Isolate nested IoC scope bindings

cli/azd/pkg/ioc/container.go

@@ -37,9 +37,11 @@ func NewNestedContainer(parent *NestedContainer) *NestedContainer {
 	current := container.New()
 
 	if parent != nil {
-		// Copy the bindings to the new container
-		// The bindings hold the concrete instance of singleton registrations
-		maps.Copy(current, parent.inner)
+		for registeredType, bindings := range parent.inner {
+			// clone bindings as well, otherwise changes in child scopes will
+			// actually modify the map for the parent!
+			current[registeredType] = maps.Clone(bindings)
+		}
 	}
 
 	instance := &NestedContainer{

cli/azd/pkg/ioc/container_test.go

@@ -165,18 +165,62 @@ func Test_Container_Singleton_Instance_Register_Resolve(t *testing.T) {
 		err = scope1.Resolve(&scope1Instance1)
 		require.NoError(t, err)
 		require.NotNil(t, scope1Instance1)
+		require.Same(t, scope1Instance, scope1Instance1)
 
 		var scope2Instance1 *singletonService
 		err = scope2.Resolve(&scope2Instance1)
 		require.NoError(t, err)
 		require.NotNil(t, scope2Instance1)
-
-		// Instance 1 & 2 are singletons but overriden in each child scope so they should be different
-		require.NotSame(t, rootInstance, rootInstanceResolved)
-		require.NotSame(t, scope1Instance, scope2Instance)
+		require.Same(t, scope2Instance, scope2Instance1)
 	})
 }
 
+func Test_Container_LayerEnvironmentManagerOverridesAreIsolated(t *testing.T) {
+	// This is a case I ran into when I was trying to make it so we could inject a new
+	// environment manager instance for each infra provider. Prior to the fix for this
+	// we'd accidentally end up mutating the _root_ environment manager instead of just the
+	// lower level manager.
+
+	rootContainer := NewNestedContainer(nil)
+	rootEnvManager := &fakeEnvironmentManager{name: "root"}
+	RegisterInstance[environmentManager](rootContainer, rootEnvManager)
+
+	// now we're going to register an env manager, but each one is in a new
+	// scope, so the root should be unaffected (there was a bug where this was
+	// NOT the case)
+	layer1Scope, err := rootContainer.NewScope()
+	require.NoError(t, err)
+	layer1EnvManager := &fakeEnvironmentManager{name: "layer-1"}
+	RegisterInstance[environmentManager](layer1Scope, layer1EnvManager) // override with our own env manager
+
+	layer2Scope, err := rootContainer.NewScope()
+	require.NoError(t, err)
+	layer2EnvManager := &fakeEnvironmentManager{name: "layer-2"}
+	RegisterInstance[environmentManager](layer2Scope, layer2EnvManager) // override with our own env manager
+
+	// okay, at this point we've created this structure in our IoC, each independent from
+	// each other:
+	//
+	// root container
+	// |-- root env manager
+	// |-- layer 1 scope
+	// |   |-- layer 1 env manager
+	// |-- layer 2 scope
+	//     |-- layer 2 env manager
+
+	var resolvedRoot environmentManager
+	require.NoError(t, rootContainer.Resolve(&resolvedRoot))
+	require.Same(t, rootEnvManager, resolvedRoot)
+
+	var resolvedLayer1 environmentManager
+	require.NoError(t, layer1Scope.Resolve(&resolvedLayer1))
+	require.Same(t, layer1EnvManager, resolvedLayer1)
+
+	var resolvedLayer2 environmentManager
+	require.NoError(t, layer2Scope.Resolve(&resolvedLayer2))
+	require.Same(t, layer2EnvManager, resolvedLayer2)
+}
+
 type singletonService struct {
 	timestamp time.Time
 }
@@ -209,6 +253,18 @@ func newTransientService() *transientService {
 
 // ---------- helper types for tests ----------
 
+type environmentManager interface {
+	Name() string
+}
+
+type fakeEnvironmentManager struct {
+	name string
+}
+
+func (m *fakeEnvironmentManager) Name() string {
+	return m.name
+}
+
 type greeter interface {
 	Greet() string
 }
@@ -849,22 +905,39 @@ func Test_DependencyChain(t *testing.T) {
 func Test_NewNestedContainer_InheritsParent(t *testing.T) {
 	t.Parallel()
 
-	parent := NewNestedContainer(nil)
-	parent.MustRegisterSingleton(func() *counterService {
-		return &counterService{calls: 99}
+	t.Run("ParentAccessesFirst", func(t *testing.T) {
+		parent := NewNestedContainer(nil)
+		parent.MustRegisterSingleton(func() *counterService {
+			return &counterService{calls: 99}
+		})
+		child := NewNestedContainer(parent)
+
+		var parentInst *counterService
+		err := parent.Resolve(&parentInst)
+		require.NoError(t, err)
+
+		var childInst *counterService
+		err = child.Resolve(&childInst)
+		require.NoError(t, err)
+		require.Same(t, parentInst, childInst)
 	})
 
-	// Resolve in parent first to cache the singleton
-	var parentInst *counterService
-	err := parent.Resolve(&parentInst)
-	require.NoError(t, err)
+	t.Run("ChildAccessesFirst", func(t *testing.T) {
+		parent := NewNestedContainer(nil)
+		parent.MustRegisterSingleton(func() *counterService {
+			return &counterService{calls: 99}
+		})
+		child := NewNestedContainer(parent)
 
-	child := NewNestedContainer(parent)
-	var childInst *counterService
-	err = child.Resolve(&childInst)
-	require.NoError(t, err)
-	// Child inherits parent's cached singleton
-	require.Same(t, parentInst, childInst)
+		var childInst *counterService
+		err := child.Resolve(&childInst)
+		require.NoError(t, err)
+
+		var parentInst *counterService
+		err = parent.Resolve(&parentInst)
+		require.NoError(t, err)
+		require.Same(t, parentInst, childInst)
+	})
 }
 
 // ---------- inspectResolveError ----------