[testify-expert] Improve Test Quality: ./pkg/sliceutil/sliceutil_test.go

[agentic-workflows-dev]

Overview

The test file ./pkg/sliceutil/sliceutil_test.go has been selected for quality improvement by the Testify Uber Super Expert. This test file demonstrates excellent table-driven test structure and comprehensive coverage, but it uses manual error checking (if result != expected) instead of testify assertions. Modernizing to use testify will provide clearer error messages, better test output, and align with the repository's testing standards documented in specs/testing.md.

Current State

• Test File: ./pkg/sliceutil/sliceutil_test.go
• Source File: ./pkg/sliceutil/sliceutil.go
• Test Functions: 15 test functions (including benchmarks)
• Lines of Code: 378 lines
• Source Functions: 3 exported functions (100% tested)

Test Quality Analysis

Strengths ✅

1. Excellent table-driven test structure - All main tests (TestContains, TestContainsAny, TestContainsIgnoreCase) use proper table-driven patterns with descriptive test case names
2. Comprehensive edge case coverage - Tests cover empty slices, nil values, empty strings, unicode, duplicates, and large data sets
3. Performance benchmarks - Includes benchmark tests for all three functions
4. Good test organization - Tests are well-organized with clear separation between table-driven tests and additional edge case tests

Areas for Improvement 🎯

1. Testify Assertions

Current Issues:

• All tests use manual if result != expected checks with t.Error() or t.Errorf()
• Manual error checking is verbose and provides less context than testify assertions
• No distinction between setup failures (should use require) and test validations (should use assert)

Recommended Changes:

// ❌ CURRENT (manual checks)
result := Contains(tt.slice, tt.item)
if result != tt.expected {
    t.Errorf("Contains(%v, %q) = %v; want %v", tt.slice, tt.item, result, tt.expected)
}

// ✅ IMPROVED (testify)
result := Contains(tt.slice, tt.item)
assert.Equal(t, tt.expected, result, "Contains should return correct value for slice %v and item %q", tt.slice, tt.item)

// Alternative (more explicit)
if tt.expected {
    assert.True(t, result, "Contains should find %q in slice %v", tt.item, tt.slice)
} else {
    assert.False(t, result, "Contains should not find %q in slice %v", tt.item, tt.slice)
}

Why this matters:

• Testify provides clearer, more actionable error messages when tests fail
• The repository standard (per specs/testing.md) requires testify assertions
• Better integration with testing tools and IDEs
• Clearer distinction between critical setup (require.*) and validations (assert.*)

2. Import Statement

Current Issue:

• Missing testify import: "github.com/stretchr/testify/assert"

Recommended Change:

import (
    "testing"
    
    "github.com/stretchr/testify/assert"
)

3. Edge Case Tests - Use Table-Driven Pattern

Current Issues:

• Edge case tests like TestContains_LargeSlice, TestContains_SingleElement, etc. use manual assertions
• These could benefit from testify's clearer error messages

Recommended Improvements:

Example 1: TestContains_LargeSlice

// ❌ CURRENT
if !Contains(largeSlice, "a") {
    t.Error("Expected to find 'a' at beginning of large slice")
}

// ✅ IMPROVED
assert.True(t, Contains(largeSlice, "a"), "should find 'a' at beginning of large slice")
// OR even better:
assert.Contains(t, largeSlice, "a", "should find 'a' at beginning of large slice")

Example 2: TestContains_SingleElement

// ❌ CURRENT
slice := []string{"single"}
if !Contains(slice, "single") {
    t.Error("Expected to find item in single-element slice")
}
if Contains(slice, "other") {
    t.Error("Expected not to find different item in single-element slice")
}

// ✅ IMPROVED
slice := []string{"single"}
assert.True(t, Contains(slice, "single"), "should find item in single-element slice")
assert.False(t, Contains(slice, "other"), "should not find different item in single-element slice")

Example 3: TestContainsAny_MultipleMatches

// ❌ CURRENT
if !ContainsAny(s, "quick", "lazy") {
    t.Error("Expected to find at least one matching substring")
}

// ✅ IMPROVED
assert.True(t, ContainsAny(s, "quick", "lazy"), "should find at least one matching substring")

Example 4: TestContainsIgnoreCase_PartialMatch

// ❌ CURRENT
if !ContainsIgnoreCase(s, "hub") {
    t.Error("Expected to find partial match 'hub' in 'GitHub'")
}

// ✅ IMPROVED
assert.True(t, ContainsIgnoreCase(s, "hub"), "should find partial match 'hub' in 'GitHub'")

4. Consider assert.Contains for Slice Checks

Current Pattern:

result := Contains(tt.slice, tt.item)
assert.Equal(t, tt.expected, result, ...)

Alternative (when expecting true):

// For positive cases
if tt.expected {
    assert.Contains(t, tt.slice, tt.item, "slice should contain item")
} else {
    assert.NotContains(t, tt.slice, tt.item, "slice should not contain item")
}

Note: This is optional - assert.Equal works fine, but assert.Contains may be more semantic.

5. Enhanced Assertion Messages

Current Issues:

• Some manual error messages are good but could be more helpful
• Testify messages should guide developers to the problem

Recommended Pattern:

// Good assertion messages explain WHAT is being tested and WHY it matters
assert.True(t, result, "Contains should return true when item exists in slice (testing basic functionality)")
assert.Equal(t, 3, count, "should count all occurrences of duplicate item (testing that Contains doesn't stop at first match)")

Implementation Guidelines

Priority Order

1. High: Add testify import statement
2. High: Convert all manual if result != expected checks to assert.Equal(t, expected, result, ...)
3. High: Convert all if !condition checks to assert.True(t, condition, ...)
4. High: Convert all if condition checks to assert.False(t, condition, ...) (where checking for false)
5. Medium: Convert edge case test assertions to testify
6. Low: Consider using assert.Contains / assert.NotContains where semantic

Conversion Pattern

For each table-driven test:

// OLD:
result := FunctionName(tt.input)
if result != tt.expected {
    t.Errorf("FunctionName(...) = %v; want %v", result, tt.expected)
}

// NEW:
result := FunctionName(tt.input)
assert.Equal(t, tt.expected, result, "FunctionName should return expected value")

For each standalone assertion:

// OLD:
if !condition {
    t.Error("message")
}

// NEW:
assert.True(t, condition, "message")

Best Practices from specs/testing.md

• ✅ Use require.* for critical setup (stops test on failure) - not needed in this file since setup is trivial
• ✅ Use assert.* for test validations (continues checking) - primary focus for this refactoring
• ✅ Keep table-driven tests with t.Run() and descriptive names - already excellent
• ✅ No mocks or test suites - test real component interactions - already correct
• ✅ Always include helpful assertion messages - improve with testify syntax

Testing Commands

# Run tests for this file
go test -v ./pkg/sliceutil -run TestContains

# Run all tests in package
go test -v ./pkg/sliceutil

# Run with coverage
go test -cover ./pkg/sliceutil

# Run benchmarks
go test -bench=. ./pkg/sliceutil

# Full test suite
make test-unit

Acceptance Criteria

• Add testify/assert import statement
• Convert all manual if result != expected checks to assert.Equal(t, expected, result, "message")
• Convert all if !condition checks to assert.True(t, condition, "message")
• Convert all negative condition checks to assert.False(t, condition, "message")
• Update all edge case tests to use testify assertions
• All assertion messages are clear and helpful
• Tests pass: go test -v ./pkg/sliceutil
• Code follows patterns in specs/testing.md
• No functional changes - only assertion style updates

Implementation Example

Here's a complete before/after example for one test function:

Before:

func TestContains(t *testing.T) {
    tests := []struct {
        name     string
        slice    []string
        item     string
        expected bool
    }{
        {
            name:     "item exists in slice",
            slice:    []string{"apple", "banana", "cherry"},
            item:     "banana",
            expected: true,
        },
        // ... more test cases
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            result := Contains(tt.slice, tt.item)
            if result != tt.expected {
                t.Errorf("Contains(%v, %q) = %v; want %v", tt.slice, tt.item, result, tt.expected)
            }
        })
    }
}

After:

func TestContains(t *testing.T) {
    tests := []struct {
        name     string
        slice    []string
        item     string
        expected bool
    }{
        {
            name:     "item exists in slice",
            slice:    []string{"apple", "banana", "cherry"},
            item:     "banana",
            expected: true,
        },
        // ... more test cases
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            result := Contains(tt.slice, tt.item)
            assert.Equal(t, tt.expected, result, 
                "Contains should return correct value for slice %v and item %q", tt.slice, tt.item)
        })
    }
}

Additional Context

• Repository Testing Guidelines: See specs/testing.md for comprehensive testing patterns
• Example Tests: Look at recent test files in pkg/workflow/*_test.go for examples of testify usage
• Testify Documentation: https://github.com/stretchr/testify
• Current Test Quality: This file is already well-structured; this refactoring is about modernizing assertion style

---

Priority: Medium
Effort: Small (straightforward find-and-replace pattern across ~20 assertions)
Expected Impact: Improved test failure diagnostics, better alignment with repository standards, clearer error messages for future developers

Files Involved:

• Test file: ./pkg/sliceutil/sliceutil_test.go
• Source file: ./pkg/sliceutil/sliceutil.go

Estimated Time: 15-20 minutes for an experienced developer familiar with testify

AI generated by Daily Testify Uber Super Expert

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