String operator STR_STARTS_WITH is not evaluated correctly when case-sensative is disabled

[wseibel]

Describe the bug

When using the STR_STARTS_WITH operator as a constraint on any context field with case-sensitive de-activated, the constraint is always evaluates to false.

Steps to reproduce the bug

Create an activation strategy for an enabled feature-toggle and update it with the following definition

curl --location --request PUT '<your-host>/api/admin/projects/<your-project>/features/test/environments/<your-environment>/strategies/<your-strategy-id>' \
    --header 'Authorization: INSERT_API_KEY' \
    --header 'Content-Type: application/json' \
    --data-raw '{
  "name": "flexibleRollout",
  "title": "",
  "constraints": [
    {
      "values": [
        "0"
      ],
      "inverted": false,
      "operator": "STR_STARTS_WITH",
      "contextName": "userId",
      "caseInsensitive": true
    }
  ],
  "parameters": {
    "rollout": "100",
    "stickiness": "default",
    "groupId": "test"
  },
  "variants": [
    {
      "stickiness": "default",
      "name": "a",
      "weight": 1000,
      "payload": {
        "type": "string",
        "value": "a"
      },
      "weightType": "variable"
    }
  ],
  "segments": [],
  "disabled": false
}'

Now evaluate the feature toggle you updated the strategy for with any user-id that starts with "0".
The result is "disabled".

Expected behavior

The evaluation result should return the variation with the name "a".

Logs, error output, etc.

No response

Screenshots

No response

Additional context

When looking into the code the error is easy to spot

return contextValue
                .map(
                        c ->
                                values.stream()
                                        .anyMatch(
                                                v -> {
                                                    if (caseInsensitive) {
                                                        return v.toLowerCase(comparisonLocale) // <-- v.startsWith should be c.startsWith
                                                                .startsWith(
                                                                        c.toLowerCase(
                                                                                comparisonLocale));
                                                    } else {
                                                        return c.startsWith(v); // <-- this is correct
                                                    }
                                                }))
                .orElse(false);

The comparison is the wrong way around as can be seen in the else-branch or any other method in this class, where it's done correctly.

Unleash version

No response

Subscription type

None

Hosting type

None

SDK information (language and version)

unleash-client-java:9.2.0

[rishiraj88]

Very apt catch, @wseibel .

// if-clause checks v.startsWith(c)
if (caseInsensitive) {return v.toLowerCase(..).startsWith(c.toLowerCase(..));
}else {// else-clause checks c.startsWith(v) (as opposite of the if-clause check!!)
return c.startsWith(v); // <-- this is correct
}

It is obvious to fix.

[rishiraj88]

I think v and c both need to be interchanged in if clause.
What do you think, @wseibel ?

[wseibel]

@rishiraj88 thanks for the quick reply. You're absolutely right.

[chriswk]

A big thanks to both of you, great report, I'll get a fix out, and add a test so we catch it if it happens again.

[chriswk]

Handled in #240

[chriswk]

Added in 9.2.1, should be synced to most mirrors by now. This https://repo1.maven.org/maven2/io/getunleash/unleash-client-java/9.2.1/ is at least present on central