fix(testing): OS Agnostic directory handling

Use the stdlib to generate temp directories and build filenames rather
than hardcoded strings with forward-slash separators.

- Should allow the tests to run on non-unixy operating systems
- Should remove the possibility of conflicts with existing files
- Might allow us to parallelize tests? May look into it later.

I don't have a windows machine to test this on so I can't guarantee it
will work.

Author: rbuchberger

docs/devs/contributing/testing.md

@@ -19,5 +19,3 @@ The primary way to run these checks is `rake`:
 * Depending on your environment, you may need to prefix all rake commands with `bundle exec`
 * Simplecov is set up -- you'll get a measurement of coverage in the test output and a nice report
   in the `coverage` directory.
-* The tests use the `/tmp/` directory directly, which I'm pretty sure means it won't work on
-  Windows. This is fixable, so if that gets in your way just ask.

test/integration/integration_test_helper.rb

@@ -28,7 +28,7 @@ def tested_base(params = 'rms.jpg')
   end
 
   def rms_filename(width: 100, format: 'jpg')
-    File.join temp_dir, rms_url(width: width, format: format)
+    temp_dir(rms_url(width: width, format: format))
   end
 
   def rms_url(width: 100, format: 'jpg')
@@ -60,7 +60,7 @@ def spx_url(width: 100, format: 'jpg')
   end
 
   def spx_filename(width: 100, format: 'jpg', crop: '')
-    File.join temp_dir, spx_url(width: width, format: format, crop: crop)
+    temp_dir(spx_url(width: width, format: format, crop: crop))
   end
 
   def std_spx_ss

test/integration/test_params.rb

@@ -63,7 +63,7 @@ def test_crop
     assert_equal correct, output.at_css('img')['srcset']
 
     generated_dimensions =
-      Vips::Image.new_from_file(temp_dir('generated/rms-100-7ce20d78f.jpg'))
+      Vips::Image.new_from_file(temp_dir('generated', 'rms-100-7ce20d78f.jpg'))
                  .size
 
     assert_in_delta aspect_float(10, 1),
@@ -117,7 +117,7 @@ def test_escaped_whitespace
 
     assert_equal src, img['src']
     assert_equal ss, img['srcset']
-    assert_path_exists(temp_dir('generated/rms with space-100-9f9ef26e5.jpg'))
+    assert_path_exists(temp_dir('generated', 'rms with space-100-9f9ef26e5.jpg'))
   end
 
   def test_quoted_whitespace
@@ -132,7 +132,7 @@ def test_quoted_whitespace
 
     assert_equal src, img['src']
     assert_equal ss, img['srcset']
-    assert_path_exists(temp_dir('generated/rms with space-100-9f9ef26e5.jpg'))
+    assert_path_exists(temp_dir('generated', 'rms with space-100-9f9ef26e5.jpg'))
   end
 
   def test_empty_params

test/integration/test_presets.rb

@@ -15,7 +15,7 @@ def teardown
   # formats webp, original
   def test_picture_files
     tested('auto rms.jpg')
-    files = Dir.glob(temp_dir('generated' + '/*'))
+    files = Dir.glob(temp_dir('generated', '*'))
 
     assert_equal(6, files.length)
     assert_includes stdout, 'Generating'
@@ -218,7 +218,7 @@ def test_fallback_exists
     File.unstub :exist?
     tested 'fallback rms.jpg'
 
-    files = Dir.glob(temp_dir('generated') + '/rms-35-?????????.webp')
+    files = Dir.glob(temp_dir('generated', 'rms-35-?????????.webp'))
 
     assert_equal 1, files.length
   end
@@ -271,10 +271,10 @@ def test_crop
     tested 'crop rms.jpg mobile: spx.jpg'
 
     rms_dimensions =
-      Image.new_from_file(temp_dir('generated/rms-100-ced21b33d.jpg')).size
+      Image.new_from_file(temp_dir('generated', 'rms-100-ced21b33d.jpg')).size
 
     spx_dimensions =
-      Image.new_from_file(temp_dir('generated/spx-100-63d4bc0d5.jpg')).size
+      Image.new_from_file(temp_dir('generated', 'spx-100-63d4bc0d5.jpg')).size
 
     assert_in_delta aspect_float(3, 2), aspect_float(*rms_dimensions), 0.03
     assert_in_delta aspect_float(16, 9), aspect_float(*spx_dimensions), 0.03

test/test_helper.rb

@@ -40,7 +40,9 @@ def aspect_float(width, height)
   end
 
   def temp_dir(*descendents)
-    File.join '/tmp/jpt', *descendents
+    @temp_dir ||= Dir.mktmpdir
+
+    File.join(@temp_dir, *descendents)
   end
 
   # We're having trouble with tests failing because whatever system is running

test/unit/images/test_image_file.rb

@@ -38,7 +38,7 @@ def format
   end
 
   def filename
-    File.join(temp_dir, dest_name)
+    temp_dir(dest_name)
   end
 
   def gen_config
@@ -186,8 +186,6 @@ def test_no_strip_metadata
   end
 
   def test_dest_dir
-    refute_path_exists temp_dir
-
     tested
 
     assert_path_exists temp_dir

test/unit/test_cache.rb

@@ -6,7 +6,7 @@ class TestCache < Minitest::Test
 
   def setup
     PictureTag.stubs(site: Object.new)
-    PictureTag.site.stubs(cache_dir: '/tmp/', config: {})
+    PictureTag.site.stubs(cache_dir: temp_dir, config: {})
   end
 
   def tested(name = 'img.jpg')
@@ -37,7 +37,7 @@ def test_write_data
     tested[:digest] = 'scruffer pupper'
     tested.write
 
-    assert_path_exists temp_dir('img.jpg.json')
+    assert_path_exists temp_dir('jpt', 'img.jpg.json')
   end
 
   def test_retrieve_data
@@ -49,11 +49,11 @@ def test_retrieve_data
 
   # Handles filenames with directories in them
   def test_subdirectory_name
-    tested('somedir/img.jpg')
+    tested(File.join('somedir', 'img.jpg'))
     tested[:digest] = 'abc123'
     tested.write
 
-    assert_path_exists temp_dir('somedir/img.jpg.json')
+    assert_path_exists temp_dir('jpt', 'somedir', 'img.jpg.json')
   end
 
   # Jekyll has a flag to disable caching; we must respect it.