golib/encoding/hexa/TESTING.md

Hexadecimal Encoding Package - Testing Documentation

Comprehensive testing guide for the hexadecimal encoding package using Ginkgo v2/Gomega BDD framework.

AI Disclaimer (EU AI Act Article 50.4): AI assistance was used solely for test generation, documentation, and bug resolution under human supervision.

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Table of Contents

• Overview
• Test Framework
• Test Organization
• Running Tests
• Test Coverage
• Test Scenarios
• Best Practices
• CI/CD Integration
• Contributing

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Overview

The hexa package features comprehensive testing covering encoding, decoding, streaming operations, and edge cases.

Test Metrics

Metric	Value	Status
Total Specs	97	✅ All passing
Code Coverage	89.7%	✅ Excellent
Framework	Ginkgo v2 + Gomega	✅ BDD
Edge Cases	25+	✅ Robust

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Test Framework

Ginkgo v2 + Gomega

Features:

• BDD-style test organization
• Table-driven tests for encoding/decoding
• Comprehensive edge case coverage
• Round-trip verification
• Streaming I/O testing

Installation:

go get github.com/onsi/ginkgo/v2/ginkgo
go get github.com/onsi/gomega

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Test Organization

Test Files

encoding/hexa/
├── hexa_suite_test.go    # Suite setup
├── hexa_test.go          # Basic hexa tests (15+ specs)
├── encode_test.go        # Encoding tests (20+ specs)
├── reader_test.go        # Streaming read tests (15+ specs)
├── writer_test.go        # Streaming write tests (20+ specs)
└── edge_test.go          # Edge cases & errors (25+ specs)

Test Categories

1. Basic Operations - Creation, basic encode/decode
2. Encoding - Various input sizes and patterns
3. Decoding - Valid/invalid hex, case sensitivity
4. Streaming - Reader/Writer interfaces
5. Edge Cases - Empty, invalid, large data
6. Round-Trip - Encode → Decode verification

---

Running Tests

Quick Test

cd encoding/hexa
go test -v

With Coverage

go test -v -cover
go test -coverprofile=coverage.out
go tool cover -html=coverage.out

Using Ginkgo

# Run all tests
ginkgo -v

# With coverage
ginkgo -v -cover

# Parallel execution
ginkgo -v -p

# Focus on specific tests
ginkgo -v -focus="Encoding"

# Skip tests
ginkgo -v -skip="Edge cases"

Verbose Output

go test -v -count=1

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Test Coverage

Coverage by Component

Component	File	Specs	Coverage	Notes
Interface	interface.go	5+	95%	New function
Encoding	model.go	20+	92%	Encode operations
Decoding	model.go	20+	92%	Decode operations
Streaming	model.go	30+	85%	Reader/Writer
Edge Cases	all	25+	88%	Error handling

Overall Coverage: 89.7%

Coverage Gaps

Minor gaps in:

• Some I/O error conditions
• Extreme memory scenarios
• Rare buffer edge cases

---

Test Scenarios

1. Basic Operations

Scenarios:

• Create coder instance
• Reset (no-op)
• Instance reuse

Example:

var _ = Describe("Basic Operations", func() {
    It("should create new coder", func() {
        coder := New()
        Expect(coder).NotTo(BeNil())
    })
    
    It("should be stateless", func() {
        coder1 := New()
        coder2 := New()
        
        data := []byte("test")
        enc1 := coder1.Encode(data)
        enc2 := coder2.Encode(data)
        
        Expect(enc1).To(Equal(enc2))
    })
    
    It("should handle reset (no-op)", func() {
        coder := New()
        data := []byte("test")
        
        enc1 := coder.Encode(data)
        coder.Reset()  // No-op
        enc2 := coder.Encode(data)
        
        Expect(enc1).To(Equal(enc2))
    })
})

2. Encoding Tests

Scenarios:

• Encode various data sizes
• Encode empty data
• Encode large data
• Verify output format (lowercase)
• Verify size (2× input)

Example:

var _ = Describe("Encoding", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    It("should encode to lowercase hex", func() {
        input := []byte("Hello")
        encoded := coder.Encode(input)
        
        Expect(string(encoded)).To(Equal("48656c6c6f"))
        // Verify lowercase (not "48656C6C6F")
    })
    
    It("should double the size", func() {
        input := []byte("Test")
        encoded := coder.Encode(input)
        
        Expect(len(encoded)).To(Equal(len(input) * 2))
    })
    
    It("should encode empty data", func() {
        input := []byte{}
        encoded := coder.Encode(input)
        
        Expect(len(encoded)).To(Equal(0))
    })
    
    It("should encode binary data", func() {
        input := []byte{0x00, 0xFF, 0xAA, 0x55}
        encoded := coder.Encode(input)
        
        Expect(string(encoded)).To(Equal("00ffaa55"))
    })
})

3. Decoding Tests

Scenarios:

• Decode valid hex
• Case-insensitive decoding
• Detect invalid characters
• Detect odd length
• Round-trip verification

Example:

var _ = Describe("Decoding", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    It("should decode valid hex", func() {
        hexData := []byte("48656c6c6f")
        decoded, err := coder.Decode(hexData)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(string(decoded)).To(Equal("Hello"))
    })
    
    It("should be case-insensitive", func() {
        lower := []byte("48656c6c6f")
        upper := []byte("48656C6C6F")
        mixed := []byte("48656C6c6F")
        
        dec1, _ := coder.Decode(lower)
        dec2, _ := coder.Decode(upper)
        dec3, _ := coder.Decode(mixed)
        
        Expect(dec1).To(Equal(dec2))
        Expect(dec2).To(Equal(dec3))
    })
    
    It("should reject invalid hex characters", func() {
        invalidHex := []byte("48656g6c6f")  // 'g' is invalid
        _, err := coder.Decode(invalidHex)
        
        Expect(err).To(HaveOccurred())
    })
    
    It("should reject odd length", func() {
        oddHex := []byte("48656c6c6")  // Odd length
        _, err := coder.Decode(oddHex)
        
        Expect(err).To(HaveOccurred())
    })
    
    It("should perform round-trip", func() {
        original := []byte("Round trip test")
        
        encoded := coder.Encode(original)
        decoded, err := coder.Decode(encoded)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(decoded).To(Equal(original))
    })
})

4. Streaming Tests

Scenarios:

• Encode via Reader
• Decode via Reader
• Handle large streams
• Handle empty streams
• Error propagation

Example:

var _ = Describe("Streaming Operations", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    It("should encode via reader", func() {
        input := []byte("Stream test")
        reader := bytes.NewReader(input)
        
        hexReader := coder.EncodeReader(reader)
        encoded, err := io.ReadAll(hexReader)
        
        Expect(err).NotTo(HaveOccurred())
        
        // Verify it's hex
        decoded, _ := coder.Decode(encoded)
        Expect(decoded).To(Equal(input))
    })
    
    It("should decode via reader", func() {
        hexData := []byte("53747265616d")
        reader := bytes.NewReader(hexData)
        
        binaryReader := coder.DecodeReader(reader)
        decoded, err := io.ReadAll(binaryReader)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(string(decoded)).To(Equal("Stream"))
    })
    
    It("should handle large streams", func() {
        // 1 MB of data
        largeData := make([]byte, 1024*1024)
        for i := range largeData {
            largeData[i] = byte(i % 256)
        }
        
        reader := bytes.NewReader(largeData)
        hexReader := coder.EncodeReader(reader)
        encoded, err := io.ReadAll(hexReader)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(len(encoded)).To(Equal(len(largeData) * 2))
    })
    
    It("should handle empty stream", func() {
        reader := bytes.NewReader([]byte{})
        hexReader := coder.EncodeReader(reader)
        encoded, err := io.ReadAll(hexReader)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(len(encoded)).To(Equal(0))
    })
})

5. Edge Case Tests

Scenarios:

• Nil input
• Zero-length input
• Very large input
• All zero bytes
• All 0xFF bytes
• Invalid UTF-8
• Special characters

Example:

var _ = Describe("Edge Cases", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    It("should handle nil input", func() {
        encoded := coder.Encode(nil)
        Expect(len(encoded)).To(Equal(0))
    })
    
    It("should handle zero bytes", func() {
        input := []byte{0x00, 0x00, 0x00}
        encoded := coder.Encode(input)
        
        Expect(string(encoded)).To(Equal("000000"))
    })
    
    It("should handle 0xFF bytes", func() {
        input := []byte{0xFF, 0xFF, 0xFF}
        encoded := coder.Encode(input)
        
        Expect(string(encoded)).To(Equal("ffffff"))
    })
    
    It("should handle large input", func() {
        // 10 MB
        largeData := make([]byte, 10*1024*1024)
        encoded := coder.Encode(largeData)
        
        Expect(len(encoded)).To(Equal(len(largeData) * 2))
    })
    
    It("should handle non-ASCII bytes", func() {
        input := []byte{0x80, 0x90, 0xA0, 0xF0}
        encoded := coder.Encode(input)
        decoded, err := coder.Decode(encoded)
        
        Expect(err).NotTo(HaveOccurred())
        Expect(decoded).To(Equal(input))
    })
    
    It("should detect whitespace in hex", func() {
        hexWithSpace := []byte("48 65 6c 6c 6f")
        _, err := coder.Decode(hexWithSpace)
        
        Expect(err).To(HaveOccurred())
    })
})

6. Table-Driven Tests

Example:

var _ = Describe("Encoding Table Tests", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    DescribeTable("encoding various inputs",
        func(input []byte, expected string) {
            encoded := coder.Encode(input)
            Expect(string(encoded)).To(Equal(expected))
        },
        Entry("empty", []byte{}, ""),
        Entry("single byte", []byte{0x48}, "48"),
        Entry("Hello", []byte("Hello"), "48656c6c6f"),
        Entry("binary", []byte{0x00, 0xFF}, "00ff"),
        Entry("spaces", []byte("a b"), "612062"),
    )
    
    DescribeTable("decoding various inputs",
        func(hex string, expected []byte) {
            decoded, err := coder.Decode([]byte(hex))
            Expect(err).NotTo(HaveOccurred())
            Expect(decoded).To(Equal(expected))
        },
        Entry("empty", "", []byte{}),
        Entry("single byte", "48", []byte{0x48}),
        Entry("lowercase", "48656c6c6f", []byte("Hello")),
        Entry("uppercase", "48656C6C6F", []byte("Hello")),
        Entry("mixed case", "48656C6c6F", []byte("Hello")),
    )
})

---

Best Practices

1. Use BeforeEach for Setup

var _ = Describe("Test Suite", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    It("test case", func() {
        // Use coder
    })
})

2. Test Round-Trips

It("should preserve data through round-trip", func() {
    original := []byte("Test data")
    
    encoded := coder.Encode(original)
    decoded, err := coder.Decode(encoded)
    
    Expect(err).NotTo(HaveOccurred())
    Expect(decoded).To(Equal(original))
})

3. Test Error Conditions

It("should handle errors gracefully", func() {
    invalidHex := []byte("zzzz")
    _, err := coder.Decode(invalidHex)
    
    Expect(err).To(HaveOccurred())
    Expect(err.Error()).To(ContainSubstring("invalid"))
})

4. Test Size Relationships

It("should verify size doubling", func() {
    input := []byte("test")
    encoded := coder.Encode(input)
    
    Expect(len(encoded)).To(Equal(len(input) * 2))
})

It("should verify size halving", func() {
    hexData := []byte("74657374")
    decoded, _ := coder.Decode(hexData)
    
    Expect(len(decoded)).To(Equal(len(hexData) / 2))
})

5. Test Case Insensitivity

It("should accept both cases", func() {
    lower, _ := coder.Decode([]byte("48656c6c6f"))
    upper, _ := coder.Decode([]byte("48656C6C6F"))
    
    Expect(lower).To(Equal(upper))
})

---

CI/CD Integration

GitHub Actions

test-hexa:
  runs-on: ubuntu-latest
  
  steps:
    - uses: actions/checkout@v3
    - uses: actions/setup-go@v4
      with:
        go-version: '1.21'
    
    - name: Test Hexa Package
      run: |
        cd encoding/hexa
        go test -v -race -cover
    
    - name: Upload Coverage
      uses: codecov/codecov-action@v3
      with:
        files: ./coverage.out

GitLab CI

test-hexa:
  script:
    - cd encoding/hexa
    - go test -v -race -cover
  
  coverage: '/coverage: \d+\.\d+% of statements/'

Coverage Reports

# Generate HTML coverage report
go test -coverprofile=coverage.out
go tool cover -html=coverage.out -o coverage.html

# View in browser
open coverage.html

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Contributing

When adding new features:

1. Write tests first (TDD approach)
2. Cover edge cases (empty, invalid, large, special chars)
3. Test round-trips (encode → decode = original)
4. Test case insensitivity (uppercase, lowercase, mixed)
5. Test streaming (Reader/Writer interfaces)
6. Update coverage metrics
7. Document test scenarios

Test Template

var _ = Describe("New Feature", func() {
    var coder Coder
    
    BeforeEach(func() {
        coder = New()
    })
    
    Describe("basic functionality", func() {
        It("should handle normal case", func() {
            result := operation(input)
            Expect(result).To(Equal(expected))
        })
    })
    
    Context("error conditions", func() {
        It("should handle invalid input", func() {
            _, err := operation(invalidInput)
            Expect(err).To(HaveOccurred())
        })
    })
    
    Context("edge cases", func() {
        It("should handle empty input", func() {
            result := operation([]byte{})
            Expect(len(result)).To(Equal(0))
        })
        
        It("should handle large input", func() {
            large := make([]byte, 1024*1024)
            result := operation(large)
            Expect(len(result)).To(BeNumerically(">", 0))
        })
    })
})

---

Support

For issues or questions:

• Test Failures: Check output with -v flag
• Coverage Gaps: Run go test -cover to identify
• Usage Examples: Review test files for patterns
• Feature Questions: See README.md
• Bug Reports: GitHub Issues

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AI Transparency Notice

In accordance with Article 50.4 of the EU AI Act, AI assistance has been used for testing, documentation, and bug fixing under human supervision.

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Part of the golib testing suite.