REST Support for null column values in request body added

[ayush3797]

Why is this change being made?

The code changes are meant to add support for assigning NULL value to columns for REST operations like POST,PUT,PATCH.

What changed?

1. Added checks which prevent assignment of NULL value to non-nullable columns in different REST operations.2.

2. Removed the code which used to throw an error whenever a NULL value was assigned to a column in the request body irrespective of whether the column was nullable or not.

How was this validated?

1. Added positive test cases for INSERT/PUT/PATCH operations having NULL value assigned to the columns that were nullable.

2. Added negative test cases for INSERT/PUT/PATCH operations having NULL value assigned to the columns that were non-nullable.

[seantleonard]

Some comments about breaking out Nullable Tests into their own test methods.

[Aniruddh25]

Waiting on making function arguments nullable

[Aniruddh25]

Please resolve all comments. If you think you have resolved them, mark them as such - so reviewers can verify and close.

[gledis69]

We should be careful with using IsNullOrWhitespace in the request validator, since some conditionals use that to determine invalid column values, but it will raise errors for empty strings which are be valid input for text columns.

They should be switched to null checks.

[ayush3797]

We should be careful with using IsNullOrWhitespace in the request validator, since some conditionals use that to determine invalid column values, but it will raise errors for empty strings which are be valid input for text columns.

They should be switched to null checks.

So empty string i.e. "" is a valid value ? I thought its invalid.

[Aniruddh25]

We should be careful with using IsNullOrWhitespace in the request validator, since some conditionals use that to determine invalid column values, but it will raise errors for empty strings which are be valid input for text columns.
They should be switched to null checks.

So empty string i.e. "" is a valid value ? I thought its invalid.

Good point @gledis69, empty or white space are VALID inputs to string columns.

[ayush3797]

@gledis69 , your concern has been addressed.

[Aniruddh25]

Need test cases for empty string

[Aniruddh25]

Do we have a test case for the null or white space field value? If not, could you please add one, if not added already...

[ayush3797]

We do have for null values. Want me to add for white space field value?

[Aniruddh25]

yes, white space or empty string please.

[Aniruddh25]

LGTM after resolving merge conflicts and adding test for empty string.