feat: added T() method to use generics from forward Assertions

Signed-off-by: Frederic BIDON <fredbi@yahoo.com>

Author: fredbi

assert/assert_adhoc_example_6_test.go

@@ -0,0 +1,35 @@
+// SPDX-FileCopyrightText: Copyright 2025 go-swagger maintainers
+// SPDX-License-Identifier: Apache-2.0
+
+package assert_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/go-openapi/testify/v2/assert"
+)
+
+func ExampleAssertions_with_generics() {
+	t := new(testing.T) // normally provided by test
+
+	a := assert.New(t)
+
+	const expected = "hello"
+	goodValue := "hello"
+	wrongValue := "world"
+
+	r0 := a.Equal(expected, goodValue) // classic reflect-based assertion
+	fmt.Printf("good value is %t\n", r0)
+
+	r1 := assert.EqualT(a.T(), expected, goodValue) // usage with generic assertion
+	fmt.Printf("good value is %t\n", r1)
+
+	r2 := assert.EqualT(a.T(), expected, wrongValue)
+	fmt.Printf("wrong value is %t\n", r2)
+
+	// Output:
+	// good value is true
+	// good value is true
+	// wrong value is false
+}

internal/assertions/assertion.go

@@ -3,7 +3,60 @@
 
 package assertions
 
-// Assertions provides assertion methods around the [T] interface.
+import "context"
+
+var (
+	_ T              = &Assertions{}
+	_ H              = &Assertions{}
+	_ failNower      = &Assertions{}
+	_ namer          = &Assertions{}
+	_ contextualizer = &Assertions{}
+)
+
+// Assertions is the base type to provide assertion methods around the [T] interface.
+//
+// It implements [T] and exposes the other useful methods from [testing.T]:
+// [testing.T.Helper], [testing.T.FailNow] and [testing.T.Context].
+//
+// These methods are optional but useful in this package.
 type Assertions struct {
-	t T //nolint:unused // the internal version of this type doesn't use this field, but generated copies do.
+	t T
+}
+
+func New(t T) *Assertions {
+	return &Assertions{
+		t: t,
+	}
+}
+
+func (a *Assertions) Errorf(format string, args ...any) {
+	a.t.Errorf(format, args...)
+}
+
+func (a *Assertions) Helper() {
+	if h, ok := a.t.(H); ok {
+		h.Helper()
+	}
+}
+
+func (a *Assertions) FailNow() {
+	if f, ok := a.t.(failNower); ok {
+		f.FailNow()
+	}
+}
+
+func (a *Assertions) Name() string {
+	if n, ok := a.t.(namer); ok {
+		return n.Name()
+	}
+
+	return ""
+}
+
+func (a *Assertions) Context() context.Context {
+	if c, ok := a.t.(contextualizer); ok {
+		return c.Context()
+	}
+
+	return context.Background()
 }

internal/assertions/assertion_test.go

@@ -18,4 +18,6 @@ func TestAssertionNew(t *testing.T) {
 	if a.t == nil {
 		FailNow(t, "assertion should contain a T")
 	}
+
+	// TODO: check methods
 }

require/assert_adhoc_example_6_test.go

@@ -0,0 +1,30 @@
+// SPDX-FileCopyrightText: Copyright 2025 go-swagger maintainers
+// SPDX-License-Identifier: Apache-2.0
+
+package require_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/go-openapi/testify/v2/require"
+)
+
+func ExampleAssertions_with_generics() {
+	t := new(testing.T) // normally provided by test
+
+	a := require.New(t)
+
+	const expected = "hello"
+	goodValue := "hello"
+
+	a.Equal(expected, goodValue) // classic reflect-based assertion
+	fmt.Println("good value")
+
+	require.EqualT(a.T(), expected, goodValue) // usage with generic assertion
+	fmt.Println("good value")
+
+	// Output:
+	// good value
+	// good value
+}