Change in lettercase results in error

[slorenzbmw]

If i try to diff two files where only the following is different, i get the following error

Compare 1:
{ "name": "oneLine", "description": "***", "required": false, "in": "query", "type": "string" },
Compare 2:
{ "name": "online", "description": "***", "required": false, "in": "query", "type": "string" },
=> see the difference in "l" and "L" in the parameter "name"

Error:
Unexpected exception. Reason: Cannot invoke "String.isEmpty()" because "newParameterName" is null java.lang.NullPointerException: Cannot invoke "String.isEmpty()" because "newParameterName" is null at org.openapitools.openapidiff.core.compare.ParametersDiff.pathUnchangedParametersChanged(ParametersDiff.java:102) at org.openapitools.openapidiff.core.compare.ParametersDiff.diff(ParametersDiff.java:88) at org.openapitools.openapidiff.core.compare.OperationDiff.diff(OperationDiff.java:78) at org.openapitools.openapidiff.core.compare.PathDiff.diff(PathDiff.java:39) at org.openapitools.openapidiff.core.compare.PathsDiff.lambda$diff$3(PathsDiff.java:90) at java.base/java.util.LinkedHashMap$LinkedKeySet.forEach(LinkedHashMap.java:589) at org.openapitools.openapidiff.core.compare.PathsDiff.diff(PathsDiff.java:47) at org.openapitools.openapidiff.core.compare.OpenApiDiff.compare(OpenApiDiff.java:96) at org.openapitools.openapidiff.core.compare.OpenApiDiff.compare(OpenApiDiff.java:64) at org.openapitools.openapidiff.core.OpenApiCompare.fromSpecifications(OpenApiCompare.java:102) at org.openapitools.openapidiff.core.OpenApiCompare.fromLocations(OpenApiCompare.java:91) at org.openapitools.openapidiff.cli.Main.main(Main.java:175)

I can trace it back to here:

openapi-diff/core/src/main/java/org/openapitools/openapidiff/core/compare/ParametersDiff.java

Line 102 in d6383f3

if (newParameterName.isEmpty()) return false;

[joschi]

@slorenzbmw Thanks for reporting this!

I'm unable to reproduce your issue with a simple test:

--- core/src/test/resources/issue-495_1.yaml	2020-06-23 08:24:12
+++ core/src/test/resources/issue-495_2.yaml	2023-03-22 21:32:47
@@ -37,7 +37,7 @@
       description: Multiple status values can be provided with comma separated strings
       operationId: findPetsByStatus
       parameters:
-        - name: status
+        - name: Status
           in: query
           description: Status values that need to be considered for filter
           required: true

Could you please provide a minimal example to reproduce the issue?

[slorenzbmw]

Thanks for looking into this!
What i missed in my inital comment is that also a letter was added, but i could reproduce it both by changing the lettercase and removing / adding a letter to a parameter
i tested it on:

• Java Zulu 11
• Java Zulu 17

and could reproduce it with this minimum set:
old

{
  "swagger": "2.0",
  "info": {
    "title": "***",
    "version": "v1"
  },
  "host": "***",
  "basePath": "***",
  "schemes": [
    "https"
  ],
  "paths": {
    "/test": {
      "get": {
        "description": "***",
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "online",
            "description": "***",
            "required": false,
            "in": "query",
            "type": "string"
          }
        ]
      }
    }
  }
}

new

{
  "swagger": "2.0",
  "info": {
    "title": "***",
    "version": "v1"
  },
  "host": "***",
  "basePath": "***",
  "schemes": [
    "https"
  ],
  "paths": {
    "/test": {
      "get": {
        "description": "***",
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "oneLine",
            "description": "***",
            "required": false,
            "in": "query",
            "type": "string"
          }
        ]
      }
    }
  }
}

Any change on the parameter "name" results in a java.lang.NullPointerException for me