Fix TypeError when receiving messages without action property

[ErkoRisthein]

Summary

Fixes TypeError: Cannot read properties of undefined (reading 'startsWith') that occurs when the window receives postMessage events that have a data property but no action property.

Root Cause

The condition event.data?.action.startsWith("web-eid:") safely handles when event.data is undefined, but throws when event.data exists and event.data.action is undefined.

Fix

Add optional chaining on action:

if (!event.data?.action?.startsWith("web-eid:")) return;

Test Plan

• Added unit tests for messages with missing action property
• npm test passes (48 tests)

Signed-off-by: Erko Risthein erko@risthein.ee

[Copilot]

Pull request overview

This PR fixes a TypeError that occurs when the window receives postMessage events with a data property but without an action property. The fix adds optional chaining to safely access the action property before calling startsWith().

Key Changes:

• Added optional chaining operator to prevent TypeError when event.data.action is undefined
• Added unit tests to verify messages without the action property are properly ignored

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/services/WebExtensionService.ts	Added optional chaining to event.data.action to prevent TypeError when action is undefined
src/services/tests/WebExtensionService-test.ts	Added three test cases verifying that messages with missing/null/undefined data or action properties are properly ignored

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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