Skip to content

Example of assertion independence per awwright #771

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Aug 15, 2019
Merged

Example of assertion independence per awwright #771

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 29 additions & 2 deletions jsonschema-core.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -748,11 +748,38 @@
to the assertion.
</t>
<t>
For example, the "maxLength" keyword from the companion validation
vocabulary will only restrict certain strings
For example, the "maxLength" keyword from the companion
<xref target="json-schema-validation">validation vocabulary</xref>:
will only restrict certain strings
(that are too long) from being valid. If the instance is a number,
boolean, null, array, or object, then it is valid against this assertion.
</t>
<t>
This behavior allows keywords to be used more easily with instances
that can be of multiple primitive types. The companion validation
vocabulary also includes a "type" keyword which can independently
restrict the instance to one or more primitive types. This allows
for a concise expression of use cases such as a function that might
return either a string of a certain length or a null value:
</t>
<figure>
<artwork>
<![CDATA[
{
"type": ["string", "null"],
"maxLength": 255
}
]]>
</artwork>
<postamble>
If "maxLength" also restricted the instance type to be a string,
then this would be substantially more cumbersome to express because
the example as written would not actually allow null values.
Each keyword is evaluated separately unless explicitly specified
otherwise, so if "maxLength" restricted the instance to strings,
then including "null" in "type" would not have any useful effect.
</postamble>
</figure>
</section>
</section>

Expand Down