Throws a validation exception now if attempting to cast an object to string (#42)

* Throws a validation exception now if attempting to cast an object to string.

* Removed extraneous use statement.

* Added void return types for PHPUnit 8.5 compatibility. Added Throwable to StringField class.

* Fixed array_key_exists() usage in Schema.php

* Formatting update as per travis PHP7.1 cs check

Author: Ronald Diaz

.travis.yml

@@ -3,6 +3,7 @@ php:
   - '7.1'
   - '7.2'
   - '7.3'
+  - '7.4'
 before_script:
   - COMPOSER_DISABLE_XDEBUG_WARN=1 composer install --prefer-dist
 script:

composer.json

@@ -3,7 +3,7 @@
     "description": "A utility library for working with Table Schema",
     "license": "MIT",
     "require": {
-        "php": ">=7.1.0 <7.4.0",
+        "php": ">=7.1.0",
         "justinrainbow/json-schema": "^5.2",
         "nesbot/carbon": "^1.22",
         "jmikola/geojson": "^1.0"

src/Fields/StringField.php

@@ -2,6 +2,8 @@
 
 namespace frictionlessdata\tableschema\Fields;
 
+use frictionlessdata\tableschema\Exceptions\FieldValidationException;
+
 class StringField extends BaseField
 {
     public function inferProperties($val, $lenient = false)
@@ -19,13 +21,13 @@ public function inferProperties($val, $lenient = false)
      *
      * @return string
      *
-     * @throws \frictionlessdata\tableschema\Exceptions\FieldValidationException;
+     * @throws FieldValidationException;
      */
     protected function validateCastValue($val)
     {
         try {
             $val = (string) $val;
-        } catch (\Exception $e) {
+        } catch (\Throwable $e) {
             $val = json_encode($val);
         }
         switch ($this->format()) {

src/Schema.php

@@ -143,7 +143,9 @@ public function fields($newFields = null)
         if (is_null($newFields)) {
             if (empty($this->fieldsCache)) {
                 foreach ($this->descriptor()->fields as $fieldDescriptor) {
-                    if (!array_key_exists('type', $fieldDescriptor)) {
+                    if ((is_object($fieldDescriptor) && !isset($fieldDescriptor->type))
+                        || (is_array($fieldDescriptor) && !array_key_exists('type', $fieldDescriptor))
+                    ) {
                         $field = new $this->DEFAULT_FIELD_CLASS($fieldDescriptor);
                     } else {
                         $field = Fields\FieldsFactory::field($fieldDescriptor);

tests/FieldTest.php

@@ -17,7 +17,7 @@ class FieldTest extends TestCase
     public $DESCRIPTOR_MIN;
     public $DESCRIPTOR_MAX;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->DESCRIPTOR_WITHOUT_TYPE = [
             'name' => 'id',

tests/SchemaTest.php

@@ -19,7 +19,7 @@ class SchemaTest extends TestCase
     public $schemaValidSimpleFilename;
     public $schemaInvalidMultipleErrorsFilename;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->simpleDescriptorJson = '{
             "fields": [
@@ -546,7 +546,7 @@ public function testSchemaInferCsvDialect()
         ], $schema->descriptor());
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         foreach ($this->tempFiles as $tempFile) {
             if (file_exists($tempFile)) {

tests/TableTest.php

@@ -14,7 +14,7 @@
 
 class TableTest extends TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->fixturesPath = dirname(__FILE__).DIRECTORY_SEPARATOR.'fixtures';
         $this->validSchema = new Schema((object) [