command: Fix terraform show not outputting child_modules properly in certain circumstances

command/jsonstate/state.go

@@ -198,14 +198,30 @@ func marshalRootModule(s *states.State, schemas *terraform.Schemas) (module, err
  return ret, err
  }
 
- // build a map of module -> [child module addresses]
- moduleMap := make(map[string][]addrs.ModuleInstance)
+ // build a map of module -> set[child module addresses]
+ moduleChildSet := make(map[string]map[string]struct{})
  for _, mod := range s.Modules {
  if mod.Addr.IsRoot() {
  continue
  } else {
- parent := mod.Addr.Parent().String()
- moduleMap[parent] = append(moduleMap[parent], mod.Addr)
+ for childAddr := mod.Addr; !childAddr.IsRoot(); childAddr = childAddr.Parent() {
+ if _, ok := moduleChildSet[childAddr.Parent().String()]; !ok {
+ moduleChildSet[childAddr.Parent().String()] = map[string]struct{}{}
+ }
+ moduleChildSet[childAddr.Parent().String()][childAddr.String()] = struct{}{}
+ }
+ }
+ }
+
+ // transform the previous map into map of module -> [child module addresses]
+ moduleMap := make(map[string][]addrs.ModuleInstance)
+ for parent, children := range moduleChildSet {
+ for child := range children {
+ childModuleInstance, diags := addrs.ParseModuleInstanceStr(child)
+ if diags.HasErrors() {
+ return ret, diags.Err()
+ }
+ moduleMap[parent] = append(moduleMap[parent], childModuleInstance)
  }
  }
 
@@ -224,14 +240,19 @@ func marshalModules(
 ) ([]module, error) {
  var ret []module
  for _, child := range modules {
- stateMod := s.Module(child)
  // cm for child module, naming things is hard.
- cm := module{Address: stateMod.Addr.String()}
- rs, err := marshalResources(stateMod.Resources, stateMod.Addr, schemas)
- if err != nil {
- return nil, err
+ cm := module{Address: child.String()}
+
+ // the module may be resourceless and contain only submodules, it will then be nil here
+ stateMod := s.Module(child)
+ if stateMod != nil {
+ rs, err := marshalResources(stateMod.Resources, stateMod.Addr, schemas)
+ if err != nil {
+ return nil, err
+ }
+ cm.Resources = rs
  }
- cm.Resources = rs
+
  if moduleMap[child.String()] != nil {
  moreChildModules, err := marshalModules(s, schemas, moduleMap[child.String()], moduleMap)
  if err != nil {

command/jsonstate/state_test.go

@@ -554,6 +554,59 @@ func TestMarshalModules_nested(t *testing.T) {
  }
 }
 
+func TestMarshalModules_parent_no_resources(t *testing.T) {
+ subModule, _ := addrs.ParseModuleInstanceStr("module.child.module.submodule")
+ testState := states.BuildState(func(s *states.SyncState) {
+ s.SetResourceInstanceCurrent(
+ addrs.Resource{
+ Mode: addrs.ManagedResourceMode,
+ Type: "test_instance",
+ Name: "foo",
+ }.Instance(addrs.NoKey).Absolute(addrs.RootModuleInstance),
+ &states.ResourceInstanceObjectSrc{
+ AttrsJSON: []byte(`{"id":"bar","foo":"value","bar":"value"}`),
+ Status: states.ObjectReady,
+ },
+ addrs.AbsProviderConfig{
+ Provider: addrs.NewDefaultProvider("test"),
+ Module: addrs.RootModule,
+ },
+ )
+ s.SetResourceInstanceCurrent(
+ addrs.Resource{
+ Mode: addrs.ManagedResourceMode,
+ Type: "test_instance",
+ Name: "foo",
+ }.Instance(addrs.NoKey).Absolute(subModule),
+ &states.ResourceInstanceObjectSrc{
+ AttrsJSON: []byte(`{"id":"foo","foo":"value","bar":"value"}`),
+ Status: states.ObjectReady,
+ },
+ addrs.AbsProviderConfig{
+ Provider: addrs.NewDefaultProvider("test"),
+ Module: subModule.Module(),
+ },
+ )
+ })
+ got, err := marshalRootModule(testState, testSchemas())
+
+ if err != nil {
+ t.Fatalf("unexpected error: %s", err.Error())
+ }
+
+ if len(got.ChildModules) != 1 {
+ t.Fatalf("wrong result! got %d modules, expected 1", len(got.ChildModules))
+ }
+
+ if got.ChildModules[0].Address != "module.child" {
+ t.Fatalf("wrong result! got %#v\n", got)
+ }
+
+ if got.ChildModules[0].ChildModules[0].Address != "module.child.module.submodule" {
+ t.Fatalf("wrong result! got %#v\n", got)
+ }
+}
+
 func testSchemas() *terraform.Schemas {
  return &terraform.Schemas{
  Providers: map[addrs.Provider]*terraform.ProviderSchema{