Following a NestJS tutorial, I encountered something that drew my attention (coming from a service.ts file):
public async putCarById(id: number, property_name: string, property_value: string)// : Promise<any>
{
console.log(id); // gives provided number, for example, 1
const carId = Number(id);
console.log(typeof (id)); // will output "string" - why ?
console.log(typeof (carId)); // will output "number" -- which I understand
(...)
I could not find why it was necessary to do the "cast" while id was supposed to be received as a number.
Related
I have this code
#Get()
#ApiQuery({
name: "code",
type: String,
required: false,
})
#ApiQuery({
name: "id",
type: Number,
required: false,
})
async read(
#Query("entity") entity: string,
#Query("code") code: string,
#Query("id", ParseIntPipe) id: number
): Promise<Q> {
return this.service.readAsync({ where: { codigo: code, id: id } });
}
Why I'm getting Validation failed (numeric string is expected) when I request to http://localhost:3000/api/v1/endpoint?entity=a&code=b
I know is related with id param, but I don't know how to solve this.
I want to be able to use code or id params according my needs.
If I request to http://localhost:3000/api/v1/endpoint?entity=a&code=b&id=1 or http://localhost:3000/api/v1/endpoint?entity=a&id=1 all is fine.
here #Query("id", ParseIntPipe) id: number you're saying that the query parameter id is required and must be an integer.
Thus, if you do GET /endpoint?entity=a&code=b, it will reply with bad request as there's no id parameter.
You can use the DefaultValuePipe pipe if id should be optional and will have a fallback value.
If you don't want any default value, then you'll need to write your own pipe (that could extends ParseIntPipe). Or you could use the builtin one ValidationPipe with class-validator decorators.
ParserIntPipe doesn't work on optional parameters, from its source code, you can see
async transform(value: string, metadata: ArgumentMetadata): Promise<number> {
if (!this.isNumeric(value)) {
throw this.exceptionFactory(
'Validation failed (numeric string is expected)',
);
}
return parseInt(value, 10);
}
/**
* #returns `true` if `value` is a valid integer number
*/
protected isNumeric(value: string): boolean {
return (
['string', 'number'].includes(typeof value) &&
/^-?\d+$/.test(value) &&
isFinite(value as any)
);
}
As per Micael Levi answer, you either provide a default value using DefaultValuePipe in case it was missing, or you build your own custom pipe that pass parameter undefined value
Am playing around with Typescript, Mongoose, NodeJS and Express, using the sample MongoDB data based on restaurants.
Am attempting to create simple CRUD operations, with the intent on returning All restaurants, then a specific restaurant and eventually filter/sort etc.
See the function below:
const fetchRestaurants = async (request: Request, response: Response): Promise<RestaurantInterface[]> => {
try {
const restaurants: RestaurantInterface[] = await RestaurantModel.find();
response.status(200).json({
restaurants
});
} catch (error) {
throw error;
}
}
If I remove this line Promise<RestaurantInteface[] (or switch strict: false) I have no issues otherwise it alternates between.
A function whose declared type is neither 'void' nor 'any' must return a value.ts(2355) and if I attempt to return the response Type 'Response<any, Record<string, any>>' is missing the following properties from type 'RestaurantInterface[]': length, pop, push, concat, and 26 more.ts(2740)
Do I have basically loosen up the ts compiler or is there something I've misunderstood?
// in another file
export interface RestaurantInterface {
name: string,
borough: string,
cuisine: string,
restaurant_id: string
address: Address,
grades: Grades[],
};
Well it is expected, because the function actually returns void. When you write function name(): Promise<...> it means that you should return something. Whereas you are just calling the json method of the Express. So it is expected.
I've made simple CRUD app with React and Apollo client on NestJS server with GraphQL API.
I have this simple Mutations:
schema.gql:
type Mutation {
createUser(input: CreateUserInput!): User! // CreateUserInput type you can see in user.input.ts below
updateUser(id: ID!, input: UpdateUserInput!): User!
deleteUser(id: ID!): User!
}
user.input.ts:
import { InputType, Field } from "#nestjs/graphql";
import { EmailScalar } from "../email.scalar-type";
#InputType()
export class CreateUserInput {
// EmailScalar is a custom Scalar GraphQL Type that i took from the internet and it worked well
#Field(() => EmailScalar)
readonly email: string;
#Field()
readonly name: string;
}
"EmailScalar" type checks if "email" input has *#*.* format basically
And when i make createUser Query to GraphQL API like this:
It cannot pass validation
(because Email type works fine)
But when Query sent from client - it passes validation:
NestJS server log (from code below)
users.resolver.ts:
#Mutation(() => User)
async createUser(#Args('input') input: CreateUserInput) { // Type from user.input.ts
Logger.log(input); // log from screenshot, so if it's here it passed validation
return this.usersService.create(input); // usersService makes requests to MongoDB
}
And it gets into MongoDB
Here is client side part:
App.tsx:
...
// CreateUserInput class is not imported to App.tsx (it is at server part) but it seems to be fine with it
const ADD_USER = gql`
mutation AddMutation($input: CreateUserInput!) {
createUser(input: $input) {
id
name
email
}
}
`
function App(props: any) {
const { loading, error, data } = useQuery(GET_USERS);
const [addUser] = useMutation(
ADD_USER,
{
update: (cache: any, { data: { createUser } }: any) => {
const { users } = cache.readQuery({ query: GET_USERS });
cache.writeQuery({
query: GET_USERS,
data: {
users: [createUser, ...users],
},
})
}
}
);
...
if (loading) return <p>Loading...</p>;
if (error) return <p>Error :(</p>;
return <UserTable users={data.users} addUser={addUser} updateUser={updateUser} deleteUser={deleteUser} />;
}
Can someone please explain to me, how does client Query passes validation and what have i done wrong?
Even two empty strings can pass through.
Never worked with NestJS, Apollo, React or GraphQL before, so I'm kinda lost.
For full code:
https://github.com/N238635/nest-react-crud-test
This is how your custom scalar's methods are defined:
parseValue(value: string): string {
return value;
}
serialize(value: string): string {
return value;
}
parseLiteral(ast: ValueNode): string {
if (ast.kind !== Kind.STRING) {
throw new GraphQLError('Query error: Can only parse strings got a: ' + ast.kind, [ast]);
}
// Regex taken from: http://stackoverflow.com/a/46181/761555
var re = /^([\w-]+(?:\.[\w-]+)*)#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
if (!re.test(ast.value)) {
throw new GraphQLError('Query error: Not a valid Email', [ast]);
}
return ast.value;
}
parseLiteral is called when parsing literal values inside the query (i.e. literal strings wrapped in double quotes). parseValue is called when parsing variable values. When your client sends the query, it sends the value as a variable, not as a literal value. So parseValue is used instead of parseLiteral. But your parseValue does not do any kind of validation -- you just return the value as-is. You need to implement the validation logic in both methods.
It would also be a good idea to implement the serialize method so that your scalar can be used for both input and response validation.
I define a schema like this:
const query = new GraphQLObjectType({
name: 'Query',
fields: {
quote: {
type: queryType,
args: {
id: { type: QueryID }
},
},
},
});
const schema = new GraphQLSchema({
query,
});
The QueryID is a customised scalar type.
const QueryID = new GraphQLScalarType({
name: 'QueryID',
description: 'query id field',
serialize(dt) {
// value sent to the client
return dt;
},
parseLiteral(ast) {
if (ast.kind === 'IntValue') {
return Number(ast.value);
}
return null;
},
parseValue(v) {
// value from the client
return v;
},
});
client query
query {
quote(queryType: 1)
}
I found that the parseValue method is not called when clients send query to my server. I can see parseLiteral is called correctly.
In most of the document I can find, they use gql to define schema and they need to put scalar QueryID in their schema definition. But in my case, I am using GraphQLSchema object for schema. Is this the root cause of that? If yes, what is the best way to make it works? I don't want to switch to gql format because I need to construct my schema at runtime.
serialize is only called when sending the scalar back to the client in the response. The value it receives as a parameter is the value returned in the resolver (or if the resolver returned a Promise, the value the Promise resolved to).
parseLiteral is only called when parsing a literal value in a query. Literal values include strings ("foo"), numbers (42), booleans (true) and null. The value the method receives as a parameter is the AST representation of this literal value.
parseValue is only called when parsing a variable value in a query. In this case, the method receives as a parameter the relevant JSON value from the variables object submitted along with the query.
So, assuming a schema like this:
type Query {
someField(someArg: CustomScalar): String
someOtherField: CustomScalar
}
serialize:
query {
someOtherField: CustomScalar
}
parseLiteral:
query {
someField(someArg: "something")
}
parseValue:
query ($myVariable: CustomScalar) {
someField(someArg: $myVariable)
}
In an update to our GraphQL API only the models _id field is required hence the ! in the below SDL language code. Other fields such as name don't have to be included on an update but also cannot have null value. Currently, excluding the ! from the name field allows the end user to not have to pass a name in an update but it allows them to pass a null value for the name in, which cannot be allowed.
A null value lets us know that a field needs to be removed from the database.
Below is an example of a model where this would cause a problem - the Name custom scalar doesn't allow null values but GraphQL still allows them through:
type language {
_id: ObjectId
iso: Language_ISO
auto_translate: Boolean
name: Name
updated_at: Date_time
created_at: Date_time
}
input language_create {
iso: Language_ISO!
auto_translate: Boolean
name: Name!
}
input language_update {
_id: ObjectId!
iso: Language_ISO!
auto_translate: Boolean
name: Name
}
When a null value is passed in it bypasses our Scalars so we cannot throw a user input validation error if null isn't an allowed value.
I am aware that ! means non-nullable and that the lack of the ! means the field is nullable however it is frustrating that, as far as I can see, we cannot specify the exact values for a field if a field is not required / optional. This issue only occurs on updates.
Are there any ways to work around this issue through custom Scalars without having to start hardcoding logic into each update resolver which seems cumbersome?
EXAMPLE MUTATION THAT SHOULD FAIL
mutation tests_language_create( $input: language_update! ) { language_update( input: $input ) { name }}
Variables
input: {
_id: "1234",
name: null
}
UPDATE 9/11/18: for reference, I can't find a way around this as there are issues with using custom scalars, custom directives and validation rules. I've opened an issue on GitHub here: https://github.com/apollographql/apollo-server/issues/1942
What you're effectively looking for is custom validation logic. You can add any validation rules you want on top of the "default" set that is normally included when you build a schema. Here's a rough example of how to add a rule that checks for null values on specific types or scalars when they are used as arguments:
const { specifiedRules } = require('graphql/validation')
const { GraphQLError } = require('graphql/error')
const typesToValidate = ['Foo', 'Bar']
// This returns a "Visitor" whose properties get called for
// each node in the document that matches the property's name
function CustomInputFieldsNonNull(context) {
return {
Argument(node) {
const argDef = context.getArgument();
const checkType = typesToValidate.includes(argDef.astNode.type.name.value)
if (checkType && node.value.kind === 'NullValue') {
context.reportError(
new GraphQLError(
`Type ${argDef.astNode.type.name.value} cannot be null`,
node,
),
)
}
},
}
}
// We're going to override the validation rules, so we want to grab
// the existing set of rules and just add on to it
const validationRules = specifiedRules.concat(CustomInputFieldsNonNull)
const server = new ApolloServer({
typeDefs,
resolvers,
validationRules,
})
EDIT: The above only works if you're not using variables, which isn't going to be very helpful in most cases. As a workaround, I was able to utilize a FIELD_DEFINITION directive to achieve the desired behavior. There's probably a number of ways you could approach this, but here's a basic example:
class NonNullInputDirective extends SchemaDirectiveVisitor {
visitFieldDefinition(field) {
const { resolve = defaultFieldResolver } = field
const { args: { paths } } = this
field.resolve = async function (...resolverArgs) {
const fieldArgs = resolverArgs[1]
for (const path of paths) {
if (_.get(fieldArgs, path) === null) {
throw new Error(`${path} cannot be null`)
}
}
return resolve.apply(this, resolverArgs)
}
}
}
Then in your schema:
directive #nonNullInput(paths: [String!]!) on FIELD_DEFINITION
input FooInput {
foo: String
bar: String
}
type Query {
foo (input: FooInput!): String #nonNullInput(paths: ["input.foo"])
}
Assuming that the "non null" input fields are the same each time the input is used in the schema, you could map each input's name to an array of field names that should be validated. So you could do something like this as well:
const nonNullFieldMap = {
FooInput: ['foo'],
}
class NonNullInputDirective extends SchemaDirectiveVisitor {
visitFieldDefinition(field) {
const { resolve = defaultFieldResolver } = field
const visitedTypeArgs = this.visitedType.args
field.resolve = async function (...resolverArgs) {
const fieldArgs = resolverArgs[1]
visitedTypeArgs.forEach(arg => {
const argType = arg.type.toString().replace("!", "")
const nonNullFields = nonNullFieldMap[argType]
nonNullFields.forEach(nonNullField => {
const path = `${arg.name}.${nonNullField}`
if (_.get(fieldArgs, path) === null) {
throw new Error(`${path} cannot be null`)
}
})
})
return resolve.apply(this, resolverArgs)
}
}
}
And then in your schema:
directive #nonNullInput on FIELD_DEFINITION
type Query {
foo (input: FooInput!): String #nonNullInput
}