UI crashes on complex OpenAPI documents

[pavelkornev]

Q&A (please complete the following information)

• OS: macOS, Windows
• Browser: Chrome
• Version: 120.0.6099.234
• Method of installation: web version - https://editor-next.swagger.io/
• Swagger-UI version: n/a
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

When rendering a complex OpenAPI document, UI comes unresponsive first with the following browser dialog, and eventually crashes later:

Example Swagger/OpenAPI definition:
https://api.sap.com/odata/1.0/catalog.svc/APIContent.APIs('SAP_ICSM_StudyService')/$value?type=json

Describe the bug you're encountering

To reproduce...

Steps to reproduce the behavior:

1. Go to https://editor-next.swagger.io/
2. Paste content from this link: https://api.sap.com/odata/1.0/catalog.svc/APIContent.APIs('SAP_ICSM_StudyService')/$value?type=json
3. Try to expand first operation "/BlindingGroups"

Expected behavior

UI doesn't crash.

[Coder-Manuel]

Am also experiencing the same, Any fix/walk-around ?

UPDATE: 13th Feb 2024
Walk-around is to downgrade to v7.1.0

[char0n]

I can confirm. This is very reproducible.

[glowcloud]

Investigating this issue within Swagger Client, I found out that the resolve mechanism executes for a long time due to the complexity of the specification with the nested references. The specification should eventually be resolved but the operations take too long. Because of this SwaggerUI will freeze.

I tried breaking out of the traversal early by creating and setting a maximum count of it to a 1000 for each run of the plugins. I broke out of the execution here https://github.com/swagger-api/swagger-js/blob/f00b527fd71f46ccf1a4ae14853edc5452160b04/src/specmap/index.js#L108 and here https://github.com/swagger-api/swagger-js/blob/f00b527fd71f46ccf1a4ae14853edc5452160b04/src/specmap/index.js#L137 if the limit was reached. This allowed the specification to be partially resolved and loaded in SwaggerUI, although rendering slowly. Unfortunately, as we don’t resolve everything, components looked like this:

The missing values are unresolved, for example scenario from the second image is:

{
  allOf: [
    {
      '$ref': '#/components/schemas/com.sap.ctsm.backend.core.api.study.v1.StudyAPIv1.Scenarios-create'
    }
  ],
  nullable: true
}

and kitTypeAssignments:

{
    type: 'array',
    items: {
      '$ref': '#/components/schemas/com.sap.ctsm.backend.core.api.study.v1.StudyAPIv1.KitTypeTreatmentAssignments-create'
    }
  }

Perhaps we could render these unresolved definitions with reference strings but resolving everything is not possible at the moment.

[glowcloud]

The crashing issue was addressed in swagger-api/swagger-js#3380, released as https://github.com/swagger-api/swagger-js/releases/tag/v3.25.3.

As it turned out, the complex specification was being eventually resolved, but the operations took too long due to the nested definitions. To fix this, we limited the maximum traversal depth for each run of the plugins. This allows us to get a partially resolved specification, which has to be resolved further in Swagger UI.
A fix was also added for the limit of the plugins dispatch runs, which now correctly tracks each plugin separately.

[glowcloud]

Rendering schemas not resolved by Swagger Client addressed in #9629.

[pavelkornev]

This still fails on the original example given in the issue description.

Steps:

1. Go to https://editor-next.swagger.io/
2. Paste content from this link: https://api.sap.com/odata/1.0/catalog.svc/APIContent.APIs('SAP_ICSM_StudyService')/$value?type=json
3. Expand first operation "/BlindingGroups"
4. Collapse the expanded operation "/BlindingGroups"
5. Expand second operation "/BlindingGroups({ID})" -> crash!

Please reopen the issue!