gt: Generics based Test library for Go

color := "blue"
gt.Value(t, color).Equal("blue")   // Pass
gt.Value(t, color).Equal("orange") // Fail
// gt.Value(t, color).Equal(5)     // Compile error!

import "github.com/gaebalai/gt"

func TestExample(t *testing.T) {
    // Value comparison
    gt.Value(t, user).Equal(expectedUser)

    // Array testing
    gt.Array(t, items).Length(3).Has(expectedItem)

    // Map testing
    gt.Map(t, config).HasKey("database").EqualAt("port", 5432)

    // String testing
    gt.String(t, email).Contains("@").HasSuffix(".com")

    // Number comparison
    gt.Number(t, count).Greater(0).LessOrEqual(100)

    // Error handling
    gt.NoError(t, err).Required()  // Fail fast if error
}

gt.Array(t, users).
    Length(3).
    Has(admin).
    All(func(u User) bool { return u.Active })

gt.NoError(t, err).Required()           // Stop immediately if error
gt.Value(t, config).Required().NotNil() // Stop if nil

gt.Array(t, users).
    Describef("Users for tenant %s", tenantID).
    Length(5)

// Output:
// Users for tenant abc123
// array length is expected to be 5, but actual is 3

// Handle (value, error) returns
result := gt.R1(parseJSON(input)).NoError(t)
gt.Value(t, result.Name).Equal("Alice")

// Test expected errors
gt.R1(parseJSON(badInput)).Error(t).Contains("invalid")

// Good - specialized types give better errors and methods
gt.Array(t, arr).Length(3)
gt.String(t, s).Contains("x")
gt.NoError(t, err)
gt.Number(t, n).Greater(5)

// Avoid - loses specialized functionality
gt.Value(t, len(arr)).Equal(3)
gt.Bool(t, strings.Contains(s, "x")).True()
gt.Value(t, err).Nil()
gt.Bool(t, n > 5).True()

// testify - no compile-time type checking
assert.Equal(t, "hello", 123)  // Compiles but fails at runtime

// gt - caught at compile time
gt.Value(t, "hello").Equal(123)  // Compile error!