8

I have an api that in the past developments would receive comma separated strings as valid input and used the following as the validator: Joi.string()

But now I want to implement the same variable using array of strings as mentioned here https://github.com/glennjones/hapi-swagger/issues/119. So the new check would be:

Joi.array().items(Joi.string())

But I do not want to break the backward compatibility of the code. Is there a way to check both conditions for the variable?

I am a newbie to Joi, so any help or guidance would be appreciated. Thanks in advance.

Jasjeet Kaur
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2 Answers2

16

Take a look at .alternatives().try() which supports multiple schemas for a single field.

For example:

Joi.alternatives().try(Joi.array().items(Joi.string()), Joi.string())

This will validate both arrays of strings and plain strings, however as I'm sure you know, you'll still need server side logic to check which format the value is so you can process it properly.

Ankh
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5

You can use alternatives.try or shorthand [schema1, schema2]

const Joi = require('joi');

const schema1 = {
    param: Joi.alternatives().try(Joi.array().items(Joi.string()), Joi.string())
};

const result1 = Joi.validate({param: 'str1,str2'}, schema1);
console.log(result1.error); // null

const result2 = Joi.validate({param: ['str1', 'str2']}, schema1);
console.log(result2.error); // null


const schema2 = {
    param: [Joi.array().items(Joi.string()), Joi.string()]
};

const result3 = Joi.validate({param: 'str1,str2'}, schema2);
console.log(result3.error); // null

const result4 = Joi.validate({param: ['str1', 'str2']}, schema2);
console.log(result4.error); // null
gump
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