How can I add a property to the window object in Chrome using Applescript?

Question

In Chrome's JavaScript Console, I can type the following:

window.myVar = "myValue";

I can then access myVar from the window context, where it returns "myValue". Excellent.

However, if I do the following in Applescript:

tell application "Google Chrome"
    execute front window's active tab javascript "window.myVar = 'myValue';"
end tell

This execute statement appears to run when the script is called. No errors are thrown, and the Chrome window exists. But when I try to reference myVar from the window context, only undefined is ever returned. For testing purposes, I added in an alert statement after that declaration - the alert WILL fire, but myVar remains unset.

Now, in Safari, using do JavaScript with this same code works as if I'd typed the code directly into the console - myVar returns a value.

Why doesn't Chrome fire these statements when called by Applescript when it can be done manually? (Chrome 51.0.2704.84, OS X 10.11.5)

Answer 1

I discovered a workaround. Might not be the best, but the following line executes the JavaScript I have in mind while also setting properties of window:

tell front window of application "Google Chrome"
    set URL of active tab to "javascript:" & window.myVar = "myValue"
end tell

Using this, myVar properly returns "myValue". Nice.