Fixing default import template doesn't extract columns from the latest uploaded file.

[justin-lau]

This MR fixes the issue described below.

Expected behavior

When the user decided he wants to replace the previously uploaded CSV file with another one, the updated columns should be extracted from the latest uploaded file.

Actual behavior

The columns are always extracted from the first uploaded file, regardless of subsequent changes to the file.

Reproduce steps

On the default CVS import template:

1. Upload a file.
2. Upload another totally different file. Should see that the columns are still from the first file.

October build

Master at 2659ae7

[justin-lau]

I have written a test case for this, but I couldn't get the database working, without failing some of the existing tests.

public function testGetImportFilePath() {
    $model = new ExampleImportModel;
    $sessionKey = uniqid('session_key', true);

    $file1 = File::create([
        'data' => base_path().'/tests/fixtures/backend/models/ImportModel/file_1.txt'
    ]);

    $file2 = File::create([
        'data' => base_path().'/tests/fixtures/backend/models/ImportModel/file_2.txt'
    ]);

    $model->import_file()->add($file1, $sessionKey);
    $model->import_file()->add($file2, $sessionKey);

    $this->assertEquals(
        $file2->getLocalPath(), $model->getImportFilePath($sessionKey),
        'ImportModel::getImportFilePath() should return the last uploaded file.'
    );
}

[daftspunk]

Thanks for taking the time to look in to this.