test: add unit tests for build_transformation_string method in BuildTransformationStringTest

Author: manu4543

test/imagekit/custom-tests/url-generation/build_transformation_string_test.rb

@@ -0,0 +1,131 @@
+# frozen_string_literal: true
+
+require_relative "../../test_helper"
+
+class BuildTransformationStringTest < Minitest::Test
+  def setup
+    @client = Imagekit::Client.new(
+      private_key: "test-key",
+      password: "test_password"
+    )
+  end
+
+  def test_should_return_empty_string_for_empty_transformation_array
+    result = @client.helper.build_transformation_string(nil)
+    assert_equal("", result)
+
+    result = @client.helper.build_transformation_string([])
+    assert_equal("", result)
+  end
+
+  def test_should_generate_transformation_string_for_width_only
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        width: 300.0
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "w-300"
+    assert_equal(expected, result)
+  end
+
+  def test_should_generate_transformation_string_for_multiple_parameters
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        width: 300.0,
+        height: 200.0
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "w-300,h-200"
+    assert_equal(expected, result)
+  end
+
+  def test_should_generate_transformation_string_for_chained_transformations
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        width: 300.0
+      ),
+      Imagekit::Models::Transformation.new(
+        height: 200.0
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "w-300:h-200"
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_empty_transformation_object
+    transformation = [
+      Imagekit::Models::Transformation.new
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = ""
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_transformation_with_overlay
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        overlay_text: "Hello"
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "l-text,i-Hello,l-end"
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_raw_transformation_parameter
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        raw: "custom-transform-123"
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "custom-transform-123"
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_mixed_parameters_with_raw
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        width: 300.0,
+        raw: "custom-param-123"
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "w-300,custom-param-123"
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_quality_parameter
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        quality: 80.0
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "q-80"
+    assert_equal(expected, result)
+  end
+
+  def test_should_handle_aspect_ratio_parameter
+    transformation = [
+      Imagekit::Models::Transformation.new(
+        aspect_ratio: "4:3"
+      )
+    ]
+
+    result = @client.helper.build_transformation_string(transformation)
+    expected = "ar-4:3"
+    assert_equal(expected, result)
+  end
+end