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| 1 | +/* |
| 2 | +Copyright 2022 The Kubernetes Authors. |
| 3 | +
|
| 4 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | +you may not use this file except in compliance with the License. |
| 6 | +You may obtain a copy of the License at |
| 7 | + http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +Unless required by applicable law or agreed to in writing, software |
| 9 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 10 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 11 | +See the License for the specific language governing permissions and |
| 12 | +limitations under the License. |
| 13 | +*/ |
| 14 | + |
| 15 | +package komega |
| 16 | + |
| 17 | +import ( |
| 18 | + "fmt" |
| 19 | + "reflect" |
| 20 | + "strings" |
| 21 | + |
| 22 | + "github.com/google/go-cmp/cmp" |
| 23 | + "github.com/onsi/gomega/format" |
| 24 | + "github.com/onsi/gomega/types" |
| 25 | + "k8s.io/apimachinery/pkg/runtime" |
| 26 | + "k8s.io/apimachinery/pkg/util/sets" |
| 27 | +) |
| 28 | + |
| 29 | +// These package variables hold pre-created commonly used options that can be used to reduce the manual work involved in |
| 30 | +// identifying the paths that need to be compared for testing equality between objects. |
| 31 | +var ( |
| 32 | + // IgnoreAutogeneratedMetadata contains the paths for all the metadata fields that are commonly set by the |
| 33 | + // client and APIServer. This is used as a MatchOption for situations when only user-provided metadata is relevant. |
| 34 | + IgnoreAutogeneratedMetadata = IgnorePaths{ |
| 35 | + "ObjectMeta.UID", |
| 36 | + "ObjectMeta.Generation", |
| 37 | + "ObjectMeta.CreationTimestamp", |
| 38 | + "ObjectMeta.ResourceVersion", |
| 39 | + "ObjectMeta.ManagedFields", |
| 40 | + "ObjectMeta.DeletionGracePeriodSeconds", |
| 41 | + "ObjectMeta.DeletionTimestamp", |
| 42 | + "ObjectMeta.SelfLink", |
| 43 | + "ObjectMeta.GenerateName", |
| 44 | + } |
| 45 | +) |
| 46 | + |
| 47 | +// equalObjectMatcher is a Gomega matcher used to establish equality between two Kubernetes runtime.Objects. |
| 48 | +type equalObjectMatcher struct { |
| 49 | + // original holds the object that will be used to Match. |
| 50 | + original runtime.Object |
| 51 | + |
| 52 | + // diffPaths contains the paths that differ between two objects. |
| 53 | + diffPaths []string |
| 54 | + |
| 55 | + // options holds the options that identify what should and should not be matched. |
| 56 | + options *EqualObjectOptions |
| 57 | +} |
| 58 | + |
| 59 | +// EqualObject returns a Matcher for the passed Kubernetes runtime.Object with the passed Options. This function can be |
| 60 | +// used as a Gomega Matcher in Gomega Assertions. |
| 61 | +func EqualObject(original runtime.Object, opts ...EqualObjectOption) types.GomegaMatcher { |
| 62 | + matchOptions := &EqualObjectOptions{} |
| 63 | + matchOptions = matchOptions.ApplyOptions(opts) |
| 64 | + |
| 65 | + return &equalObjectMatcher{ |
| 66 | + options: matchOptions, |
| 67 | + original: original, |
| 68 | + } |
| 69 | +} |
| 70 | + |
| 71 | +// Match compares the current object to the passed object and returns true if the objects are the same according to |
| 72 | +// the Matcher and MatchOptions. |
| 73 | +func (m *equalObjectMatcher) Match(actual interface{}) (success bool, err error) { |
| 74 | + // Nil checks required first here for: |
| 75 | + // 1) Nil equality which returns true |
| 76 | + // 2) One object nil which returns an error |
| 77 | + actualIsNil := reflect.ValueOf(actual).IsNil() |
| 78 | + originalIsNil := reflect.ValueOf(m.original).IsNil() |
| 79 | + |
| 80 | + if actualIsNil && originalIsNil { |
| 81 | + return true, nil |
| 82 | + } |
| 83 | + if actualIsNil || originalIsNil { |
| 84 | + return false, fmt.Errorf("can not compare an object with a nil. original %v , actual %v", m.original, actual) |
| 85 | + } |
| 86 | + |
| 87 | + m.diffPaths = m.calculateDiff(actual) |
| 88 | + |
| 89 | + return len(m.diffPaths) == 0, nil |
| 90 | +} |
| 91 | + |
| 92 | +// FailureMessage returns a message comparing the full objects after an unexpected failure to match has occurred. |
| 93 | +func (m *equalObjectMatcher) FailureMessage(actual interface{}) (message string) { |
| 94 | + return fmt.Sprintf("the following fields were expected to match but did not:\n%v\n%s", m.diffPaths, |
| 95 | + format.Message(actual, "expected to match", m.original)) |
| 96 | +} |
| 97 | + |
| 98 | +// NegatedFailureMessage returns a string stating that all fields matched, even though that was not expected. |
| 99 | +func (m *equalObjectMatcher) NegatedFailureMessage(actual interface{}) (message string) { |
| 100 | + return fmt.Sprintf("it was expected that some fields do not match, but all of them did") |
| 101 | +} |
| 102 | + |
| 103 | +// diffReporter is a custom recorder for cmp.Diff which records all paths that are |
| 104 | +// different between two objects. |
| 105 | +type diffReporter struct { |
| 106 | + stack []cmp.PathStep |
| 107 | + diffPaths []string |
| 108 | +} |
| 109 | + |
| 110 | +func (r *diffReporter) PushStep(s cmp.PathStep) { |
| 111 | + r.stack = append(r.stack, s) |
| 112 | +} |
| 113 | + |
| 114 | +func (r *diffReporter) Report(res cmp.Result) { |
| 115 | + if !res.Equal() { |
| 116 | + r.diffPaths = append(r.diffPaths, r.currPath()) |
| 117 | + } |
| 118 | +} |
| 119 | + |
| 120 | +func (r *diffReporter) currPath() string { |
| 121 | + p := []string{} |
| 122 | + for _, s := range r.stack[1:] { |
| 123 | + switch s := s.(type) { |
| 124 | + case cmp.StructField, cmp.SliceIndex, cmp.MapIndex: |
| 125 | + p = append(p, s.String()) |
| 126 | + } |
| 127 | + } |
| 128 | + return strings.Join(p, "")[1:] |
| 129 | +} |
| 130 | + |
| 131 | +func (r *diffReporter) PopStep() { |
| 132 | + r.stack = r.stack[:len(r.stack)-1] |
| 133 | +} |
| 134 | + |
| 135 | +// calculateDiff calculates the difference between two objects and returns the |
| 136 | +// paths of the fields that do not match. |
| 137 | +func (m *equalObjectMatcher) calculateDiff(actual interface{}) []string { |
| 138 | + r := diffReporter{} |
| 139 | + cmp.Diff(m.original, actual, cmp.Reporter(&r)) |
| 140 | + return filterDiffPaths(*m.options, r.diffPaths) |
| 141 | +} |
| 142 | + |
| 143 | +// filterDiffPaths filters the diff paths using the paths in EqualObjectOptions. |
| 144 | +func filterDiffPaths(opts EqualObjectOptions, paths []string) []string { |
| 145 | + result := sets.NewString(paths...) |
| 146 | + for _, c := range result.List() { |
| 147 | + if len(opts.matchPaths) > 0 && !matchesAnyPath(c, opts.matchPaths) { |
| 148 | + result.Delete(c) |
| 149 | + continue |
| 150 | + } |
| 151 | + if matchesAnyPath(c, opts.ignorePaths) { |
| 152 | + result.Delete(c) |
| 153 | + } |
| 154 | + } |
| 155 | + return result.List() |
| 156 | +} |
| 157 | + |
| 158 | +// matchesAnyPath returns true if path matches any of the path prefixes. |
| 159 | +// It respects the name boundaries within paths, so 'ObjectMeta.Name' does not |
| 160 | +// match 'ObjectMeta.Namespace' for example. |
| 161 | +func matchesAnyPath(path string, prefixes []string) bool { |
| 162 | + for _, prefix := range prefixes { |
| 163 | + if strings.HasPrefix(path, prefix) { |
| 164 | + rpath := path[len(prefix):] |
| 165 | + // It's a full attribute name if it's a full match, or the next character of the path is |
| 166 | + // either a . or a [ |
| 167 | + if len(rpath) == 0 || rpath[0] == '.' || rpath[0] == '[' { |
| 168 | + return true |
| 169 | + } |
| 170 | + } |
| 171 | + } |
| 172 | + return false |
| 173 | +} |
| 174 | + |
| 175 | +// EqualObjectOption describes an Option that can be applied to a Matcher. |
| 176 | +type EqualObjectOption interface { |
| 177 | + // ApplyToEqualObjectMatcher applies this configuration to the given MatchOption. |
| 178 | + ApplyToEqualObjectMatcher(options *EqualObjectOptions) |
| 179 | +} |
| 180 | + |
| 181 | +// EqualObjectOptions holds the available types of EqualObjectOptions that can be applied to a Matcher. |
| 182 | +type EqualObjectOptions struct { |
| 183 | + ignorePaths []string |
| 184 | + matchPaths []string |
| 185 | +} |
| 186 | + |
| 187 | +// ApplyOptions adds the passed MatchOptions to the MatchOptions struct. |
| 188 | +func (o *EqualObjectOptions) ApplyOptions(opts []EqualObjectOption) *EqualObjectOptions { |
| 189 | + for _, opt := range opts { |
| 190 | + opt.ApplyToEqualObjectMatcher(o) |
| 191 | + } |
| 192 | + return o |
| 193 | +} |
| 194 | + |
| 195 | +// IgnorePaths instructs the Matcher to ignore given paths when computing a diff. |
| 196 | +type IgnorePaths []string |
| 197 | + |
| 198 | +// ApplyToEqualObjectMatcher applies this configuration to the given MatchOptions. |
| 199 | +func (i IgnorePaths) ApplyToEqualObjectMatcher(opts *EqualObjectOptions) { |
| 200 | + opts.ignorePaths = append(opts.ignorePaths, i...) |
| 201 | +} |
| 202 | + |
| 203 | +// MatchPaths instructs the Matcher to restrict its diff to the given paths. If empty the Matcher will look at all paths. |
| 204 | +type MatchPaths []string |
| 205 | + |
| 206 | +// ApplyToEqualObjectMatcher applies this configuration to the given MatchOptions. |
| 207 | +func (i MatchPaths) ApplyToEqualObjectMatcher(opts *EqualObjectOptions) { |
| 208 | + opts.matchPaths = append(opts.matchPaths, i...) |
| 209 | +} |
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