Add inferRawDocType helper

test/types/schema.test.ts

@@ -4,6 +4,7 @@ import {
   HydratedDocument,
   IndexDefinition,
   IndexOptions,
+  InferRawDocType,
   InferSchemaType,
   InsertManyOptions,
   ObtainDocumentType,
@@ -1230,3 +1231,13 @@ async function gh13797() {
     expectType<IUser>(this); return '';
   } } });
 }
+
+function gh13772() {
+  const schemaDefinition = {
+    name: String,
+    docArr: [{ name: String }]
+  };
+  const schema = new Schema(schemaDefinition);
+  type RawDocType = InferRawDocType<typeof schemaDefinition>;
+  expectAssignable<{ name?: string, docArr?: Array<{ name?: string }> }>({} as RawDocType);
+}

types/index.d.ts

@@ -20,6 +20,7 @@
 /// <reference path="./types.d.ts" />
 /// <reference path="./utility.d.ts" />
 /// <reference path="./validation.d.ts" />
+/// <reference path="./inferrawdoctype.d.ts" />
 /// <reference path="./inferschematype.d.ts" />
 /// <reference path="./virtuals.d.ts" />
 /// <reference path="./augmentations.d.ts" />

types/inferrawdoctype.d.ts

@@ -0,0 +1,169 @@
+declare module 'mongoose' {
+  export type InferRawDocType<
+    DocDefinition,
+    TSchemaOptions extends Record<any, any> = DefaultSchemaOptions
+  > = {
+    [
+      K in keyof (RequiredPaths<DocDefinition, TSchemaOptions['typeKey']> &
+      OptionalPaths<DocDefinition, TSchemaOptions['typeKey']>)
+    ]: ObtainRawDocumentPathType<DocDefinition[K], TSchemaOptions['typeKey']>;
+  };
+
+/**
+ * @summary Obtains schema Path type.
+ * @description Obtains Path type by separating path type from other options and calling {@link ResolvePathType}
+ * @param {PathValueType} PathValueType Document definition path type.
+ * @param {TypeKey} TypeKey A generic refers to document definition.
+ */
+type ObtainRawDocumentPathType<
+  PathValueType,
+  TypeKey extends string = DefaultTypeKey
+> = ResolveRawPathType<
+  PathValueType extends PathWithTypePropertyBaseType<TypeKey> ? PathValueType[TypeKey] : PathValueType,
+  PathValueType extends PathWithTypePropertyBaseType<TypeKey> ? Omit<PathValueType, TypeKey> : {},
+  TypeKey
+>;
+
+type IsPathDefaultUndefined<PathType> = PathType extends { default: undefined } ?
+  true :
+  PathType extends { default: (...args: any[]) => undefined } ?
+    true :
+    false;
+
+/**
+ * @summary Checks if a document path is required or optional.
+ * @param {P} P Document path.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ */
+type IsPathRequired<P, TypeKey extends string = DefaultTypeKey> =
+  P extends { required: true | [true, string | undefined] | { isRequired: true } } | ArrayConstructor | any[]
+    ? true
+    : P extends { required: boolean }
+      ? P extends { required: false }
+        ? false
+        : true
+      : P extends (Record<TypeKey, ArrayConstructor | any[]>)
+        ? IsPathDefaultUndefined<P> extends true
+          ? false
+          : true
+        : P extends (Record<TypeKey, any>)
+          ? P extends { default: any }
+            ? IfEquals<P['default'], undefined, false, true>
+            : false
+          : false;
+
+/**
+ * @summary Path base type defined by using TypeKey
+ * @description It helps to check if a path is defined by TypeKey OR not.
+ * @param {TypeKey} TypeKey A literal string refers to path type property key.
+ */
+type PathWithTypePropertyBaseType<TypeKey extends string = DefaultTypeKey> = { [k in TypeKey]: any };
+
+/**
+ * @summary A Utility to obtain schema's required path keys.
+ * @param {T} T A generic refers to document definition.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ * @returns required paths keys of document definition.
+ */
+type RequiredPathKeys<T, TypeKey extends string = DefaultTypeKey> = {
+  [K in keyof T]: IsPathRequired<T[K], TypeKey> extends true ? IfEquals<T[K], any, never, K> : never;
+}[keyof T];
+
+/**
+ * @summary A Utility to obtain schema's required paths.
+ * @param {T} T A generic refers to document definition.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ * @returns a record contains required paths with the corresponding type.
+ */
+type RequiredPaths<T, TypeKey extends string = DefaultTypeKey> = {
+  [K in RequiredPathKeys<T, TypeKey>]: T[K];
+};
+
+/**
+ * @summary A Utility to obtain schema's optional path keys.
+ * @param {T} T A generic refers to document definition.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ * @returns optional paths keys of document definition.
+ */
+type OptionalPathKeys<T, TypeKey extends string = DefaultTypeKey> = {
+  [K in keyof T]: IsPathRequired<T[K], TypeKey> extends true ? never : K;
+}[keyof T];
+
+/**
+ * @param {T} T A generic refers to string path enums.
+ * @returns Path enum values type as literal strings or string.
+ */
+type PathEnumOrString<T extends SchemaTypeOptions<string>['enum']> = T extends ReadonlyArray<infer E> ? E : T extends { values: any } ? PathEnumOrString<T['values']> : string;
+
+/**
+ * @summary A Utility to obtain schema's optional paths.
+ * @param {T} T A generic refers to document definition.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ * @returns a record contains optional paths with the corresponding type.
+ */
+type OptionalPaths<T, TypeKey extends string = DefaultTypeKey> = {
+  [K in OptionalPathKeys<T, TypeKey>]?: T[K];
+};
+
+/**
+ * @summary Resolve path type by returning the corresponding type.
+ * @param {PathValueType} PathValueType Document definition path type.
+ * @param {Options} Options Document definition path options except path type.
+ * @param {TypeKey} TypeKey A generic of literal string type."Refers to the property used for path type definition".
+ * @returns Number, "Number" or "number" will be resolved to number type.
+ */
+type ResolveRawPathType<PathValueType, Options extends SchemaTypeOptions<PathValueType> = {}, TypeKey extends string = DefaultSchemaOptions['typeKey']> =
+  PathValueType extends Schema ? InferRawDocType<PathValueType> :
+    PathValueType extends (infer Item)[] ?
+      IfEquals<Item, never, any[], Item extends Schema ?
+        // If Item is a schema, infer its type.
+        Array<InferRawDocType<Item>> :
+        Item extends Record<TypeKey, any>?
+          Item[TypeKey] extends Function | String ?
+            // If Item has a type key that's a string or a callable, it must be a scalar,
+            // so we can directly obtain its path type.
+            ObtainRawDocumentPathType<Item, TypeKey>[] :
+            // If the type key isn't callable, then this is an array of objects, in which case
+            // we need to call ObtainDocumentType to correctly infer its type.
+            InferRawDocType<Item>[]:
+          ObtainRawDocumentPathType<Item, TypeKey>[]
+      >:
+      PathValueType extends ReadonlyArray<infer Item> ?
+        IfEquals<Item, never, any[], Item extends Schema ?
+          Array<InferRawDocType<Item>> :
+          Item extends Record<TypeKey, any> ?
+            Item[TypeKey] extends Function | String ?
+            ObtainRawDocumentPathType<Item, TypeKey>[] :
+              InferRawDocType<Item>[]:
+              ObtainRawDocumentPathType<Item, TypeKey>[]
+        >:
+        PathValueType extends StringSchemaDefinition ? PathEnumOrString<Options['enum']> :
+          IfEquals<PathValueType, Schema.Types.String> extends true ? PathEnumOrString<Options['enum']> :
+            IfEquals<PathValueType, String> extends true ? PathEnumOrString<Options['enum']> :
+              PathValueType extends NumberSchemaDefinition ? Options['enum'] extends ReadonlyArray<any> ? Options['enum'][number] : number :
+                IfEquals<PathValueType, Schema.Types.Number> extends true ? number :
+                  PathValueType extends DateSchemaDefinition ? Date :
+                    IfEquals<PathValueType, Schema.Types.Date> extends true ? Date :
+                      PathValueType extends typeof Buffer | 'buffer' | 'Buffer' | typeof Schema.Types.Buffer ? Buffer :
+                        PathValueType extends BooleanSchemaDefinition ? boolean :
+                          IfEquals<PathValueType, Schema.Types.Boolean> extends true ? boolean :
+                            PathValueType extends ObjectIdSchemaDefinition ? Types.ObjectId :
+                              IfEquals<PathValueType, Types.ObjectId> extends true ? Types.ObjectId :
+                                IfEquals<PathValueType, Schema.Types.ObjectId> extends true ? Types.ObjectId :
+                                  PathValueType extends 'decimal128' | 'Decimal128' | typeof Schema.Types.Decimal128 ? Types.Decimal128 :
+                                    IfEquals<PathValueType, Schema.Types.Decimal128> extends true ? Types.Decimal128 :
+                                      IfEquals<PathValueType, Types.Decimal128> extends true ? Types.Decimal128 :
+                                        IfEquals<PathValueType, Schema.Types.BigInt> extends true ? bigint :
+                                          PathValueType extends 'bigint' | 'BigInt' | typeof Schema.Types.BigInt ? bigint :
+                                            PathValueType extends 'uuid' | 'UUID' | typeof Schema.Types.UUID ? Buffer :
+                                              IfEquals<PathValueType, Schema.Types.UUID> extends true ? Buffer :
+                                                PathValueType extends MapConstructor ? Map<string, ResolveRawPathType<Options['of']>> :
+                                                  IfEquals<PathValueType, typeof Schema.Types.Map> extends true ? Map<string, ResolveRawPathType<Options['of']>> :
+                                                    PathValueType extends ArrayConstructor ? any[] :
+                                                      PathValueType extends typeof Schema.Types.Mixed ? any:
+                                                        IfEquals<PathValueType, ObjectConstructor> extends true ? any:
+                                                          IfEquals<PathValueType, {}> extends true ? any:
+                                                            PathValueType extends typeof SchemaType ? PathValueType['prototype'] :
+                                                              PathValueType extends Record<string, any> ? ObtainDocumentType<PathValueType, any, { typeKey: TypeKey }> :
+                                                                unknown;
+}