Fix transforming and validating nested inputs and arrays

CHANGELOG.md

@@ -11,6 +11,7 @@
 - add basic support for directives with `@Directive()` decorator (#369)
 ### Fixes
 - refactor union types function syntax handling to prevent possible errors with circular refs
+- fix transforming and validating nested inputs and arrays (#462)
 
 ## v0.17.5
 ### Features

docs/validation.md

@@ -98,6 +98,8 @@ Note that by default, the `skipMissingProperties` setting of the `class-validato
 
 GraphQL will also check whether the fields have correct types (String, Int, Float, Boolean, etc.) so we don't have to use the `@IsOptional`, `@Allow`, `@IsString` or the `@IsInt` decorators at all!
 
+However, when using nested input or arrays, we always have to use [`@ValidateNested()` decorator](https://github.com/typestack/class-validator#validating-nested-objects) or [`{ each: true }` option](https://github.com/typestack/class-validator#validating-arrays) to make nested validation work properly.
+
 ## Response to the Client
 
 When a client sends incorrect data to the server:

src/helpers/types.ts

@@ -100,6 +100,10 @@ export function convertToType(Target: any, data?: object): object | undefined {
   if (data instanceof Target) {
     return data;
   }
+  // convert array to instances
+  if (Array.isArray(data)) {
+    return data.map(item => convertToType(Target, item));
+  }
 
   return Object.assign(new Target(), data);
 }

src/resolvers/convert-args.ts

@@ -0,0 +1,138 @@
+import { ArgParamMetadata, ClassMetadata, ArgsParamMetadata } from "../metadata/definitions";
+import { convertToType } from "../helpers/types";
+import { ArgsDictionary, ClassType } from "../interfaces";
+import { getMetadataStorage } from "../metadata/getMetadataStorage";
+import { TypeValue } from "../decorators/types";
+
+interface TransformationTreeField {
+  name: string;
+  target: TypeValue;
+  fields?: TransformationTree;
+}
+
+interface TransformationTree {
+  target: TypeValue;
+  getFields: () => TransformationTreeField[];
+}
+
+const generatedTrees = new Map<TypeValue, TransformationTree | null>();
+
+function getInputType(target: TypeValue): ClassMetadata | undefined {
+  return getMetadataStorage().inputTypes.find(t => t.target === target);
+}
+
+function getArgsType(target: TypeValue): ClassMetadata | undefined {
+  return getMetadataStorage().argumentTypes.find(t => t.target === target);
+}
+
+function generateInstanceTransformationTree(target: TypeValue): TransformationTree | null {
+  if (generatedTrees.has(target)) {
+    return generatedTrees.get(target)!;
+  }
+
+  const inputType = getInputType(target);
+  if (!inputType) {
+    generatedTrees.set(target, null);
+    return null;
+  }
+
+  function generateTransformationTree(metadata: ClassMetadata): TransformationTree {
+    let inputFields = metadata.fields!;
+    let superClass = Object.getPrototypeOf(metadata.target);
+    while (superClass.prototype !== undefined) {
+      const superInputType = getInputType(superClass);
+      if (superInputType) {
+        inputFields = [...inputFields, ...superInputType.fields!];
+      }
+      superClass = Object.getPrototypeOf(superClass);
+    }
+
+    const transformationTree: TransformationTree = {
+      target: metadata.target,
+      getFields: () =>
+        inputFields.map<TransformationTreeField>(field => {
+          const fieldTarget = field.getType();
+          const fieldInputType = getInputType(fieldTarget);
+          return {
+            name: field.name,
+            target: fieldTarget,
+            fields:
+              fieldTarget === metadata.target
+                ? transformationTree
+                : fieldInputType && generateTransformationTree(fieldInputType),
+          };
+        }),
+    };
+
+    return transformationTree;
+  }
+
+  const generatedTransformationTree = generateTransformationTree(inputType);
+  generatedTrees.set(target, generatedTransformationTree);
+  return generatedTransformationTree;
+}
+
+function convertToInput(tree: TransformationTree, data: any) {
+  const inputFields = tree.getFields().reduce<Record<string, any>>((fields, field) => {
+    const siblings = field.fields;
+    const value = data[field.name];
+    if (!siblings || !value) {
+      fields[field.name] = convertToType(field.target, value);
+    } else if (Array.isArray(value)) {
+      fields[field.name] = value.map(itemValue => convertToInput(siblings, itemValue));
+    } else {
+      fields[field.name] = convertToInput(siblings, value);
+    }
+    return fields;
+  }, {});
+
+  return convertToType(tree.target, inputFields);
+}
+
+function convertValueToInstance(target: TypeValue, value: any) {
+  const transformationTree = generateInstanceTransformationTree(target);
+  return transformationTree
+    ? convertToInput(transformationTree, value)
+    : convertToType(target, value);
+}
+
+function convertValuesToInstances(target: TypeValue, value: any) {
+  // skip converting undefined and null
+  if (value == null) {
+    return value;
+  }
+  if (Array.isArray(value)) {
+    return value.map(itemValue => convertValueToInstance(target, itemValue));
+  }
+  return convertValueToInstance(target, value);
+}
+
+export function convertArgsToInstance(argsMetadata: ArgsParamMetadata, args: ArgsDictionary) {
+  const ArgsClass = argsMetadata.getType() as ClassType;
+  const argsType = getArgsType(ArgsClass)!;
+
+  let argsFields = argsType.fields!;
+  let superClass = Object.getPrototypeOf(argsType.target);
+  while (superClass.prototype !== undefined) {
+    const superArgumentType = getArgsType(superClass);
+    if (superArgumentType) {
+      argsFields = [...argsFields, ...superArgumentType.fields!];
+    }
+    superClass = Object.getPrototypeOf(superClass);
+  }
+
+  const transformedFields = argsFields.reduce<Record<string, any>>((fields, field) => {
+    const fieldValue = args[field.name];
+    const fieldTarget = field.getType();
+    fields[field.name] = convertValuesToInstances(fieldTarget, fieldValue);
+    return fields;
+  }, {});
+
+  return convertToType(ArgsClass, transformedFields);
+}
+
+export function convertArgToInstance(argMetadata: ArgParamMetadata, args: ArgsDictionary) {
+  const argValue = args[argMetadata.name];
+  const argTarget = argMetadata.getType();
+  return convertValuesToInstances(argTarget, argValue);
+}

src/resolvers/helpers.ts

@@ -8,6 +8,7 @@ import { ResolverData, AuthChecker, AuthMode } from "../interfaces";
 import { Middleware, MiddlewareFn, MiddlewareClass } from "../interfaces/Middleware";
 import { IOCContainer } from "../utils/container";
 import { AuthMiddleware } from "../helpers/auth-middleware";
+import { convertArgsToInstance, convertArgToInstance } from "./convert-args";
 
 export async function getParams(
   params: ParamMetadata[],
@@ -22,13 +23,13 @@ export async function getParams(
         switch (paramInfo.kind) {
           case "args":
             return await validateArg(
-              convertToType(paramInfo.getType(), resolverData.args),
+              convertArgsToInstance(paramInfo, resolverData.args),
               globalValidate,
               paramInfo.validate,
             );
           case "arg":
             return await validateArg(
-              convertToType(paramInfo.getType(), resolverData.args[paramInfo.name]),
+              convertArgToInstance(paramInfo, resolverData.args),
               globalValidate,
               paramInfo.validate,
             );

src/resolvers/validate-arg.ts

@@ -23,7 +23,11 @@ export async function validateArg<T extends Object>(
 
   const { validateOrReject } = await import("class-validator");
   try {
-    await validateOrReject(arg, validatorOptions);
+    if (Array.isArray(arg)) {
+      await Promise.all(arg.map(argItem => validateOrReject(argItem, validatorOptions)));
+    } else {
+      await validateOrReject(arg, validatorOptions);
+    }
     return arg;
   } catch (err) {
     throw new ArgumentValidationError(err);

src/schema/schema-generator.ts

@@ -554,7 +554,7 @@ export abstract class SchemaGenerator {
         while (superClass.prototype !== undefined) {
           const superArgumentType = getMetadataStorage().argumentTypes.find(
             it => it.target === superClass,
-          )!;
+          );
           if (superArgumentType) {
             this.mapArgFields(superArgumentType, args);
           }