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encoding/openapi: detect cycles when expanding references
Fixes #915
Change-Id: Ie781ee316e8675da66f7ca3bea4c841acaaa8a5b
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/9603
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
+185
-64
+16
-3
encoding/openapi/build.go
+16
-3
encoding/openapi/build.go
···
36
36
instExt *cue.Instance
37
37
refPrefix string
38
38
path []string
39
+
errs errors.Error
39
40
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41
expandRefs bool
41
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structural bool
···
49
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50
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// Track external schemas.
51
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externalRefs map[string]*externalType
53
+
54
+
// Used for cycle detection in case of using ExpandReferences. At the
55
+
// moment, CUE does not detect cycles when a user forcefully steps into a
56
+
// pattern constraint.
57
+
//
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+
// TODO: consider an option in the CUE API where optional fields are
59
+
// recursively evaluated.
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+
cycleNodes []*adt.Vertex
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}
53
62
54
63
type externalType struct {
···
168
177
return x < y
169
178
})
170
179
171
-
return (*ast.StructLit)(c.schemas), nil
180
+
return (*ast.StructLit)(c.schemas), c.errs
172
181
}
173
182
174
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func (c *buildContext) build(name string, v cue.Value) *ast.StructLit {
···
314
323
}
315
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316
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func (b *builder) value(v cue.Value, f typeFunc) (isRef bool) {
326
+
b.pushNode(v)
327
+
defer b.popNode()
328
+
317
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count := 0
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disallowDefault := false
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var values cue.Value
···
770
782
b.setSingle("properties", (*ast.StructLit)(properties), false)
771
783
}
772
784
773
-
if t, ok := v.Elem(); ok && (b.core == nil || b.core.items == nil) {
785
+
if t, ok := v.Elem(); ok &&
786
+
(b.core == nil || b.core.items == nil) && b.checkCycle(t) {
774
787
schema := b.schema(nil, "*", t)
775
788
if len(schema.Elts) > 0 {
776
789
b.setSingle("additionalProperties", schema, true) // Not allowed in structural.
···
871
884
}
872
885
873
886
if !hasMax || int64(len(items)) < maxLength {
874
-
if typ, ok := v.Elem(); ok {
887
+
if typ, ok := v.Elem(); ok && b.checkCycle(typ) {
875
888
var core *builder
876
889
if b.core != nil {
877
890
core = b.core.items
+9
encoding/openapi/crd.go
+9
encoding/openapi/crd.go
···
109
109
// To this extent, all fields of both conjunctions and disjunctions are
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// collected in a single properties map.
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func (b *builder) buildCore(v cue.Value) {
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+
b.pushNode(v)
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+
defer b.popNode()
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+
112
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if !b.ctx.expandRefs {
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_, r := v.Reference()
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if len(r) > 0 {
···
126
129
switch b.kind {
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130
case cue.StructKind:
128
131
if typ, ok := v.Elem(); ok {
132
+
if !b.checkCycle(typ) {
133
+
return
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+
}
129
135
if b.items == nil {
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b.items = newCoreBuilder(b.ctx)
131
137
}
···
135
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136
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case cue.ListKind:
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if typ, ok := v.Elem(); ok {
144
+
if !b.checkCycle(typ) {
145
+
return
146
+
}
138
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if b.items == nil {
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b.items = newCoreBuilder(b.ctx)
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}
+59
encoding/openapi/cycle.go
+59
encoding/openapi/cycle.go
···
1
+
// Copyright 2021 CUE Authors
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+
//
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+
// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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+
//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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+
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+
package openapi
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+
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+
import (
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+
"cuelang.org/go/cue"
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+
"cuelang.org/go/cue/errors"
20
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"cuelang.org/go/cue/token"
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+
"cuelang.org/go/internal/core/dep"
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+
"cuelang.org/go/internal/core/eval"
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+
internalvalue "cuelang.org/go/internal/value"
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+
)
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+
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+
func (b *builder) pushNode(v cue.Value) {
27
+
_, n := internalvalue.ToInternal(v)
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+
b.ctx.cycleNodes = append(b.ctx.cycleNodes, n)
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+
}
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+
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+
func (b *builder) popNode() {
32
+
b.ctx.cycleNodes = b.ctx.cycleNodes[:len(b.ctx.cycleNodes)-1]
33
+
}
34
+
35
+
func (b *builder) checkCycle(v cue.Value) bool {
36
+
if !b.ctx.expandRefs {
37
+
return true
38
+
}
39
+
r, n := internalvalue.ToInternal(v)
40
+
ctx := eval.NewContext(r, n)
41
+
42
+
err := dep.Visit(ctx, n, func(d dep.Dependency) error {
43
+
for _, m := range b.ctx.cycleNodes {
44
+
if m == d.Node {
45
+
var p token.Pos
46
+
if src := d.Node.Source(); src != nil {
47
+
p = src.Pos()
48
+
}
49
+
err := errors.Newf(p,
50
+
"cycle in reference at %v: cyclic structures not allowed when reference expansion is requested", v.Path())
51
+
b.ctx.errs = errors.Append(b.ctx.errs, err)
52
+
return err
53
+
}
54
+
}
55
+
return nil
56
+
})
57
+
58
+
return err == nil
59
+
}
+80
-61
encoding/openapi/openapi_test.go
+80
-61
encoding/openapi/openapi_test.go
···
43
43
testCases := []struct {
44
44
in, out string
45
45
config *openapi.Config
46
+
err string
46
47
}{{
47
-
"structural.cue",
48
-
"structural.json",
49
-
resolveRefs,
48
+
in: "structural.cue",
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+
out: "structural.json",
50
+
config: resolveRefs,
50
51
}, {
51
-
"nested.cue",
52
-
"nested.json",
53
-
defaultConfig,
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+
in: "nested.cue",
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+
out: "nested.json",
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+
config: defaultConfig,
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}, {
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-
"simple.cue",
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-
"simple.json",
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-
resolveRefs,
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+
in: "simple.cue",
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+
out: "simple.json",
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+
config: resolveRefs,
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}, {
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-
"simple.cue",
60
-
"simple-filter.json",
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&openapi.Config{Info: info, FieldFilter: "min.*|max.*"},
60
+
in: "simple.cue",
61
+
out: "simple-filter.json",
62
+
config: &openapi.Config{Info: info, FieldFilter: "min.*|max.*"},
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}, {
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-
"array.cue",
64
-
"array.json",
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-
defaultConfig,
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+
in: "array.cue",
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+
out: "array.json",
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+
config: defaultConfig,
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}, {
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-
"enum.cue",
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-
"enum.json",
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-
defaultConfig,
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+
in: "enum.cue",
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+
out: "enum.json",
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+
config: defaultConfig,
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}, {
71
-
"struct.cue",
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-
"struct.json",
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-
defaultConfig,
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+
in: "struct.cue",
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+
out: "struct.json",
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+
config: defaultConfig,
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}, {
75
-
"strings.cue",
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"strings.json",
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-
defaultConfig,
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+
in: "strings.cue",
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+
out: "strings.json",
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+
config: defaultConfig,
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}, {
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-
"nums.cue",
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-
"nums.json",
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-
defaultConfig,
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+
in: "nums.cue",
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+
out: "nums.json",
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+
config: defaultConfig,
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}, {
83
-
"nums.cue",
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"nums-v3.1.0.json",
85
-
&openapi.Config{Info: info, Version: "3.1.0"},
84
+
in: "nums.cue",
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+
out: "nums-v3.1.0.json",
86
+
config: &openapi.Config{Info: info, Version: "3.1.0"},
86
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}, {
87
-
"builtins.cue",
88
-
"builtins.json",
89
-
defaultConfig,
88
+
in: "builtins.cue",
89
+
out: "builtins.json",
90
+
config: defaultConfig,
90
91
}, {
91
-
"oneof.cue",
92
-
"oneof.json",
93
-
defaultConfig,
92
+
in: "oneof.cue",
93
+
out: "oneof.json",
94
+
config: defaultConfig,
94
95
}, {
95
-
"oneof.cue",
96
-
"oneof-resolve.json",
97
-
resolveRefs,
96
+
in: "oneof.cue",
97
+
out: "oneof-resolve.json",
98
+
config: resolveRefs,
98
99
}, {
99
-
"openapi.cue",
100
-
"openapi.json",
101
-
defaultConfig,
100
+
in: "openapi.cue",
101
+
out: "openapi.json",
102
+
config: defaultConfig,
102
103
}, {
103
-
"openapi.cue",
104
-
"openapi-norefs.json",
105
-
resolveRefs,
104
+
in: "openapi.cue",
105
+
out: "openapi-norefs.json",
106
+
config: resolveRefs,
106
107
}, {
107
-
"oneof.cue",
108
-
"oneof-funcs.json",
109
-
&openapi.Config{
108
+
in: "oneof.cue",
109
+
out: "oneof-funcs.json",
110
+
config: &openapi.Config{
110
111
Info: info,
111
112
ReferenceFunc: func(inst *cue.Instance, path []string) string {
112
113
return strings.ToUpper(strings.Join(path, "_"))
···
116
117
},
117
118
},
118
119
}, {
119
-
"refs.cue",
120
-
"refs.json",
121
-
&openapi.Config{
120
+
in: "refs.cue",
121
+
out: "refs.json",
122
+
config: &openapi.Config{
122
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Info: info,
123
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ReferenceFunc: func(inst *cue.Instance, path []string) string {
124
125
switch {
···
129
130
},
130
131
},
131
132
}, {
132
-
"issue131.cue",
133
-
"issue131.json",
134
-
&openapi.Config{Info: info, SelfContained: true},
133
+
in: "issue131.cue",
134
+
out: "issue131.json",
135
+
config: &openapi.Config{Info: info, SelfContained: true},
136
+
}, {
137
+
// Issue #915
138
+
in: "cycle.cue",
139
+
out: "cycle.json",
140
+
config: &openapi.Config{Info: info},
141
+
}, {
142
+
// Issue #915
143
+
in: "cycle.cue",
144
+
config: &openapi.Config{Info: info, ExpandReferences: true},
145
+
err: "cycle",
135
146
}}
136
147
for _, tc := range testCases {
137
148
t.Run(tc.out, func(t *testing.T) {
···
144
155
t.Fatal(errors.Details(inst.Err, nil))
145
156
}
146
157
147
-
all, err := tc.config.All(inst)
158
+
b, err := openapi.Gen(inst, tc.config)
148
159
if err != nil {
149
-
t.Fatal(err)
160
+
if tc.err == "" {
161
+
t.Fatal("unexpected error:", errors.Details(inst.Err, nil))
162
+
}
163
+
return
150
164
}
151
-
walk(all)
152
165
153
-
b, err := openapi.Gen(inst, tc.config)
154
-
if err != nil {
155
-
t.Fatal(err)
166
+
if tc.err != "" {
167
+
t.Fatal("unexpected success:", tc.err)
168
+
} else {
169
+
all, err := tc.config.All(inst)
170
+
if err != nil {
171
+
t.Fatal(err)
172
+
}
173
+
walk(all)
156
174
}
175
+
157
176
var out = &bytes.Buffer{}
158
177
_ = json.Indent(out, b, "", " ")
159
178
···
206
225
ExpandReferences: true,
207
226
})
208
227
if err != nil {
209
-
t.Fatal(err)
228
+
t.Fatal(errors.Details(err, nil))
210
229
}
211
230
212
231
var out = &bytes.Buffer{}
+19
encoding/openapi/testdata/cycle.json
+19
encoding/openapi/testdata/cycle.json
···
1
+
{
2
+
"openapi": "3.0.0",
3
+
"info": {
4
+
"title": "test",
5
+
"version": "v1"
6
+
},
7
+
"paths": {},
8
+
"components": {
9
+
"schemas": {
10
+
"Foo": {
11
+
"description": "Issue #915",
12
+
"type": "object",
13
+
"additionalProperties": {
14
+
"$ref": "#/components/schemas/Foo"
15
+
}
16
+
}
17
+
}
18
+
}
19
+
}