClass(v) ? typesDataModelData(v) : undefined))
}