feat: include detailed error on jsonld diff

doc/ld/validator/testdata/extended_model.json

@@ -0,0 +1,21 @@
+{
+  "@context": [
+    "https://www.w3.org/2018/credentials/v1",
+    "%s"
+  ],
+  "id": "http://example.com/credentials/4643",
+  "type": [
+    "VerifiableCredential",
+    "CustomExt12"
+  ],
+  "issuer": "https://example.com/issuers/14",
+  "issuanceDate": "2018-02-24T05:28:04Z",
+  "referenceNumber": 83294847,
+  "credentialSubject": [
+    {
+      "id": "did:example:abcdef1234567",
+      "name": "Jane Doe",
+      "favoriteFood": "Papaya"
+    }
+  ]
+}

doc/ld/validator/types.go

@@ -0,0 +1,12 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package validator
+
+// Diff represents the difference between two objects.
+type Diff struct {
+	OriginalValue  interface{}
+	CompactedValue interface{}
+}

doc/ld/validator/validate.go

@@ -6,6 +6,7 @@ SPDX-License-Identifier: Apache-2.0
 package validator
 
 import (
+	json2 "encoding/json"
 	"errors"
 	"fmt"
 	"reflect"
@@ -18,10 +19,11 @@ import (
 )
 
 type validateOpts struct {
-	strict               bool
-	jsonldDocumentLoader ld.DocumentLoader
-	externalContext      []string
-	contextURIPositions  []string
+	strict                                    bool
+	jsonldDocumentLoader                      ld.DocumentLoader
+	externalContext                           []string
+	contextURIPositions                       []string
+	jsonldIncludeDetailedStructureDiffOnError bool
 }
 
 // ValidateOpts sets jsonld validation options.
@@ -34,6 +36,13 @@ func WithDocumentLoader(jsonldDocumentLoader ld.DocumentLoader) ValidateOpts {
 	}
 }
 
+// WithJSONLDIncludeDetailedStructureDiffOnError option is for including detailed structure diff in error message.
+func WithJSONLDIncludeDetailedStructureDiffOnError() ValidateOpts {
+	return func(opts *validateOpts) {
+		opts.jsonldIncludeDetailedStructureDiffOnError = true
+	}
+}
+
 // WithExternalContext option is for definition of external context when doing JSON-LD operations.
 func WithExternalContext(externalContext []string) ValidateOpts {
 	return func(opts *validateOpts) {
@@ -92,8 +101,17 @@ func ValidateJSONLDMap(docMap map[string]interface{}, options ...ValidateOpts) e
 		return fmt.Errorf("compact JSON-LD document: %w", err)
 	}
 
-	if opts.strict && !mapsHaveSameStructure(docMap, docCompactedMap) {
-		return errors.New("JSON-LD doc has different structure after compaction")
+	mapDiff := findMapDiff(docMap, docCompactedMap)
+	if opts.strict && len(mapDiff) != 0 {
+		errText := "JSON-LD doc has different structure after compaction"
+
+		if opts.jsonldIncludeDetailedStructureDiffOnError {
+			diff, _ := json2.Marshal(mapDiff) // nolint:errcheck
+
+			errText = fmt.Sprintf("%s. Details: %v", errText, string(diff))
+		}
+
+		return errors.New(errText)
 	}
 
 	err = validateContextURIPosition(opts.contextURIPositions, docMap)
@@ -136,40 +154,76 @@ func validateContextURIPosition(contextURIPositions []string, docMap map[string]
 	return nil
 }
 
-func mapsHaveSameStructure(originalMap, compactedMap map[string]interface{}) bool {
+// nolint:gocyclo,funlen
+func mapsHaveSameStructure(
+	originalMap,
+	compactedMap map[string]interface{},
+	path string,
+) map[string][]*Diff {
 	original := compactMap(originalMap)
 	compacted := compactMap(compactedMap)
 
 	if reflect.DeepEqual(original, compacted) {
-		return true
+		return nil
 	}
 
+	diffs := make(map[string][]*Diff)
+
 	if len(original) != len(compacted) {
-		return false
+		for k, v := range original {
+			diffKey := path + "." + k
+			if _, ok := compacted[k]; !ok {
+				diffs[diffKey] = append(diffs[diffKey], &Diff{OriginalValue: v, CompactedValue: "!missing!"})
+			}
+		}
+
+		for k, v := range compacted {
+			diffKey := path + "." + k
+
+			if _, ok := original[k]; !ok {
+				diffs[diffKey] = append(diffs[diffKey], &Diff{OriginalValue: "!missing!", CompactedValue: v})
+			}
+		}
+
+		return diffs
 	}
 
 	for k, v1 := range original {
+		diffKey := path + "." + k
+
 		v1Map, isMap := v1.(map[string]interface{})
 		if !isMap {
 			continue
 		}
 
 		v2, present := compacted[k]
 		if !present { // special case - the name of the map was mapped, cannot guess what's a new name
-			continue
+			continue // should not be counted as diff
 		}
 
 		v2Map, isMap := v2.(map[string]interface{})
 		if !isMap {
-			return false
+			diffs[diffKey] = append(diffs[diffKey], &Diff{OriginalValue: v1, CompactedValue: v2})
+		}
+
+		if v2Map == nil {
+			v2Map = make(map[string]interface{})
 		}
 
-		if !mapsHaveSameStructure(v1Map, v2Map) {
-			return false
+		mp := mapsHaveSameStructure(v1Map, v2Map, diffKey)
+		for m1, m2 := range mp {
+			diffs[m1] = append(diffs[m1], m2...)
 		}
 	}
 
-	return true
+	return diffs
+}
+
+func findMapDiff(originalMap, compactedMap map[string]interface{}) map[string][]*Diff {
+	originalMap = compactMap(originalMap)
+	compactedMap = compactMap(compactedMap)
+
+	return mapsHaveSameStructure(originalMap, compactedMap, "$")
 }
 
 func compactMap(m map[string]interface{}) map[string]interface{} {

doc/ld/validator/validate_test.go

@@ -30,6 +30,9 @@ var (
 
 	//go:embed testdata/context/wallet_v1.jsonld
 	walletV1Context []byte
+
+	//go:embed testdata/extended_model.json
+	extendedModel string
 )
 
 func Test_ValidateJSONLD(t *testing.T) {
@@ -187,29 +190,7 @@ func Test_ValidateJSONLDWithExtraUndefinedSubjectFields(t *testing.T) {
 	t.Run("Extended basic VC model, credentialSubject is defined as object - undefined fields present",
 		func(t *testing.T) {
 			// Use a different VC to verify the case when credentialSubject is an array.
-			vcJSONTemplate := `
-{
-  "@context": [
-    "https://www.w3.org/2018/credentials/v1",
-    "%s"
-  ],
-  "id": "http://example.com/credentials/4643",
-  "type": [
-    "VerifiableCredential",
-    "CustomExt12"
-  ],
-  "issuer": "https://example.com/issuers/14",
-  "issuanceDate": "2018-02-24T05:28:04Z",
-  "referenceNumber": 83294847,
-  "credentialSubject": [
-    {
-      "id": "did:example:abcdef1234567",
-      "name": "Jane Doe",
-      "favoriteFood": "Papaya"
-    }
-  ]
-}
-`
+			vcJSONTemplate := extendedModel
 
 			vcJSON := fmt.Sprintf(vcJSONTemplate, contextURL)
 
@@ -218,31 +199,21 @@ func Test_ValidateJSONLDWithExtraUndefinedSubjectFields(t *testing.T) {
 			require.EqualError(t, err, "JSON-LD doc has different structure after compaction")
 		})
 
+	t.Run("Extended basic VC model, credentialSubject is defined as object - undefined fields present and details",
+		func(t *testing.T) {
+			// Use a different VC to verify the case when credentialSubject is an array.
+			vcJSONTemplate := extendedModel
+
+			vcJSON := fmt.Sprintf(vcJSONTemplate, contextURL)
+
+			err := ValidateJSONLD(vcJSON, WithDocumentLoader(loader), WithJSONLDIncludeDetailedStructureDiffOnError())
+			require.Error(t, err)
+			require.EqualError(t, err, "JSON-LD doc has different structure after compaction. Details: {\"$.credentialSubject\":[{\"OriginalValue\":{\"favoriteFood\":\"Papaya\",\"id\":\"did:example:abcdef1234567\",\"name\":\"Jane Doe\"},\"CompactedValue\":\"did:example:abcdef1234567\"}],\"$.credentialSubject.favoriteFood\":[{\"OriginalValue\":\"Papaya\",\"CompactedValue\":\"!missing!\"}],\"$.credentialSubject.id\":[{\"OriginalValue\":\"did:example:abcdef1234567\",\"CompactedValue\":\"!missing!\"}],\"$.credentialSubject.name\":[{\"OriginalValue\":\"Jane Doe\",\"CompactedValue\":\"!missing!\"}]}") //nolint:lll
+		})
+
 	t.Run("Extended basic VC model, credentialSubject is defined as array - undefined fields present", func(t *testing.T) {
 		// Use a different VC to verify the case when credentialSubject is an array.
-		vcJSONTemplate := `
-{
-  "@context": [
-    "https://www.w3.org/2018/credentials/v1",
-    "%s"
-  ],
-  "id": "http://example.com/credentials/4643",
-  "type": [
-    "VerifiableCredential",
-    "CustomExt12"
-  ],
-  "issuer": "https://example.com/issuers/14",
-  "issuanceDate": "2018-02-24T05:28:04Z",
-  "referenceNumber": 83294847,
-  "credentialSubject": [
-    {
-      "id": "did:example:abcdef1234567",
-      "name": "Jane Doe",
-      "favoriteFood": "Papaya"
-    }
-  ]
-}
-`
+		vcJSONTemplate := extendedModel
 
 		vcJSON := fmt.Sprintf(vcJSONTemplate, contextURL)
 
@@ -591,6 +562,43 @@ func Benchmark_ValidateJSONLD(b *testing.B) {
 	})
 }
 
+func TestDiffOnEduCred(t *testing.T) {
+	diff := findMapDiff(map[string]any{
+		"degree": map[string]any{
+			"type": "BachelorDegree",
+			"name": "Bachelor of Science and Arts",
+		},
+		"alumniOf": map[string]any{
+			"id": "some-id",
+			"name": []any{
+				map[string]any{
+					"value": "University",
+					"lang":  "en",
+				},
+			},
+		},
+		"type": []interface{}{
+			"VerifiableCredential",
+			"UniversityDegreeCredential",
+		},
+	}, map[string]any{
+		"degree": map[string]any{
+			"type": "BachelorDegree",
+			"name": "Bachelor of Science and Arts",
+		},
+		"schema:alumniOf": map[string]any{
+			"id":          "some-id",
+			"schema:name": []any{},
+		},
+		"type": []interface{}{
+			"VerifiableCredential",
+			"UniversityDegreeCredential",
+		},
+	})
+
+	require.Len(t, diff, 0)
+}
+
 func createTestDocumentLoader(t *testing.T, extraContexts ...ldcontext.Document) *ldloader.DocumentLoader {
 	t.Helper()