Prevent generation of invalid code for certain parameter default values

[loilo]

Certain default values for method parameters (strings containing single quotes or trailing backslashes) currently generate an invalid _ide_helper.php file.

This PR fixes that by replacing the current naïve code generation with a call to var_export().

[mfn]

Can you give an example how the code in practice looks like which triggers this?

I also think we should write tests for this

[loilo]

I agree. I have to admit that I was a little bit tired when I opened the PR and didn't have the patience to grasp the test structure of the repo. 😁

I encountered this problem when I made a facade for the loilo/x-filesystem package, the problem occurs with this method declaration (can be found here):

public function readCsvFile(
    string $filename,
    int $mode = self::PARSE_OBJECT,
    string $delimiter = ',',
    string $charset = 'UTF-8',
    string $enclosure = '"',   // <- If I change this to "'", it breaks as well
                               //    because it outputs '''
    string $escapeChar = '\\'  // <- This breaks because it outputs '\'
)

If you want me to, I can attach a minimal reproduction repo.

[loilo]

FWIW, I've added a test for these special characters in parameter default values.

[mfn]

Tanks, will take a look ASAP!

[mfn]

LGTM, also tested with a project "to be sure" 😄

[mfn]

ping @barryvdh