🧪 test(composer): add unit tests for GenerateBarcode

[adcondev]

🎯 What: Added comprehensive unit tests for GenerateBarcode in pkg/composer/escpos_composer.go.
📊 Coverage: Covered happy paths (CODE128, EAN13) and error cases (invalid width, height, HRI position, HRI font, empty data).
✨ Result: Improved test coverage and ensured reliability of barcode command generation logic.

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PR created automatically by Jules for task 4668165121956780641 started by @adcondev

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[github-actions]

👋 Thanks for opening this PR, @adcondev!

Here's what will happen next:

• 🤖 Automated checks will run
• 🏷️ Labels will be added automatically
• 👀 A maintainer will review your changes

Please make sure:

• ✅ All tests pass
• 📝 The PR title follows conventional commits
• 📋 The PR template is filled out completely

[github-actions]

⚡ Benchmark Results

📈 Performance Comparison

📊 Click to expand detailed results

Current Branch Results

BenchmarkNewDocument-4    	1000000000	         0.3114 ns/op	       0 B/op	       0 allocs/op
BenchmarkBuildSimple-4    	 3670780	       329.4 ns/op	     240 B/op	       4 allocs/op
BenchmarkBuildComplex-4   	  414739	      2760 ns/op	    1809 B/op	      25 allocs/op
BenchmarkToJSON-4         	  520362	      2082 ns/op	     592 B/op	       3 allocs/op
BenchmarkParseDocument_Minimal-4    	  505144	      2329 ns/op	     568 B/op	      14 allocs/op
BenchmarkParseDocument_Receipt-4    	   88273	     12840 ns/op	    2392 B/op	      34 allocs/op
BenchmarkCommandUnmarshal_Text-4    	  406977	      2715 ns/op	     568 B/op	      19 allocs/op
BenchmarkCommandUnmarshal_Table-4   	  272108	      4201 ns/op	     944 B/op	      21 allocs/op
BenchmarkTextCommandParsing-4       	  515166	      2131 ns/op	     544 B/op	      16 allocs/op
BenchmarkTableCommandParsing-4      	  237627	      4868 ns/op	    1000 B/op	      29 allocs/op
BenchmarkParseHexString-4           	 8615732	       139.7 ns/op	      48 B/op	       2 allocs/op
BenchmarkCleanHexString-4           	 6603477	       180.5 ns/op	      64 B/op	       2 allocs/op
BenchmarkContainsSequence-4         	370735526	         3.256 ns/op	       0 B/op	       0 allocs/op
BenchmarkCheckCriticalCommands-4    	31506909	        37.14 ns/op	       0 B/op	       0 allocs/op
BenchmarkDocument_Validate-4       	14493747	        82.80 ns/op	       0 B/op	       0 allocs/op
BenchmarkParseDocument_Simple-4    	  487539	      2399 ns/op	     568 B/op	      14 allocs/op
BenchmarkParseDocument_Complex-4   	  137965	      8518 ns/op	    1352 B/op	      26 allocs/op
BenchmarkPrintImage_Small-4             	     583	   1955898 ns/op	 3469937 B/op	      24 allocs/op
BenchmarkPrintImage_Medium-4            	     312	   3593006 ns/op	 5481087 B/op	      24 allocs/op
BenchmarkPrintImage_ThermalPreview-4    	     135	   8579756 ns/op	 5235270 B/op	  230723 allocs/op

Base Branch Results

BenchmarkNewDocument-4    	1000000000	         0.3132 ns/op	       0 B/op	       0 allocs/op
BenchmarkBuildSimple-4    	 3607533	       333.1 ns/op	     240 B/op	       4 allocs/op
BenchmarkBuildComplex-4   	  386850	      3080 ns/op	    1809 B/op	      25 allocs/op
BenchmarkToJSON-4         	  503912	      2171 ns/op	     592 B/op	       3 allocs/op
BenchmarkParseDocument_Minimal-4    	  500893	      2344 ns/op	     568 B/op	      14 allocs/op
BenchmarkParseDocument_Receipt-4    	   89463	     13611 ns/op	    2392 B/op	      34 allocs/op
BenchmarkCommandUnmarshal_Text-4    	  419140	      2737 ns/op	     568 B/op	      19 allocs/op
BenchmarkCommandUnmarshal_Table-4   	  268255	      4358 ns/op	     944 B/op	      21 allocs/op
BenchmarkTextCommandParsing-4       	  493143	      2212 ns/op	     544 B/op	      16 allocs/op
BenchmarkTableCommandParsing-4      	  232785	      5110 ns/op	    1000 B/op	      29 allocs/op
BenchmarkParseHexString-4           	 7413310	       162.3 ns/op	      48 B/op	       2 allocs/op
BenchmarkCleanHexString-4           	 6275983	       187.5 ns/op	      64 B/op	       2 allocs/op
BenchmarkContainsSequence-4         	296064094	         4.070 ns/op	       0 B/op	       0 allocs/op
BenchmarkCheckCriticalCommands-4    	32766406	        36.85 ns/op	       0 B/op	       0 allocs/op
BenchmarkDocument_Validate-4       	14395582	        83.39 ns/op	       0 B/op	       0 allocs/op
BenchmarkParseDocument_Simple-4    	  475616	      2455 ns/op	     568 B/op	      14 allocs/op
BenchmarkParseDocument_Complex-4   	  135075	      8854 ns/op	    1352 B/op	      26 allocs/op
BenchmarkPrintImage_Small-4             	     560	   2034931 ns/op	 3469944 B/op	      24 allocs/op
BenchmarkPrintImage_Medium-4            	     318	   4027319 ns/op	 5481083 B/op	      24 allocs/op
BenchmarkPrintImage_ThermalPreview-4    	     138	   8714028 ns/op	 5231175 B/op	  230423 allocs/op

💡 Note: Use benchstat for statistical comparison

🎯 Summary

• Total Benchmarks: 32
• Average Speed: 2652385 ns/op
• Average Memory: 2396936 B/op
• Average Allocations: 41093 allocs/op