[ISSUE] False positive "A scalar of type 'x' used as an array" issue messages

[menturion]

I am getting some false positive "A scalar of type 'x' used as an array" issue messages throughout the whole code.

The below example is a condensed example which results in a "A scalar of type 'null' used as an array" issue message for $vals['key02'].

You can test the sensitivity of the static analysis for this example, e.g. ...

• If you replace the value null in line $vals['key01'] = null; by an int value (e.g. '1') you will get "A scalar of type 'int' used as an array".
• If you remove line $vals['key01'] = $array['key01']; the issue message disappears.

function func(array $array): void
{
    $vals = [];

    if (!empty($array['key01'])) {
        $vals['key01'] = $array['key01'];
    } else {
        $vals['key01'] = null;
    }

    $vals['key02'] = [];
    if (!empty($array['key02'])) {
        $vals['key02'][] = $array['key02'];  // <-- Issue for $vals['key02']: "A scalar of type 'null' used as an array"
    }
}

[jakubmisek]

thank you for reporting that!

[jakubmisek]

issue fixed in the next update, thank you!

[menturion]

Good morning @jakubmisek

I have just tested it with v1.21.11048. The issue is fixed for the above given test scenario.

However, I still get issue messages of type "A scalar of type 'x' used as an array" for the below condensed code fragment.
In the below case a "A scalar of type 'int' used as an array" is shown for $vals['key02']:

function func(array $vals): void
{
    $vals['key01'] = 1;  // or e.g. 'test', null
    
    foreach ($vals['key02'] as $val) {  // <-- Issue for $vals['key02']: "A scalar of type 'int' used as an array"
        // No code required here for this test scenario
    }
}

[jakubmisek]

Thank you for the test case, we'll try to fix that!

[jakubmisek]

v1.21.11056 fixes that one! thank you, and please feel free to report any other false warning.

[menturion]

Many thanks.
The above test case is fixed by v1.21.11056.

Below is another test case:

function func(array $vals): void
{
    $vals['custom'] = 'custom';  // <-- Only sensitive to strings. The issue message disappears if int or null. 

    foreach ($vals['options'] as $options) {
        foreach ($options as $option) {  // <-- False positive for $options: A scalar of type 'string' used as an array PHP(PHP0409)
            // ...
        }

        $values = array_values($options);  // <-- False positive for $options: Argument '1' passed to array_values() is expected to be of type array, string givenPHP(PHP0406)
    }
}

[jakubmisek]

thank you! the last one is fixed in v1.21.11076. Please feel free to post any other test cases!

[menturion]

It seems to be fixed. Currently, I do not get any further issue messages of this kind.

[jakubmisek]

awesome! Thank you very much for your test cases.

[menturion]

Hi,

since the latest version 1.26.11866 (January 03, 2023) I am getting a huge number (> 200) of "A scalar of type 'x' used as an array" issues again.

Is this a regression?