fix(repository): make the navigational property err msg more clear

[agnes512]

related #4392, stackoverflow

The belongsTo generator generates the default relation name by taking the @belongsTo decorated name then removing Id from it. Idealy, the default fk name is expected to be customerId, and the ideal relation name will be customer (code).

However, lots of users would come up with their own customized name, customer_id for example. And the default relation name generated by the belongsTo will be customer_id according to the code. This is problematic because in CRUD operations, it recognize customer_id as a navigational property instead of a model property. As a result, operations like

orderRepo.create({id: 1, name: 'LoopBack', customer_id: 1})

will be rejected with error 500 Error: Navigational properties are not allowed in model data.

Currently I couldn't find a good way to improve the way it generates the default relation name. So I am proposing to make the error message more clear and also update the site before we come up a better way for generating the default relation name.

Example new error message.
Navigational properties are not allowed in model data (model "Order" property "customer_id"). Please remove it or make sure the relation name is not the same as the property name in belongsTo relation.

Checklist

👉 Read and sign the CLA (Contributor License Agreement) 👈

• npm test passes on your machine
• New tests added or existing tests modified to cover all changes
• Code conforms with the style guide
• API Documentation in code was updated
• Documentation in /docs/site was updated
• Affected artifact templates in packages/cli were updated
• Affected example projects in examples/* were updated

👉 Check out how to submit a PR 👈

[bajtos]

Thank you for improving the error message ❤️

[bajtos]

This line is too long and difficult to review on GitHub. Please split it into multiple lines, e.g.

.to.be.rejectedWith(
  'Navigational properties are not allowed in model data (model "Customer" property "orders"). ' + 
    'Please remove it or make sure the relation name is not the same as the property name in belongsTo relation.',
);

(It's just an example, I am not sure if that's enough to keep the line length under 80 chars.)

The same comment applies to most other changed lines too.

[jannyHou]

Should it be belongsTo or hasMany?
Like Customer hasMany orders, IIUC the navigational property here is orders, which is the relation name for hasMany

[agnes512]

Yes,
For hasMany, orders would only be the navigational property. When you create a customer, you would do customerRepo.create({id: 1, name: 'customer'});

But for belongsTo, by how we defining the default relation name, the fk customer_id would have the default relation name as customer_id. When you do orderRepo.create({id: 1, des: 'order', customer_id: 1}), it recognizes the customer_id in the data as the relation name instead of the foreign key. That's why I state it clear that that the error might be caused by the nav property OR the naming issue here.

Please let me know if you have any suggestions to make it more intuitive.

[jannyHou]

@agnes512 👍 thank you got it. How about the following warning:

Navigational properties are not allowed in model data (model "${this.entityClass.modelName}" property "${relName}"), please remove it.
For relation belongsTo, please make sure the relation name is not the same as the property name.

[jannyHou]

nitpick: invalidName --> invalidNameMsg :-p

[jannyHou]

👏 LGTM