Simplify code base.

- In ResMap, drop concept of internal Id to Resource
   map.  The ResMap is now (just) a list, allowing only
   very particular edits.

 - Resources should now be maintained in the order
   loaded.  A later PR can adjust tests to remove the
   internal legacy sorting, and confirm order-out is
   predictable from order-in.  The PR would suppress
   the sort in tests, and reorder the output to make
   all tests pass again, and confirm that the new order
   matched depth-first input traversal.  The FromMap
   fixture function was removed from all test inputs to
   establish a predictable input order.

 - Resources now have two 'Ids', OriginalId and
   CurrentId.  The former is fixed as
   GVK-name-namespace at load time, the latter changes
   during transformations.  The latter can be used to
   narrow name references when the former maps to
   multiple resources.  We allow bases to be loaded
   more than once in a build (a diamond pattern), so
   the OriginalId is not unique across the resources
   set.  The CurrentId is (and must be) unique, but is
   constantly mutating.  Failing to make this
   distinction clear, and attempting to maintain a
   mapping from a single mutating Id to a resource was
   making the code too complex.

 - Drop prefix/suffix from ResId - the ResId is now
   immutable.  A later PR can remove the distinction
   with ItemId.

 - This PR increases coverage of ResMap is since this
   is a large refactor.  Higher level tests didn't need
   much change outside reordering of results at the
   resource level.

pkg/resource/resource.go

@@ -1,18 +1,5 @@
-/*
-Copyright 2018 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 // Package resource implements representations of k8s API resources as "unstructured" objects.
 package resource
@@ -36,6 +23,8 @@ type Resource struct {
 	options      *types.GenArgs
 	refBy        []resid.ResId
 	refVarNames  []string
+	namePrefixes []string
+	nameSuffixes []string
 }
 
 // DeepCopy returns a new copy of resource
@@ -61,7 +50,33 @@ func (r *Resource) copyOtherFields(other *Resource) {
 	r.originalNs = other.originalNs
 	r.options = other.options
 	r.refBy = other.copyRefBy()
-	r.refVarNames = other.copyRefVarNames()
+	r.refVarNames = copyStringSlice(other.refVarNames)
+	r.namePrefixes = copyStringSlice(other.namePrefixes)
+	r.nameSuffixes = copyStringSlice(other.nameSuffixes)
+}
+
+func (r *Resource) Equals(o *Resource) bool {
+	return r.ReferencesEqual(o) &&
+		reflect.DeepEqual(r.Kunstructured, o.Kunstructured)
+}
+
+func (r *Resource) ReferencesEqual(o *Resource) bool {
+	setSelf := make(map[resid.ResId]bool)
+	setOther := make(map[resid.ResId]bool)
+	for _, ref := range o.refBy {
+		setOther[ref] = true
+	}
+	for _, ref := range r.refBy {
+		if _, ok := setOther[ref]; !ok {
+			return false
+		}
+		setSelf[ref] = true
+	}
+	return len(setSelf) == len(setOther)
+}
+
+func (r *Resource) KunstructEqual(o *Resource) bool {
+	return reflect.DeepEqual(r.Kunstructured, o.Kunstructured)
 }
 
 // Merge performs merge with other resource.
@@ -71,23 +86,49 @@ func (r *Resource) Merge(other *Resource) {
 }
 
 func (r *Resource) copyRefBy() []resid.ResId {
+	if r.refBy == nil {
+		return nil
+	}
 	s := make([]resid.ResId, len(r.refBy))
 	copy(s, r.refBy)
 	return s
 }
 
-func (r *Resource) copyRefVarNames() []string {
-	s := make([]string, len(r.refVarNames))
-	copy(s, r.refVarNames)
-	return s
+func copyStringSlice(s []string) []string {
+	if s == nil {
+		return nil
+	}
+	c := make([]string, len(s))
+	copy(c, s)
+	return c
+}
+
+func (r *Resource) AddNamePrefix(p string) {
+	r.namePrefixes = append(r.namePrefixes, p)
+}
+
+func (r *Resource) AddNameSuffix(s string) {
+	r.nameSuffixes = append(r.nameSuffixes, s)
+}
+
+func (r *Resource) GetOutermostNamePrefix() string {
+	if len(r.namePrefixes) == 0 {
+		return ""
+	}
+	return r.namePrefixes[len(r.namePrefixes)-1]
+}
+
+func (r *Resource) GetOutermostNameSuffix() string {
+	if len(r.nameSuffixes) == 0 {
+		return ""
+	}
+	return r.nameSuffixes[len(r.nameSuffixes)-1]
 }
 
 func (r *Resource) InSameFuzzyNamespace(o *Resource) bool {
-	return r.GetNamespace() == o.GetNamespace()
-}
-
-func (r *Resource) KunstructEqual(o *Resource) bool {
-	return reflect.DeepEqual(r.Kunstructured, o.Kunstructured)
+	return r.GetNamespace() == o.GetNamespace() &&
+		r.GetOutermostNamePrefix() == o.GetOutermostNamePrefix() &&
+		r.GetOutermostNameSuffix() == o.GetOutermostNameSuffix()
 }
 
 func (r *Resource) GetOriginalName() string {
@@ -146,14 +187,18 @@ func (r *Resource) GetNamespace() string {
 	return namespace
 }
 
-// Id returns the immutable ResId for the resource.
-func (r *Resource) Id() resid.ResId {
+// OrgId returns the original, immutable ResId for the resource.
+// This doesn't have to be unique in a ResMap.
+// TODO: compute this once and save it in the resource.
+func (r *Resource) OrgId() resid.ResId {
 	return resid.NewResIdWithNamespace(
 		r.GetGvk(), r.GetOriginalName(), r.GetOriginalNs())
 }
 
-// FinalId returns a ResId for the resource using the mutable bits.
-func (r *Resource) FinalId() resid.ResId {
+// CurId returns a ResId for the resource using the
+// mutable parts of the resource.
+// This should be unique in any ResMap.
+func (r *Resource) CurId() resid.ResId {
 	return resid.NewResIdWithNamespace(
 		r.GetGvk(), r.GetName(), r.GetNamespace())
 }