“Pharaoh let the people go. The shortest road from Goshen to Canaan went through the Philistine country. But God didn’t lead them that way. God said, ‘If they have to go into battle, they might change their minds. They might return to Egypt.’” Exodus 13:17

You could read this and wonder-if? They might? Did God already know what choice they would make, so in essence, didn’t give them the opportunity to make it?

“God left him {Hezekiah} alone only to test him, that He might know all that was in his heart.” 2 Chron. 32:31
There are a lot of examples in the O.T. where God did things to test the kings. He tests, they humble themselves/repent, and God forgives. And then the cycle often begins again. There is always sin.
I often wonder how much of the Old Testament we “miss” or just misunderstand. How much is lost in translation from the original languages-Latin, Greek, Arabic, Hebrew, whatever they all are :-) See it says here He wants to see what was in his heart? Doesn’t God already know what’s in our hearts? Was He testing Hezekiah so HEZEKIAH would know what was in his own heart?

Duet. 8:16b says “…to humble and to test you so that in the end it might go well with you.”
Isaiah 38 is one of the accounts of Hezekiah’s illness (2 Kings 20 is another). It says Hezekiah wrote verses nine to twenty. In Verse 17 he says, “Surely it was for my benefit that I suffered such anguish.” He then goes on to praise God because of what He did.
This is one of those places where I wish I could just say scholars-tell me what the meaning is! But there may be two or three more interpretations! A Jewish commentary would be especially handy as they bring in the traditions, the language, and the culture. But still, I don’t know that we ever fully grasp what it meant to the Israelites.