Improve casting from BSON to decimal

Author: stubbo

src/Eloquent/Model.php

@@ -12,13 +12,16 @@
 use Illuminate\Database\Eloquent\Model as BaseModel;
 use Illuminate\Database\Eloquent\Relations\Relation;
 use Illuminate\Support\Arr;
+use Illuminate\Support\Exceptions\MathException;
 use Illuminate\Support\Facades\Date;
 use Illuminate\Support\Str;
 use MongoDB\BSON\Binary;
 use MongoDB\BSON\Decimal128;
 use MongoDB\BSON\ObjectID;
+use MongoDB\BSON\Type;
 use MongoDB\BSON\UTCDateTime;
 use MongoDB\Laravel\Query\Builder as QueryBuilder;
+use Stringable;
 
 use function array_key_exists;
 use function array_keys;
@@ -275,12 +278,22 @@ public function setAttribute($key, $value)
         return parent::setAttribute($key, $value);
     }
 
-    /** @inheritdoc */
+    /**
+     * @param mixed $value
+     *
+     * @inheritdoc
+     */
     protected function asDecimal($value, $decimals)
     {
-        if ($value instanceof Decimal128) {
-            // Convert it to a string to round, want to make it act exactly like we expect.
-            $value = (string) $value;
+        // Convert BSON to string.
+        if ($this->isBSON($value)) {
+            if ($value instanceof Binary) {
+                $value = $value->getData();
+            } elseif ($value instanceof Stringable) {
+                $value = (string) $value;
+            } else {
+                throw new MathException('BSON type ' . $value::class . ' cannot be converted to string');
+            }
         }
 
         return parent::asDecimal($value, $decimals);
@@ -703,4 +716,16 @@ protected function addCastAttributesToArray(array $attributes, array $mutatedAtt
 
         return $attributes;
     }
+
+    /**
+     * Is a value a BSON type?
+     *
+     * @param mixed $value
+     *
+     * @return bool
+     */
+    protected function isBSON(mixed $value): bool
+    {
+        return $value instanceof Type;
+    }
 }

tests/Casts/DecimalTest.php

@@ -4,10 +4,18 @@
 
 namespace MongoDB\Laravel\Tests\Casts;
 
+use Illuminate\Support\Exceptions\MathException;
+use MongoDB\BSON\Binary;
 use MongoDB\BSON\Decimal128;
+use MongoDB\BSON\Int64;
+use MongoDB\BSON\Javascript;
+use MongoDB\BSON\UTCDateTime;
+use MongoDB\Laravel\Collection;
 use MongoDB\Laravel\Tests\Models\Casting;
 use MongoDB\Laravel\Tests\TestCase;
 
+use function now;
+
 class DecimalTest extends TestCase
 {
     protected function setUp(): void
@@ -73,4 +81,51 @@ public function testDecimalAsDecimal128(): void
         self::assertInstanceOf(Decimal128::class, $model->getRawOriginal('decimalNumber'));
         self::assertEquals('9999.90', $model->decimalNumber);
     }
+
+    public function testOtherBSONTypes(): void
+    {
+        $modelId = $this->setBSONType(new Int64(100));
+        $model = Casting::query()->find($modelId);
+
+        self::assertIsString($model->decimalNumber);
+        self::assertIsInt($model->getRawOriginal('decimalNumber'));
+        self::assertEquals('100.00', $model->decimalNumber);
+
+        // Update decimalNumber to a Binary type
+        $this->setBSONType(new Binary('100.1234', Binary::TYPE_GENERIC), $modelId);
+        $model->refresh();
+
+        self::assertIsString($model->decimalNumber);
+        self::assertInstanceOf(Binary::class, $model->getRawOriginal('decimalNumber'));
+        self::assertEquals('100.12', $model->decimalNumber);
+
+        $this->setBSONType(new Javascript('function() { return 100; }'), $modelId);
+        $model->refresh();
+        self::expectException(MathException::class);
+        self::expectExceptionMessage('Unable to cast value to a decimal.');
+        $model->decimalNumber;
+        self::assertInstanceOf(Javascript::class, $model->getRawOriginal('decimalNumber'));
+
+        $this->setBSONType(new UTCDateTime(now()), $modelId);
+        $model->refresh();
+        self::expectException(MathException::class);
+        self::expectExceptionMessage('Unable to cast value to a decimal.');
+        $model->decimalNumber;
+        self::assertInstanceOf(UTCDateTime::class, $model->getRawOriginal('decimalNumber'));
+    }
+
+    private function setBSONType($value, $id = null)
+    {
+        // Do a raw insert/update, so we can enforce the type we want
+        return Casting::raw(function (Collection $collection) use ($id, $value) {
+            if (! empty($id)) {
+                return $collection->updateOne(
+                    ['_id' => $id],
+                    ['$set' => ['decimalNumber' => $value]],
+                );
+            }
+
+            return $collection->insertOne(['decimalNumber' => $value])->getInsertedId();
+        });
+    }
 }