Export filterQuery function (fix #10)

Author: IlyaSemenov

.changeset/serious-experts-wait.md

@@ -0,0 +1,7 @@
+---
+"objection-graphql-resolver": minor
+"orchid-graphql": minor
+"graphql-orm": minor
+---
+
+Export `filterQuery` function.

packages/base/src/filter/filter.ts

@@ -0,0 +1,56 @@
+import type { OrmAdapter } from "../orm/orm"
+import { isPlainObject } from "../utils/is-plain-object"
+
+// TODO: per-field definitions
+export type FilterConfig = boolean
+
+export type FieldFilterScalarValue = null | string | number | boolean
+export type FieldFilterValue = FieldFilterScalarValue | Exclude<FieldFilterScalarValue, null>[]
+export type FilterValue = { [property: string]: FieldFilterValue }
+
+export type FilterQueryOptions<Orm extends OrmAdapter, Context = unknown> = {
+	modifiers?: FilterModifiers<Orm, Context>
+} & (Context extends undefined ? {
+	context?: Context
+} : {
+	context: Context
+})
+
+export type FilterModifier<Orm extends OrmAdapter, Context> = (
+	query: Orm["Query"],
+	value: any,
+	context: Context,
+) => Orm["Query"]
+
+export type FilterModifiers<Orm extends OrmAdapter, Context> = Record<string, FilterModifier<Orm, Context>>
+
+export function filterQuery<Orm extends OrmAdapter, Context>(
+	orm: Orm,
+	query: Orm["Query"],
+	filter: FilterValue,
+	options?: FilterQueryOptions<Orm, Context>,
+): Orm["Query"] {
+	const { context, modifiers } = options ?? {}
+
+	if (!filter) {
+		return query
+	}
+	if (!isPlainObject(filter)) {
+		throw new Error(`Invalid filter: ${filter}, must be plain object.`)
+	}
+	for (const [field, value] of Object.entries(filter)) {
+		if (value === undefined) {
+			// Support optional GraphQL arguments in filter
+			continue
+		}
+		if (modifiers?.[field]) {
+			query = modifiers[field](query, value, context!) // TODO improve types, get rid of !
+		} else {
+			const [table_field, op0] = field.split("__")
+			const op = op0?.toLowerCase()
+			// TODO: validate op
+			query = orm.where(query, table_field, op, value)
+		}
+	}
+	return query
+}

packages/base/src/filter/index.ts

@@ -0,0 +1 @@
+export * from "./filter"

packages/base/src/filters/filters.ts

@@ -1,3 +1,4 @@
+export * from "./filter"
 export { OrmAdapter, OrmModifier, SortOrder } from "./orm/orm"
 export { Paginator } from "./paginators/base"
 export { defineCursorPaginator } from "./paginators/cursor"

packages/base/src/index.ts

@@ -2,7 +2,7 @@ import type { GraphQLResolveInfo } from "graphql"
 import type { ResolveTree } from "graphql-parse-resolve-info"
 import { parseResolveInfo } from "graphql-parse-resolve-info"
 
-import type { FiltersDef } from "../filters/filters"
+import type { FilterConfig } from "../filter"
 import type { OrmAdapter } from "../orm/orm"
 import type { Paginator } from "../paginators/base"
 
@@ -16,7 +16,7 @@ export type GraphResolverOptions<Orm extends OrmAdapter, Context> = Pick<
 export interface GraphResolveOptions<Context> {
 	info: GraphQLResolveInfo
 	context: Context
-	filters?: FiltersDef
+	filters?: FilterConfig
 	/** Subfield path if not resolving root query, e.g.: ['user'] */
 	path?: string[]
 }

packages/base/src/resolvers/graph.ts

@@ -1,4 +1,4 @@
-import type { FiltersDef } from "../filters/filters"
+import type { FilterConfig } from "../filter"
 import type { OrmAdapter } from "../orm/orm"
 
 import type {
@@ -10,7 +10,7 @@ import type { TableResolveModifier } from "./table"
 
 export interface RelationResolverOptions<Orm extends OrmAdapter, Context>
 	extends Omit<FieldResolverOptions<Orm, Context>, "modify"> {
-	filters?: FiltersDef
+	filters?: FilterConfig
 	modify?: TableResolveModifier<Orm, Context>
 }
 

packages/base/src/resolvers/relation.ts

@@ -1,5 +1,5 @@
-import type { ApplyFiltersModifier } from "../filters/filters"
-import { apply_filters } from "../filters/filters"
+import type { FilterModifier, FilterValue } from "../filter"
+import { filterQuery } from "../filter"
 import type { OrmAdapter } from "../orm/orm"
 import { run_after_query } from "../utils/run-after"
 
@@ -14,7 +14,7 @@ export interface TableResolverOptions<Orm extends OrmAdapter, Context> {
 	/** allow to filter all table fields without explicitly listing them */
 	allowAllFilters?: boolean
 	fields?: Record<string, SimpleFieldResolver<Orm, Context>>
-	modifiers?: Record<string, ApplyFiltersModifier<Orm, Context>>
+	modifiers?: Record<string, TableFilterModifier<Orm, Context>>
 	modify?: TableResolveModifier<Orm, Context>
 	transform?(instance: any, context: any): void | PromiseLike<void>
 }
@@ -36,11 +36,13 @@ export interface TableResolveContext<Orm extends OrmAdapter, Context>
 	type: string
 }
 
+export type TableFilterModifier<Orm extends OrmAdapter, Context> = FilterModifier<Orm, TableResolveContext<Orm, Context>>
+
 export class TableResolver<Orm extends OrmAdapter, Context> {
 	// Introspection results
 	readonly relations: Set<string>
 	readonly virtual_fields: Set<string>
-	readonly modifiers?: Record<string, ApplyFiltersModifier<Orm, Context>>
+	readonly modifiers?: Record<string, TableFilterModifier<Orm, Context>>
 
 	readonly table_field_resolvers?: Record<string, FieldResolver<Orm, Context>>
 
@@ -121,17 +123,17 @@ export class TableResolver<Orm extends OrmAdapter, Context> {
 			}
 		}
 
-		const allow_all_filters
-			= this.options.allowAllFilters ?? graph.options.allowAllFilters
-
-		const effective_filters = allow_all_filters ? true : filters
+		const filter = context.tree.args?.filter
+		if (filter) {
+			const allowAllFilters = this.options.allowAllFilters ?? graph.options.allowAllFilters
+			const filterConfig = allowAllFilters ? true : filters
 
-		if (effective_filters) {
-			query = apply_filters<Orm, Context>(query, {
-				filters: effective_filters,
-				modifiers: this.modifiers,
-				context,
-			})
+			if (filterConfig) {
+				query = filterQuery<Orm, TableResolveContext<Orm, Context>>(context.graph.orm, query, filter as FilterValue, {
+					modifiers: this.modifiers,
+					context,
+				})
+			}
 		}
 
 		if (transform) {

packages/base/src/resolvers/table.ts

@@ -1,3 +1,3 @@
-export function is_plain_object(obj: any): obj is Record<string, any> {
+export function isPlainObject(obj: any): obj is Record<string, any> {
 	return typeof obj === "object" && !Array.isArray(obj)
 }

packages/base/src/utils/is-plain-object.ts

@@ -124,3 +124,25 @@ query get_all_posts {
 ```
 
 Modifier filters take precedence over database field filters.
+
+## Reusing Filters for External Queries
+
+There are cases where you need to apply the same filtering logic across multiple queries—even those not originating from GraphQL. For example, you might want to return a filtered list of objects, and then meta data about that filtered list of objects.
+
+To achieve this, use the `filterQuery` function:
+
+```ts
+import { filterQuery } from "objection-graphql-resolver"
+
+const posts = await filterQuery(
+  // Base query to filter
+  PostModel.query(),
+  // Filter object, e.g. { public: true }
+  filterObject,
+  // Option - not required
+  {
+    modifiers, // Additional model modifiers
+    context, // Pass to modifiers
+  }
+)
+```