Resolve uri references in remote schemas against those schemas' base uris

[Foxcapades]

Problem

Presently when resolving a remote schema, uri-references within that schema are not correctly resolved against the base uri of the original reference.

For example, my schema references https://json-schema.org/draft/2020-12/schema which in turn references meta/core. The current result is a joined path of

/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core

which doesn't exist, and in turn results in an incomplete doc, and the following output:

WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/applicator: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/applicator'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/applicator
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/unevaluated: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/unevaluated'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/unevaluated
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/meta-data: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/meta-data'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/meta-data
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/format-annotation: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/format-annotation'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/format-annotation
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/content: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/content'
WARNING:root:Path __root__ not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/content
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation'
WARNING:root:Path $defs/stringArray not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation
WARNING:root:Path $defs/stringArray not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/validation
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core'
WARNING:root:Path $defs/anchorString not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core
WARNING:root:Path $defs/anchorString not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core
WARNING:root:Error loading schema from uri /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core: [Errno 2] No such file or directory: '/home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core'
WARNING:root:Path $defs/uriReferenceString not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core
WARNING:root:Path $defs/uriReferenceString not found in schema at URI /home/me/my-project/https:/json-schema.org/draft/2020-12/meta/core

Fix

Before attempting to join the paths using os.path.join as a filesystem path, test if the current file is from a remote URL, and if so, resolve the uri_part as a URL path instead.

Testing

From local testing this has resolved the errors I was getting, and the docs render correctly. Additionally I ran the poetry run pytest tests command from the contributing doc.