jsonschema: add more schema fields
Add additional fields to Schema which are mentioned in the spec but
do not affect validation.
Change-Id: I89488261a00c207d01cd7fc59d782f43692fe528
Reviewed-on: https://go-review.googlesource.com/c/tools/+/674976
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Jonathan Amsterdam <jba@google.com>
diff --git a/internal/mcp/jsonschema/resolve.go b/internal/mcp/jsonschema/resolve.go
index f82eec1..d28fba4 100644
--- a/internal/mcp/jsonschema/resolve.go
+++ b/internal/mcp/jsonschema/resolve.go
@@ -153,6 +153,14 @@
// TODO: validate the schema's properties,
// ideally by jsonschema-validating it against the meta-schema.
+ // Some properties are present so that Schemas can round-trip, but we do not
+ // validate them.
+ // Currently, it's just the $vocabulary property.
+ // As a special case, we can validate the 2020-12 meta-schema.
+ if s.Vocabulary != nil && s.Schema != draft202012 {
+ addf("cannot validate a schema with $vocabulary")
+ }
+
// Check and compile regexps.
if s.Pattern != "" {
re, err := regexp.Compile(s.Pattern)
diff --git a/internal/mcp/jsonschema/schema.go b/internal/mcp/jsonschema/schema.go
index 1ec4b0d..d6d5f76 100644
--- a/internal/mcp/jsonschema/schema.go
+++ b/internal/mcp/jsonschema/schema.go
@@ -58,6 +58,11 @@
// metadata
Title string `json:"title,omitempty"`
Description string `json:"description,omitempty"`
+ Default *any `json:"default,omitempty"`
+ Deprecated bool `json:"deprecated,omitempty"`
+ ReadOnly bool `json:"readOnly,omitempty"`
+ WriteOnly bool `json:"writeOnly,omitempty"`
+ Examples []any `json:"examples,omitempty"`
// validation
// Use Type for a single type, or Types for multiple types; never both.
@@ -110,6 +115,15 @@
Else *Schema `json:"else,omitempty"`
DependentSchemas map[string]*Schema `json:"dependentSchemas,omitempty"`
+ // other
+ // https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.8
+ ContentEncoding string `json:"contentEncoding,omitempty"`
+ ContentMediaType string `json:"contentMediaType,omitempty"`
+ ContentSchema *Schema `json:"contentSchema,omitempty"`
+
+ // https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.7
+ Format string `json:"format,omitempty"`
+
// computed fields
// This schema's base schema.
@@ -237,6 +251,7 @@
ms := struct {
Type json.RawMessage `json:"type,omitempty"`
Const json.RawMessage `json:"const,omitempty"`
+ Default json.RawMessage `json:"default,omitempty"`
MinLength *integer `json:"minLength,omitempty"`
MaxLength *integer `json:"maxLength,omitempty"`
MinItems *integer `json:"minItems,omitempty"`
@@ -269,14 +284,24 @@
return err
}
- // Setting Const to a pointer to null will marshal properly, but won't unmarshal:
- // the *any is set to nil, not a pointer to nil.
- if len(ms.Const) > 0 {
- if bytes.Equal(ms.Const, []byte("null")) {
- s.Const = new(any)
- } else if err := json.Unmarshal(ms.Const, &s.Const); err != nil {
- return err
+ unmarshalAnyPtr := func(p **any, raw json.RawMessage) error {
+ if len(raw) == 0 {
+ return nil
}
+ if bytes.Equal(raw, []byte("null")) {
+ *p = new(any)
+ return nil
+ }
+ return json.Unmarshal(raw, p)
+ }
+
+ // Setting Const or Default to a pointer to null will marshal properly, but won't
+ // unmarshal: the *any is set to nil, not a pointer to nil.
+ if err := unmarshalAnyPtr(&s.Const, ms.Const); err != nil {
+ return err
+ }
+ if err := unmarshalAnyPtr(&s.Default, ms.Default); err != nil {
+ return err
}
set := func(dst **int, src *integer) {
diff --git a/internal/mcp/jsonschema/schema_test.go b/internal/mcp/jsonschema/schema_test.go
index 4d042d5..8394bb5 100644
--- a/internal/mcp/jsonschema/schema_test.go
+++ b/internal/mcp/jsonschema/schema_test.go
@@ -24,6 +24,7 @@
{Const: Ptr(any(nil))},
{Const: Ptr(any([]int{}))},
{Const: Ptr(any(map[string]any{}))},
+ {Default: Ptr(any(nil))},
} {
data, err := json.Marshal(s)
if err != nil {
@@ -31,9 +32,7 @@
}
t.Logf("marshal: %s", data)
var got *Schema
- if err := json.Unmarshal(data, &got); err != nil {
- t.Fatal(err)
- }
+ mustUnmarshal(t, data, &got)
if !Equal(got, s) {
t.Errorf("got %+v, want %+v", got, s)
if got.Const != nil && s.Const != nil {
@@ -68,9 +67,7 @@
{`{"unk":0}`, `{}`}, // unknown fields are dropped, unfortunately
} {
var s Schema
- if err := json.Unmarshal([]byte(tt.in), &s); err != nil {
- t.Fatal(err)
- }
+ mustUnmarshal(t, []byte(tt.in), &s)
data, err := json.Marshal(s)
if err != nil {
t.Fatal(err)
@@ -126,3 +123,10 @@
t.Errorf("got %d, want %d", got, want)
}
}
+
+func mustUnmarshal(t *testing.T, data []byte, ptr any) {
+ t.Helper()
+ if err := json.Unmarshal(data, ptr); err != nil {
+ t.Fatal(err)
+ }
+}
diff --git a/internal/mcp/jsonschema/testdata/draft2020-12/default.json b/internal/mcp/jsonschema/testdata/draft2020-12/default.json
new file mode 100644
index 0000000..ceb3ae2
--- /dev/null
+++ b/internal/mcp/jsonschema/testdata/draft2020-12/default.json
@@ -0,0 +1,82 @@
+[
+ {
+ "description": "invalid type for default",
+ "schema": {
+ "$schema": "https://json-schema.org/draft/2020-12/schema",
+ "properties": {
+ "foo": {
+ "type": "integer",
+ "default": []
+ }
+ }
+ },
+ "tests": [
+ {
+ "description": "valid when property is specified",
+ "data": {"foo": 13},
+ "valid": true
+ },
+ {
+ "description": "still valid when the invalid default is used",
+ "data": {},
+ "valid": true
+ }
+ ]
+ },
+ {
+ "description": "invalid string value for default",
+ "schema": {
+ "$schema": "https://json-schema.org/draft/2020-12/schema",
+ "properties": {
+ "bar": {
+ "type": "string",
+ "minLength": 4,
+ "default": "bad"
+ }
+ }
+ },
+ "tests": [
+ {
+ "description": "valid when property is specified",
+ "data": {"bar": "good"},
+ "valid": true
+ },
+ {
+ "description": "still valid when the invalid default is used",
+ "data": {},
+ "valid": true
+ }
+ ]
+ },
+ {
+ "description": "the default keyword does not do anything if the property is missing",
+ "schema": {
+ "$schema": "https://json-schema.org/draft/2020-12/schema",
+ "type": "object",
+ "properties": {
+ "alpha": {
+ "type": "number",
+ "maximum": 3,
+ "default": 5
+ }
+ }
+ },
+ "tests": [
+ {
+ "description": "an explicit property value is checked against maximum (passing)",
+ "data": { "alpha": 1 },
+ "valid": true
+ },
+ {
+ "description": "an explicit property value is checked against maximum (failing)",
+ "data": { "alpha": 5 },
+ "valid": false
+ },
+ {
+ "description": "missing properties are not filled in with the default",
+ "data": {},
+ "valid": true
+ }
+ ]
+ }
+]
diff --git a/internal/mcp/jsonschema/validate_test.go b/internal/mcp/jsonschema/validate_test.go
index 3d096df..d6be6f8 100644
--- a/internal/mcp/jsonschema/validate_test.go
+++ b/internal/mcp/jsonschema/validate_test.go
@@ -42,14 +42,12 @@
for _, file := range files {
base := filepath.Base(file)
t.Run(base, func(t *testing.T) {
- f, err := os.Open(file)
+ data, err := os.ReadFile(file)
if err != nil {
t.Fatal(err)
}
- defer f.Close()
- dec := json.NewDecoder(f)
var groups []testGroup
- if err := dec.Decode(&groups); err != nil {
+ if err := json.Unmarshal(data, &groups); err != nil {
t.Fatal(err)
}
for _, g := range groups {
