add extensions/globals package (#692)

this package can be used to reset the global state of ginkgo

extensions/globals/globals.go

@@ -0,0 +1,26 @@
+// Package `globals` provides an interface to alter the global state of ginkgo suite.
+//
+// ginkgo currently registers a few singleton global vars that hold all the
+// test blocks and failure management. These vars are global per package, which means
+// that only one Suite definition can coexist in one package.
+//
+// However, there can be some use cases where applications using ginkgo may want to
+// have a bit more control about this. For instance, a package may be using ginkgo
+// to dynamically generate different tests and groups depending on some configuration.
+// In this particular case, if the application wants to test how these different groups
+// are generated, they will need access to change these global variables, so they
+// can re-generate this global state, and ensure that different configuration generate
+// indeed different tests.
+//
+// Note that this package is not intended to be used as part of normal ginkgo setups, and
+// usually, you will never need to worry about the global state of ginkgo
+package globals
+
+import "github.com/onsi/ginkgo/internal/global"
+
+// Reset calls `global.InitializeGlobals()` which will basically create a new instance
+// of Suite, and therefore, will effectively reset the global variables to the init state.
+// This will effectively remove all groups, tests and blocks that were added to the Suite.
+func Reset() {
+	global.InitializeGlobals()
+}

extensions/globals/globals_test.go

@@ -0,0 +1,43 @@
+package globals_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	"github.com/onsi/ginkgo/extensions/globals"
+	. "github.com/onsi/gomega"
+)
+
+func TestGlobals(t *testing.T) {
+	RegisterFailHandler(Fail)
+
+	// define some vars to store how many times a test has been run
+	var (
+		testI  = 0
+		testII = 0
+	)
+
+	// Define a simple gingko test I
+	var _ = Describe("ginkgo test I", func() {
+		It("build tests I", func() {
+			testI++
+			Ω(testI).Should(Equal(1))
+		})
+	})
+
+	RunSpecs(t, "Test Runner Suite I")
+
+	// reset the global state of ginkgo. test I should now be removed, and it
+	// won't run twice.
+	globals.Reset()
+
+	// Define a simple gingko test II
+	var _ = Describe("ginkgo test II", func() {
+		It("build tests II", func() {
+			testII++
+			Ω(testII).Should(Equal(1))
+		})
+	})
+
+	RunSpecs(t, "Test Runner Suite II")
+}

internal/global/init.go

@@ -13,6 +13,10 @@ var Suite *suite.Suite
 var Failer *failer.Failer
 
 func init() {
+	InitializeGlobals()
+}
+
+func InitializeGlobals() {
 	Failer = failer.New()
 	Suite = suite.New(Failer)
 }