Improve error messages for shape and vec -like types

[vrielsa]

Given:

use Psl\Type;
$shape = Type\shape([
    'name' => Type\string(),
    'articles' => Type\vec(Type\shape([
        'title' => Type\string(),
        'content' => Type\string(),
        'likes' => Type\int(),
        'comments' => Type\optional(Type\vec(Type\shape([
            'user' => Type\string(),
            'comment' => Type\string()
        ]))),
    ])),
    'dictionary' => Type\dict(Type\string(), Type\vec(Type\shape([
        'title' => Type\string(),
        'content' => Type\string(),
    ]))),
    'pagination' => Type\Shape([
        'currentPage' => Type\uint(),
        'totalPages' => Type\uint(),
        'perPage' => Type\uint(),
        'totalRows' => Type\uint(),
    ])
]);

try {
    $shape->coerce([
        'name' => 'ok',
        'articles' => [
            [
                'title' => 'ok',
                'content' => 'ok',
                'likes' => 1,
                'comments' => [
                    [
                        'user' => 'ok',
                        'comment' => 'ok'
                    ],
                    [
                        'user' => 'ok',
                        'comment' =>'ok',
                    ]
                ]
            ]
        ],
       'dictionary' => [
           'key' => [
               [
                   'title' => 'ok',
                   'content' => 'ok',
               ]
           ]
       ]
    ]);
} catch (Type\Exception\CoercionException $e) {
    echo $e->getMessage().PHP_EOL;
}

Results in:

Could not coerce "array" to type "array{'name': string, 'articles': vec<array{'title': string, 'content': string, 'likes': int, 'comments'?: vec<array{'user': string, 'comment': string}>}>, 'dictionary': dict<string, vec<array{'title': string, 'content': string}>>, 'pagination': array{'currentPage': uint, 'totalPages': uint, 'perPage': uint, 'totalRows': uint}}": at path pagination

The changed I made do have quite an impact on performance, but tried to keep it at a minimum. Mainly vecs and dicts are suffering. Not sure what the accepted range is.

The impact on shapes are minimal:

(See #412)

[coveralls]

Pull Request Test Coverage Report for Build 6666122755

• 26 of 26 (100.0%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.004%) to 99.003%

---

Totals
Change from base Build 6487837444:	0.004%
Covered Lines:	4170
Relevant Lines:	4212

---

💛 - Coveralls

[veewee]

I'm +1 for this change!

To me, It is (at first feeling acceptibally) slower but at least it will give you helpful error messages.
Not sure how other people see this.

Some additional comments on the code:

• You only cover coerce(). We could have this on assert() as well?
• You currently don't cover paths for the types: map, mutable_map, vector, mutable_vector, non_empty_vec, non_empty_dict, mixed_dict, mixed_vec

[veewee]

string concatenations are fast, but maybe it helps to build the frame name outside of the loop and use it instead of always recalculating the frame name?
It will always be the same value.

[veewee]

Also here It might help to build the frame name outside of the loop.

[veewee]

It's a start, but we'll need tests for every changed type individually.

[veewee]

This might become a bit too slow on big data structures.
An alternative approach could be to re-run the assertions / coercions and collect that more advanced path information on failure only.

This issue needs some more thoughts. I'm gonna keep it open for now.