#306

backend/spec/services/material_file_sha256_spec.rb

@@ -0,0 +1,23 @@
+require 'rails_helper'
+
+RSpec.describe MaterialFileSha256 do
+  describe '.metadata_sha256' do
+    it 'reads sha256 from Hash metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: { 'sha256' => 'abc123' })
+
+      expect(described_class.metadata_sha256(blob)).to eq('abc123')
+    end
+
+    it 'reads sha256 from JSON string metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: '{"sha256":"abc123"}')
+
+      expect(described_class.metadata_sha256(blob)).to eq('abc123')
+    end
+
+    it 'returns nil for invalid metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: '{')
+
+      expect(described_class.metadata_sha256(blob)).to be_nil
+    end
+  end
+end