[Downgrade PHP 8.0] Throw expression

[leoloso]

Feature Request

Downgrade new feature from PHP 8.0 to its equivalent PHP 7.4 code. RFC with explanation

We must identify all the different places where throw can appear as an expression, and transform each of them to a statement.

If when executing the rule the code contains an unhandled example, it should throw a DowngradeNotImplementedException (and not a DowngradeNotPossibleException), asking the developer to report the code as a new issue in Rector, so it can be implemented.

From the RFC, the following examples have been identified. What others are there?

Diff

// This was previously not possible since arrow functions only accept a single expression while throw was a statement.
-$callable = fn() => throw new Exception();
+$callable = function() {
+    throw new Exception()
+};
 
// $value is non-nullable.
-$value = $nullableValue ?? throw new InvalidArgumentException();
+if ($nullableValue !== null) {
+    $value = $nullableValue;
+} else {
+    throw new InvalidArgumentException();
+}
 
// $value is truthy.
-$value = $falsableValue ?: throw new InvalidArgumentException();
+if ($falsableValue) {
+    $value = $falsableValue;
+} else {
+    throw new InvalidArgumentException();
+}
 
// $value is only set if the array is not empty.
-$value = !empty($array)
-    ? reset($array)
-    : throw new InvalidArgumentException();
+if (!empty($array)) {
+    $value = reset($array);
+} else {
+    throw new InvalidArgumentException();
+}

[TomasVotruba]

I'm on it

[TomasVotruba]

It's way more complicated then I expected. I'm giving up for other priorities

[TomasVotruba]

Closing as PHP 8.0 is not a version we need to downgrade now. Let's handle in the future, when issues will pop :)