[FEATURE] Conditional Validation

Summary:

Would love if there was a way to run validation on an attribute if a different attribute is set to a specific value.

Code sample:

General

In a different package(https://github.com/clarkie/dynogels) that i’m using, it uses Joi where I can do this…

age: Joi.when('application_id', { is: 'foo', then: Joi.string().trim().required(), })

So this attribute is only required if application_id is set to foo. Doesn’t necessarily have to use Joi, thats just what that other package uses.

QA Discussion

Other:

• I have read through the Dynamoose documentation before posting this issue
• I have searched through the GitHub issues (including closed issues) and pull requests to ensure this feature has not already been suggested before
• I have filled out all fields above
• I am running the latest version of Dynamoose

[fishcharlie]

So based on my last comment.

Implement a validate method on the Schema itself

This is done, and will be included in the next v3 release (by the end of this weekend at the latest, if a new release hasn’t been released by the end of the weekend please remind me to do so).

Additionally (and kinda unrelated), there is support for get and set modifiers on the schema settings itself.

this will be a function that the item/document is passed into, or potentially an array of functions

This is a function that the item object is passed into. It does not currently accept an array of functions. If someone believes having an array of functions would be valuable, please create a new feature request issue for this.

Add support for plugins #851

Sadly, I have no idea if this is going to make it into v3. It’s really hard to say at this point.

dynamoose would build and maintain plugins for Joi support

See above. This is even less likely at this point.

---

Example:

const schema = new dynamoose.Schema({
	"id": String,
	"name": String
}, {
	"validate": (obj) => {
		if (!obj.id.beginsWith(name[0])) {
			throw new Error("id first letter of name.");
		}

		return true;
	}
});

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So the short version: This is now possible. But not quite as seamless as it would be if Dynamoose had a Joi plugin.

So I will be closing this issue.

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Disclaimer: I still have not used Joi before. Would appreciate someone testing out this new functionality to see if they can get it working, and report back if it’s successful or if the API needs to be changed or can be improved to better fit Joi validation.

[fishcharlie]

After thinking about this a bit more. This seems like it’d be a good plugin for Dynamoose. In v3 I’m planning to explore basic plugin support.

In v3 I will either develop a plugin to support Joi validation, or support Joi validation natively.

Might also be interesting to explore having a validate function on the schema itself. That way you can validate the entire item and ensure the entire item is what you expect.