Feature: Allow Sushi to work even when there is no data available.

README.md

@@ -143,3 +143,28 @@ class Role extends Model
     }
 }
 ```
+### Handling Empty Datasets
+Sushi reads the first row in your dataset to work out the scheme of the SQLite table. If you are using `getRows()` and this returns an empty array (e.g an API returns nothing back) then Sushi would throw an error.
+
+If you would like Sushi to work even if the dataset is empty, you can define your schema in the optional `protected $schema` array. 
+
+> Note: If you choose to use your own ->getRows() method, the rows will NOT be cached between requests.
+
+```php
+class Currency extends Model
+{
+    use \Sushi\Sushi;
+
+    protected $schema = [
+        'id' => 'integer',
+        'name' => 'string',
+        'symbol' => 'string',
+        'precision' => 'float'
+    ];
+
+    public function getRows()
+    {
+        return [];
+    }
+}
+```

phpunit.xml.bak

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/8.5/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         executionOrder="depends,defects"
+         forceCoversAnnotation="true"
+         colors="true"
+         beStrictAboutCoversAnnotation="true"
+         beStrictAboutOutputDuringTests="true"
+         beStrictAboutTodoAnnotatedTests="true"
+         verbose="true">
+    <testsuites>
+        <testsuite name="default">
+            <directory suffix="Test.php">tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+</phpunit>

src/Sushi.php

@@ -83,9 +83,23 @@ protected static function setSqliteConnection($database)
     public function migrate()
     {
         $rows = $this->getRows();
-        $firstRow = $rows[0];
         $tableName = $this->getTable();
 
+        if (count($rows)) {
+            $this->createTable($tableName, $rows[0]);
+        } else {
+            $this->createTableWithNoData($tableName);
+        }
+
+        foreach (array_chunk($rows, 100) ?? [] as $inserts) {
+            if (!empty($inserts)) {
+                static::insert($inserts);
+            }
+        }
+    }
+
+    public function createTable(string $tableName, $firstRow)
+    {
         static::resolveConnection()->getSchemaBuilder()->create($tableName, function ($table) use ($firstRow) {
             // Add the "id" column if it doesn't already exist in the rows.
             if ($this->incrementing && ! array_key_exists($this->primaryKey, $firstRow)) {
@@ -126,12 +140,30 @@ public function migrate()
                 $table->timestamps();
             }
         });
+    }
 
-        foreach (array_chunk($rows, 100) ?? [] as $inserts) {
-            if (!empty($inserts)) {
-                static::insert($inserts);
+    public function createTableWithNoData(string $tableName)
+    {
+        static::resolveConnection()->getSchemaBuilder()->create($tableName, function ($table) {
+            $schema = $this->schema;
+
+            if ($this->incrementing && ! in_array($this->primaryKey, array_keys($schema))) {
+                $table->increments($this->primaryKey);
             }
-        }
+
+            foreach ($schema as $name => $type) {
+                if ($name === $this->primaryKey && $type == 'integer') {
+                    $table->increments($this->primaryKey);
+                    continue;
+                }
+
+                $table->{$type}($name)->nullable();
+            }
+
+            if ($this->usesTimestamps() && (! in_array('updated_at', array_keys($schema)) || ! in_array('created_at', array_keys($schema)))) {
+                $table->timestamps();
+            }
+        });
     }
 
     public function usesTimestamps()

tests/SushiTest.php

@@ -14,7 +14,7 @@ public function setUp(): void
     {
         parent::setUp();
 
-        config(['sushi.cache-path' => $this->cachePath = __DIR__.'/cache']);
+        config(['sushi.cache-path' => $this->cachePath = __DIR__ . '/cache']);
 
         if (! file_exists($this->cachePath)) {
             mkdir($this->cachePath, 0777, true);
@@ -78,7 +78,7 @@ function models_using_the_get_rows_property_arent_cached()
     /** @test */
     function uses_in_memory_if_the_cache_directory_is_not_writeable_or_not_found()
     {
-        config(['sushi.cache-path' => $path = __DIR__.'/non-existant-path']);
+        config(['sushi.cache-path' => $path = __DIR__ . '/non-existant-path']);
 
         Foo::count();
 
@@ -116,6 +116,13 @@ function adds_primary_key_if_needed()
         $this->assertEquals([5,6], ModelWithNonStandardKeys::orderBy('id')->pluck('id')->toArray());
         $this->assertEquals(1, Foo::find(1)->getKey());
     }
+
+
+    /** @test */
+    function it_returns_an_empty_collection()
+    {
+        $this->assertEquals(0, Blank::count());
+    }
 }
 
 class Foo extends Model
@@ -154,7 +161,8 @@ class ModelWithVaryingTypeColumns extends Model
 {
     use \Sushi\Sushi;
 
-    public function getRows() {
+    public function getRows()
+    {
         return [[
             'int' => 123,
             'float' => 123.456,
@@ -219,3 +227,15 @@ class Baz extends Model
 {
     use \Sushi\Sushi;
 }
+
+class Blank extends Model
+{
+    use \Sushi\Sushi;
+
+    protected $columns = [
+        'id' => 'integer',
+        'name' => 'string'
+    ];
+
+    protected $rows = [];
+}