fix(analytics): validate against incomplete/invalid app_remove events

[cabljac]

This draft PR is a proposed solution to resolve #1712

Problem

When an analytics event payload contains malformed user properties, the SDK throws a TypeError before the user's callback can execute:

// Problematic payloads:
userProperties: {
  "some_property": null,                    // Entirely null
  "another_property": { "value": null },    // Value field is null
  "empty_property": {}                      // Missing value field
}

Error:

TypeError: Cannot convert undefined or null to object
at Function.keys ()
at unwrapValueAsString (analytics.js:206)

Solution

1. Made unwrapValueAsString defensive

• Added null/undefined/empty object checks before calling Object.keys()
• Returns empty string for invalid inputs instead of throwing
• Improved type safety by changing parameter from any to unknown

2. Filter invalid user properties

• Added filter in UserDimensions constructor to skip properties that are:
  • null or undefined
  • Empty objects {}
  • Objects with value field that is null, undefined, or {}
• Valid properties (including falsy values like "" and 0) are preserved

[taeold]

/gemini review

[gemini-code-assist]

Code Review

This pull request provides a solid fix for a crash caused by malformed user properties in analytics events. The approach is robust, adding defensive checks in unwrapValueAsString and filtering invalid properties during event construction. The addition of a new test case that covers various invalid inputs is excellent for ensuring correctness and preventing future regressions. I have one suggestion to improve the readability of the new filtering logic.

[gemini-code-assist]

The filtering logic here is comprehensive but also quite complex and spread across multiple conditional statements, which could affect readability and future maintenance. To make the logic clearer and more self-documenting, you could refactor it slightly by grouping related checks and adding comments to explain each validation step.

        .filter(([, v]) => {
          // Property must be a non-empty object.
          if (v == null || typeof v !== "object") {
            return false;
          }
          if (Object.keys(v).length === 0) {
            return false;
          }

          // If 'value' field exists, it must not be null, undefined, or an empty object.
          if ("value" in v) {
            const value = (v as { value: unknown }).value;
            if (value == null || (typeof value === "object" && value !== null && Object.keys(value).length === 0)) {
              return false;
            }
          }

          return true;
        })