internal/stub: move from container

This package solves a very specific stubbing use case, in a less than elegant manner.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/stub/exit_test.go

@@ -0,0 +1,111 @@
+package stub_test
+
+import (
+	"testing"
+	_ "unsafe" // for go:linkname
+
+	"hakurei.app/internal/stub"
+)
+
+// Made available here to check panic recovery behaviour.
+//
+//go:linkname handleExitNew hakurei.app/internal/stub.handleExitNew
+func handleExitNew(t testing.TB)
+
+// overrideTFailNow overrides the Fail and FailNow method.
+type overrideTFailNow struct {
+	*testing.T
+	failNow bool
+	fail    bool
+}
+
+func (o *overrideTFailNow) FailNow() {
+	if o.failNow {
+		o.Errorf("attempted to FailNow twice")
+	}
+	o.failNow = true
+}
+
+func (o *overrideTFailNow) Fail() {
+	if o.fail {
+		o.Errorf("attempted to Fail twice")
+	}
+	o.fail = true
+}
+
+func TestHandleExit(t *testing.T) {
+	t.Parallel()
+
+	t.Run("exit", func(t *testing.T) {
+		t.Parallel()
+		defer stub.HandleExit(t)
+		panic(stub.PanicExit)
+	})
+
+	t.Run("goexit", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("FailNow", func(t *testing.T) {
+			t.Parallel()
+
+			ot := &overrideTFailNow{T: t}
+			defer func() {
+				if !ot.failNow {
+					t.Errorf("FailNow was never called")
+				}
+			}()
+			defer stub.HandleExit(ot)
+			panic(0xcafe0)
+		})
+
+		t.Run("Fail", func(t *testing.T) {
+			t.Parallel()
+
+			ot := &overrideTFailNow{T: t}
+			defer func() {
+				if !ot.fail {
+					t.Errorf("Fail was never called")
+				}
+			}()
+			defer handleExitNew(ot)
+			panic(0xcafe0)
+		})
+	})
+
+	t.Run("nil", func(t *testing.T) {
+		t.Parallel()
+		defer stub.HandleExit(t)
+	})
+
+	t.Run("passthrough", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("toplevel", func(t *testing.T) {
+			t.Parallel()
+
+			defer func() {
+				want := 0xcafe
+				if r := recover(); r != want {
+					t.Errorf("recover: %v, want %v", r, want)
+				}
+
+			}()
+			defer stub.HandleExit(t)
+			panic(0xcafe)
+		})
+
+		t.Run("new", func(t *testing.T) {
+			t.Parallel()
+
+			defer func() {
+				want := 0xcafe
+				if r := recover(); r != want {
+					t.Errorf("recover: %v, want %v", r, want)
+				}
+
+			}()
+			defer handleExitNew(t)
+			panic(0xcafe)
+		})
+	})
+}