feat: add Must and MustV function

Author: smoothprogrammer

README.md

@@ -7,4 +7,4 @@ Package testr provides a minimal extension to the standard library's testing.
 - Minimal assertion API with  `Equal`, `ErrorIs`, `ErrorAs`, and `Panic`.
 - Optional message using `WithMessage`.
 - Stop the execution using `WithFailNow`.
-- Ease of initialization with `Must`.
+- Ease of initialization with `Must` and `MustV`.

example_test.go

@@ -1,9 +1,8 @@
 package testr_test
 
 import (
+	"encoding/json"
 	"fmt"
-	"io"
-	"strings"
 
 	"github.com/minizilla/testr"
 )
@@ -88,10 +87,18 @@ func ExampleWithFailNow() {
 }
 
 func ExampleMust() {
-	r := strings.NewReader("testr")
-	b := testr.Must(io.ReadAll(r))
-	fmt.Println(string(b))
+	var v string
+	testr.Must(json.Unmarshal([]byte(`"testr"`), &v))
+	fmt.Println(v)
 
 	// Output:
 	// testr
 }
+
+func ExampleMustV() {
+	b := testr.MustV(json.Marshal("testr"))
+	fmt.Println(string(b))
+
+	// Output:
+	// "testr"
+}

testr.go

@@ -97,12 +97,23 @@ func (assert *Assertion) Panic(f func(), options ...Option) {
 	f()
 }
 
-// Must is a helper that wraps a call to a function returning (T, error)
+// Must is a helper that wraps a call to a function returning error
 // and panics if the error is non-nil. It is intended for use in variable
 // initializations such as
 //
-//	t := testr.Must(template.New("name").Parse("text"))
-func Must[T any](v T, err error) T {
+//	t := testr.MustV(json.Unmarshal(b, &v))
+func Must(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+// MustV is a helper that wraps a call to a function returning (V, error)
+// and panics if the error is non-nil. It is intended for use in variable
+// initializations such as
+//
+//	t := testr.MustV(json.Marshal(v))
+func MustV[V any](v V, err error) V {
 	if err != nil {
 		panic(err)
 	}

testr_test.go

@@ -353,6 +353,12 @@ func TestNilT(t *testing.T) {
 
 func TestMust(t *testing.T) {
 	assert := testr.New(t)
-	assert.Equal(testr.Must("ok", nil), "ok")
-	assert.Panic(func() { testr.Must("panic", errors.New("intentional error")) })
+	testr.Must(nil)
+	assert.Panic(func() { testr.Must(errors.New("intentional error")) })
+}
+
+func TestMustV(t *testing.T) {
+	assert := testr.New(t)
+	assert.Equal(testr.MustV("ok", nil), "ok")
+	assert.Panic(func() { testr.MustV("panic", errors.New("intentional error")) })
 }