feat(): add plugin, implement the isolated schema generator

.eslintrc.js

@@ -22,5 +22,6 @@ module.exports = {
     '@typescript-eslint/no-explicit-any': 'off',
     '@typescript-eslint/no-use-before-define': 'off',
     '@typescript-eslint/no-non-null-assertion': 'off',
+    '@typescript-eslint/ban-types': 'off',
   },
 };

.gitignore

@@ -18,4 +18,5 @@ test-schema.graphql
 *.test-definitions.ts
 
 # dist
+/lib/src
 /dist

lib/decorators/args-type.decorator.ts

@@ -0,0 +1,14 @@
+import { TypeMetadataStorage } from '../schema-builder/storages/type-metadata.storage';
+
+/**
+ * Decorator that marks a class as a resolver arguments type.
+ */
+export function ArgsType(): ClassDecorator {
+  return (target: Function) => {
+    const metadata = {
+      name: target.name,
+      target,
+    };
+    TypeMetadataStorage.addArgsMetadata(metadata);
+  };
+}

lib/decorators/args.decorator.ts

@@ -2,41 +2,76 @@ import { PipeTransform, Type } from '@nestjs/common';
 import { isObject, isString } from '@nestjs/common/utils/shared.utils';
 import 'reflect-metadata';
 import { GqlParamtype } from '../enums/gql-paramtype.enum';
-import { BasicOptions } from '../external/type-graphql.types';
-import { lazyMetadataStorage } from '../storages/lazy-metadata.storage';
+import { BaseTypeOptions } from '../interfaces';
+import { LazyMetadataStorage } from '../schema-builder/storages/lazy-metadata.storage';
+import { TypeMetadataStorage } from '../schema-builder/storages/type-metadata.storage';
+import { reflectTypeFromMetadata } from '../utils/reflection.utilts';
 import { addPipesMetadata } from './param.utils';
 
-let TypeGqlArg, TypeGqlArgs;
-try {
-  // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const TypeGql = require('type-graphql');
-  TypeGqlArg = TypeGql.Arg;
-  TypeGqlArgs = TypeGql.Args;
-} catch (e) {}
-
-export interface ArgsOptions extends BasicOptions {
+/**
+ * Interface defining options that can be passed to `@Args()` decorator.
+ */
+export interface ArgsOptions extends BaseTypeOptions {
+  /**
+   * Name of the argument.
+   */
   name?: string;
+  /**
+   * Description of the argument.
+   */
+  description?: string;
+  /**
+   * Function that returns a reference to the arguments host class.
+   */
   type: () => any;
 }
-export function Args();
-export function Args(...pipes: (Type<PipeTransform> | PipeTransform)[]);
+
+/**
+ * Resolver method parameter decorator. Extracts the arguments
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of either all arguments or a single specified argument.
+ */
+export function Args(): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the arguments
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of either all arguments or a single specified argument.
+ */
+export function Args(
+  ...pipes: (Type<PipeTransform> | PipeTransform)[]
+): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the arguments
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of either all arguments or a single specified argument.
+ */
 export function Args(
   property: string,
   ...pipes: (Type<PipeTransform> | PipeTransform)[]
-);
+): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the arguments
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of either all arguments or a single specified argument.
+ */
 export function Args(
   options: ArgsOptions,
   ...pipes: (Type<PipeTransform> | PipeTransform)[]
-);
+): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the arguments
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of either all arguments or a single specified argument.
+ */
 export function Args(
   propertyOrOptions?:
     | string
     | (Type<PipeTransform> | PipeTransform)
     | ArgsOptions,
   ...pipes: (Type<PipeTransform> | PipeTransform)[]
-) {
+): ParameterDecorator {
   let typeFn = undefined;
-  let argOptions = {} as BasicOptions;
+  let argOptions = {} as Omit<ArgsOptions, 'type'>;
   let property = propertyOrOptions;
 
   if (
@@ -46,23 +81,49 @@ export function Args(
   ) {
     property = (propertyOrOptions as Record<string, any>).name;
     typeFn = (propertyOrOptions as Record<string, any>).type;
+
+    const basicOptions = propertyOrOptions as ArgsOptions;
     argOptions = {
-      description: (propertyOrOptions as BasicOptions).description,
-      nullable: (propertyOrOptions as BasicOptions).nullable,
-      defaultValue: (propertyOrOptions as BasicOptions).defaultValue,
+      description: basicOptions.description,
+      nullable: basicOptions.nullable,
+      defaultValue: basicOptions.defaultValue,
     };
   }
 
-  return (target, key, index) => {
+  return (target: Object, key: string, index: number) => {
     addPipesMetadata(GqlParamtype.ARGS, property, pipes, target, key, index);
-    property && isString(property)
-      ? TypeGqlArg &&
-        lazyMetadataStorage.store(() =>
-          TypeGqlArg(property, typeFn, argOptions)(target, key, index),
-        )
-      : TypeGqlArgs &&
-        lazyMetadataStorage.store(() =>
-          TypeGqlArgs(typeFn)(target, key, index),
-        );
+
+    LazyMetadataStorage.store(() => {
+      const { typeFn: reflectedTypeFn, options } = reflectTypeFromMetadata({
+        metadataKey: 'design:paramtypes',
+        prototype: target,
+        propertyKey: key,
+        index: index,
+        explicitTypeFn: typeFn,
+        typeOptions: argOptions,
+      });
+
+      const metadata = {
+        target: target.constructor,
+        methodName: key,
+        typeFn: reflectedTypeFn,
+        index,
+        options,
+      };
+
+      if (property && isString(property)) {
+        TypeMetadataStorage.addMethodParamMetadata({
+          kind: 'arg',
+          name: property,
+          description: argOptions.description,
+          ...metadata,
+        });
+      } else {
+        TypeMetadataStorage.addMethodParamMetadata({
+          kind: 'args',
+          ...metadata,
+        });
+      }
+    });
   };
 }

lib/decorators/context.decorator.ts

@@ -3,15 +3,37 @@ import 'reflect-metadata';
 import { GqlParamtype } from '../enums/gql-paramtype.enum';
 import { createGqlPipesParamDecorator } from './param.utils';
 
-export function Context();
-export function Context(...pipes: (Type<PipeTransform> | PipeTransform)[]);
+/**
+ * Resolver method parameter decorator. Extracts the `Context`
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of `Context`.
+ */
+export function Context(): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the `Context`
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of `Context`.
+ */
+export function Context(
+  ...pipes: (Type<PipeTransform> | PipeTransform)[]
+): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the `Context`
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of `Context`.
+ */
 export function Context(
   property: string,
   ...pipes: (Type<PipeTransform> | PipeTransform)[]
-);
+): ParameterDecorator;
+/**
+ * Resolver method parameter decorator. Extracts the `Context`
+ * object from the underlying platform and populates the decorated
+ * parameter with the value of `Context`.
+ */
 export function Context(
   property?: string | (Type<PipeTransform> | PipeTransform),
   ...pipes: (Type<PipeTransform> | PipeTransform)[]
-) {
+): ParameterDecorator {
   return createGqlPipesParamDecorator(GqlParamtype.CONTEXT)(property, ...pipes);
 }

lib/decorators/directive.decorator.ts

@@ -0,0 +1,35 @@
+import { parse } from 'graphql';
+import { DirectiveParsingError } from '../schema-builder/errors/directive-parsing.error';
+import { TypeMetadataStorage } from '../schema-builder/storages/type-metadata.storage';
+
+/**
+ * Adds a directive to specified field, type, or handler.
+ */
+export function Directive(
+  sdl: string,
+): MethodDecorator & PropertyDecorator & ClassDecorator {
+  return (target: Function | Object, key?: string | symbol) => {
+    validateDirective(sdl);
+
+    if (key) {
+      TypeMetadataStorage.addDirectivePropertyMetadata({
+        target: target.constructor,
+        fieldName: key as string,
+        sdl,
+      });
+    } else {
+      TypeMetadataStorage.addDirectiveMetadata({
+        target: target as Function,
+        sdl,
+      });
+    }
+  };
+}
+
+function validateDirective(sdl: string) {
+  try {
+    parse(`type String ${sdl}`);
+  } catch (err) {
+    throw new DirectiveParsingError(sdl);
+  }
+}

lib/decorators/field.decorator.ts

@@ -0,0 +1,99 @@
+/**
+ * The API surface of this module has been heavily inspired by the "type-graphql" library (https://github.com/MichalLytek/type-graphql), originally designed & released by Michal Lytek.
+ * In the v6 major release of NestJS, we introduced the code-first approach as a compatibility layer between this package and the `@nestjs/graphql` module.
+ * Eventually, our team decided to reimplement all the features from scratch due to a lack of flexibility.
+ * To avoid numerous breaking changes, the public API is backward-compatible and may resemble "type-graphql".
+ */
+
+import { isFunction } from '@nestjs/common/utils/shared.utils';
+import { BaseTypeOptions } from '../interfaces/base-type-options.interface';
+import { ReturnTypeFunc } from '../interfaces/return-type-func.interface';
+import { TypeMetadataStorage } from '../schema-builder/storages/type-metadata.storage';
+import { reflectTypeFromMetadata } from '../utils/reflection.utilts';
+
+/**
+ * Interface defining options that can be passed to `@InputType()` decorator.
+ */
+export interface FieldOptions extends BaseTypeOptions {
+  /**
+   * Name of the field.
+   */
+  name?: string;
+  /**
+   * Description of the field.
+   */
+  description?: string;
+  /**
+   * Field deprecation reason (if deprecated).
+   */
+  deprecationReason?: string;
+}
+
+/**
+ * @Field() decorator is used to mark a specific class property as a GraphQL field.
+ * Only properties decorated with this decorator will be defined in the schema.
+ */
+export function Field(): PropertyDecorator & MethodDecorator;
+/**
+ * @Field() decorator is used to mark a specific class property as a GraphQL field.
+ * Only properties decorated with this decorator will be defined in the schema.
+ */
+export function Field(
+  options: FieldOptions,
+): PropertyDecorator & MethodDecorator;
+/**
+ * @Field() decorator is used to mark a specific class property as a GraphQL field.
+ * Only properties decorated with this decorator will be defined in the schema.
+ */
+export function Field(
+  returnTypeFunction?: ReturnTypeFunc,
+  options?: FieldOptions,
+): PropertyDecorator & MethodDecorator;
+/**
+ * @Field() decorator is used to mark a specific class property as a GraphQL field.
+ * Only properties decorated with this decorator will be defined in the schema.
+ */
+export function Field(
+  typeOrOptions?: ReturnTypeFunc | FieldOptions,
+  fieldOptions?: FieldOptions,
+): PropertyDecorator & MethodDecorator {
+  return (
+    prototype: Object,
+    propertyKey?: string,
+    descriptor?: TypedPropertyDescriptor<any>,
+  ) => {
+    const [typeFunc, options = {}] = isFunction(typeOrOptions)
+      ? [typeOrOptions, fieldOptions]
+      : [undefined, typeOrOptions as any];
+
+    const isResolver = !!descriptor;
+    const isResolverMethod = !!(descriptor && descriptor.value);
+
+    const { typeFn: getType, options: typeOptions } = reflectTypeFromMetadata({
+      metadataKey: isResolverMethod ? 'design:returntype' : 'design:type',
+      prototype,
+      propertyKey,
+      explicitTypeFn: typeFunc as ReturnTypeFunc,
+      typeOptions: options,
+    });
+
+    TypeMetadataStorage.addClassFieldMetadata({
+      name: propertyKey,
+      schemaName: options.name || propertyKey,
+      typeFn: getType,
+      options: typeOptions,
+      target: prototype.constructor,
+      description: options.description,
+      deprecationReason: options.deprecationReason,
+    });
+
+    if (isResolver) {
+      TypeMetadataStorage.addResolverPropertyMetadata({
+        kind: 'internal',
+        methodName: propertyKey,
+        schemaName: options.name || propertyKey,
+        target: prototype.constructor,
+      });
+    }
+  };
+}

lib/decorators/hide-field.decorator.ts

@@ -0,0 +1,5 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
+/* eslint-disable @typescript-eslint/no-empty-function */
+export function HideField(): PropertyDecorator {
+  return (target: Record<string, any>, propertyKey: string | symbol) => {};
+}

lib/decorators/index.ts

@@ -1,10 +1,17 @@
+export * from './args-type.decorator';
 export * from './args.decorator';
 export * from './context.decorator';
-export * from './delegate-property.decorator';
+export * from './directive.decorator';
+export * from './field.decorator';
+export * from './hide-field.decorator';
 export * from './info.decorator';
+export * from './input-type.decorator';
+export * from './interface-type.decorator';
 export * from './mutation.decorator';
+export * from './object-type.decorator';
 export * from './parent.decorator';
 export * from './query.decorator';
+export * from './resolve-field.decorator';
 export * from './resolve-property.decorator';
 export * from './resolve-reference.decorator';
 export * from './resolver.decorator';