add two possible solutions

json/parser_test.go

@@ -3,11 +3,13 @@ package json
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"os"
 	"strings"
 	"testing"
 
 	core "github.com/iden3/go-iden3-core/v2"
+	"github.com/iden3/go-merkletree-sql/v2"
 	"github.com/iden3/go-schema-processor/v2/merklize"
 	"github.com/iden3/go-schema-processor/v2/processor"
 	tst "github.com/iden3/go-schema-processor/v2/testing"
@@ -17,6 +19,7 @@ import (
 )
 
 func TestParser_parseSlots(t *testing.T) {
+	fmt.Println(merkletree.HashZero.Hex())
 	defer tst.MockHTTPClient(t,
 		map[string]string{
 			"https://www.w3.org/2018/credentials/v1":              "../merklize/testdata/httpresp/credentials-v1.jsonld",

loaders/constants.go

@@ -0,0 +1,247 @@
+package loaders
+
+// W3CCredential2018ContextURL is w3c context url
+//
+//nolint:golint,gosec
+const W3CCredential2018ContextURL = "https://www.w3.org/2018/credentials/v1"
+
+// W3CCredential2018ContextDocument is w3c context file
+//
+//nolint:golint,gosec
+const W3CCredential2018ContextDocument string = `{
+  "@context": {
+    "@version": 1.1,
+    "@protected": true,
+
+    "id": "@id",
+    "type": "@type",
+
+    "VerifiableCredential": {
+      "@id": "https://www.w3.org/2018/credentials#VerifiableCredential",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "id": "@id",
+        "type": "@type",
+
+        "cred": "https://www.w3.org/2018/credentials#",
+        "sec": "https://w3id.org/security#",
+        "xsd": "http://www.w3.org/2001/XMLSchema#",
+
+        "credentialSchema": {
+          "@id": "cred:credentialSchema",
+          "@type": "@id",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "cred": "https://www.w3.org/2018/credentials#",
+
+            "JsonSchemaValidator2018": "cred:JsonSchemaValidator2018"
+          }
+        },
+        "credentialStatus": {"@id": "cred:credentialStatus", "@type": "@id"},
+        "credentialSubject": {"@id": "cred:credentialSubject", "@type": "@id"},
+        "evidence": {"@id": "cred:evidence", "@type": "@id"},
+        "expirationDate": {"@id": "cred:expirationDate", "@type": "xsd:dateTime"},
+        "holder": {"@id": "cred:holder", "@type": "@id"},
+        "issued": {"@id": "cred:issued", "@type": "xsd:dateTime"},
+        "issuer": {"@id": "cred:issuer", "@type": "@id"},
+        "issuanceDate": {"@id": "cred:issuanceDate", "@type": "xsd:dateTime"},
+        "proof": {"@id": "sec:proof", "@type": "@id", "@container": "@graph"},
+        "refreshService": {
+          "@id": "cred:refreshService",
+          "@type": "@id",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "cred": "https://www.w3.org/2018/credentials#",
+
+            "ManualRefreshService2018": "cred:ManualRefreshService2018"
+          }
+        },
+        "termsOfUse": {"@id": "cred:termsOfUse", "@type": "@id"},
+        "validFrom": {"@id": "cred:validFrom", "@type": "xsd:dateTime"},
+        "validUntil": {"@id": "cred:validUntil", "@type": "xsd:dateTime"}
+      }
+    },
+
+    "VerifiablePresentation": {
+      "@id": "https://www.w3.org/2018/credentials#VerifiablePresentation",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "id": "@id",
+        "type": "@type",
+
+        "cred": "https://www.w3.org/2018/credentials#",
+        "sec": "https://w3id.org/security#",
+
+        "holder": {"@id": "cred:holder", "@type": "@id"},
+        "proof": {"@id": "sec:proof", "@type": "@id", "@container": "@graph"},
+        "verifiableCredential": {"@id": "cred:verifiableCredential", "@type": "@id", "@container": "@graph"}
+      }
+    },
+
+    "EcdsaSecp256k1Signature2019": {
+      "@id": "https://w3id.org/security#EcdsaSecp256k1Signature2019",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "id": "@id",
+        "type": "@type",
+
+        "sec": "https://w3id.org/security#",
+        "xsd": "http://www.w3.org/2001/XMLSchema#",
+
+        "challenge": "sec:challenge",
+        "created": {"@id": "http://purl.org/dc/terms/created", "@type": "xsd:dateTime"},
+        "domain": "sec:domain",
+        "expires": {"@id": "sec:expiration", "@type": "xsd:dateTime"},
+        "jws": "sec:jws",
+        "nonce": "sec:nonce",
+        "proofPurpose": {
+          "@id": "sec:proofPurpose",
+          "@type": "@vocab",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "sec": "https://w3id.org/security#",
+
+            "assertionMethod": {"@id": "sec:assertionMethod", "@type": "@id", "@container": "@set"},
+            "authentication": {"@id": "sec:authenticationMethod", "@type": "@id", "@container": "@set"}
+          }
+        },
+        "proofValue": "sec:proofValue",
+        "verificationMethod": {"@id": "sec:verificationMethod", "@type": "@id"}
+      }
+    },
+
+    "EcdsaSecp256r1Signature2019": {
+      "@id": "https://w3id.org/security#EcdsaSecp256r1Signature2019",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "id": "@id",
+        "type": "@type",
+
+        "sec": "https://w3id.org/security#",
+        "xsd": "http://www.w3.org/2001/XMLSchema#",
+
+        "challenge": "sec:challenge",
+        "created": {"@id": "http://purl.org/dc/terms/created", "@type": "xsd:dateTime"},
+        "domain": "sec:domain",
+        "expires": {"@id": "sec:expiration", "@type": "xsd:dateTime"},
+        "jws": "sec:jws",
+        "nonce": "sec:nonce",
+        "proofPurpose": {
+          "@id": "sec:proofPurpose",
+          "@type": "@vocab",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "sec": "https://w3id.org/security#",
+
+            "assertionMethod": {"@id": "sec:assertionMethod", "@type": "@id", "@container": "@set"},
+            "authentication": {"@id": "sec:authenticationMethod", "@type": "@id", "@container": "@set"}
+          }
+        },
+        "proofValue": "sec:proofValue",
+        "verificationMethod": {"@id": "sec:verificationMethod", "@type": "@id"}
+      }
+    },
+
+    "Ed25519Signature2018": {
+      "@id": "https://w3id.org/security#Ed25519Signature2018",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "id": "@id",
+        "type": "@type",
+
+        "sec": "https://w3id.org/security#",
+        "xsd": "http://www.w3.org/2001/XMLSchema#",
+
+        "challenge": "sec:challenge",
+        "created": {"@id": "http://purl.org/dc/terms/created", "@type": "xsd:dateTime"},
+        "domain": "sec:domain",
+        "expires": {"@id": "sec:expiration", "@type": "xsd:dateTime"},
+        "jws": "sec:jws",
+        "nonce": "sec:nonce",
+        "proofPurpose": {
+          "@id": "sec:proofPurpose",
+          "@type": "@vocab",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "sec": "https://w3id.org/security#",
+
+            "assertionMethod": {"@id": "sec:assertionMethod", "@type": "@id", "@container": "@set"},
+            "authentication": {"@id": "sec:authenticationMethod", "@type": "@id", "@container": "@set"}
+          }
+        },
+        "proofValue": "sec:proofValue",
+        "verificationMethod": {"@id": "sec:verificationMethod", "@type": "@id"}
+      }
+    },
+
+    "RsaSignature2018": {
+      "@id": "https://w3id.org/security#RsaSignature2018",
+      "@context": {
+        "@version": 1.1,
+        "@protected": true,
+
+        "challenge": "sec:challenge",
+        "created": {"@id": "http://purl.org/dc/terms/created", "@type": "xsd:dateTime"},
+        "domain": "sec:domain",
+        "expires": {"@id": "sec:expiration", "@type": "xsd:dateTime"},
+        "jws": "sec:jws",
+        "nonce": "sec:nonce",
+        "proofPurpose": {
+          "@id": "sec:proofPurpose",
+          "@type": "@vocab",
+          "@context": {
+            "@version": 1.1,
+            "@protected": true,
+
+            "id": "@id",
+            "type": "@type",
+
+            "sec": "https://w3id.org/security#",
+
+            "assertionMethod": {"@id": "sec:assertionMethod", "@type": "@id", "@container": "@set"},
+            "authentication": {"@id": "sec:authenticationMethod", "@type": "@id", "@container": "@set"}
+          }
+        },
+        "proofValue": "sec:proofValue",
+        "verificationMethod": {"@id": "sec:verificationMethod", "@type": "@id"}
+      }
+    },
+
+    "proof": {"@id": "https://w3id.org/security#proof", "@type": "@id", "@container": "@graph"}
+  }
+}`

loaders/document_loader.go

@@ -13,6 +13,8 @@ type documentLoader struct {
 	httpLoader *ld.RFC7324CachingDocumentLoader
 	ipfsCli    *shell.Shell
 	ipfsGW     string
+
+	localCacheFn func(url string) (io.Reader, error)
 }
 
 // NewDocumentLoader creates a new document loader with a cache for http.
@@ -28,6 +30,25 @@ func NewDocumentLoader(ipfsCli *shell.Shell, ipfsGW string) ld.DocumentLoader {
 func (d *documentLoader) LoadDocument(
 	u string) (doc *ld.RemoteDocument, err error) {
 
+	if d.localCacheFn != nil {
+		var r io.Reader
+		r, err = d.localCacheFn(u)
+		if err != nil {
+			return nil, err
+		}
+		if r != nil {
+			var docFromReader interface{}
+			docFromReader, err = ld.DocumentFromReader(r)
+			if err == nil {
+				return nil, err
+			}
+			return &ld.RemoteDocument{
+				DocumentURL: u,
+				Document:    docFromReader,
+				ContextURL:  u,
+			}, nil
+		}
+	}
 	const ipfsPrefix = "ipfs://"
 
 	switch {
@@ -65,6 +86,11 @@ func (d *documentLoader) LoadDocument(
 	}
 }
 
+func (d *documentLoader) SetLocalReader(
+	f func(url string) (io.Reader, error)) {
+	d.localCacheFn = f
+}
+
 func (d *documentLoader) loadDocumentFromIPFSNode(
 	ipfsURL string) (document any, err error) {
 

loaders/w3c_loader.go

@@ -0,0 +1,41 @@
+package loaders
+
+import (
+	"net/http"
+	"strings"
+
+	shell "github.com/ipfs/go-ipfs-api"
+	"github.com/piprate/json-gold/ld"
+)
+
+type W3CDocumentLoader struct {
+	documentLoader
+}
+
+// NewW3CDocumentLoader creates a new document loader with a predefined http schema
+func NewW3CDocumentLoader(ipfsCli *shell.Shell, ipfsGW string, httpClient *http.Client) ld.DocumentLoader {
+	return &W3CDocumentLoader{
+		documentLoader: documentLoader{
+			httpLoader: ld.NewRFC7324CachingDocumentLoader(httpClient),
+			ipfsCli:    ipfsCli,
+			ipfsGW:     ipfsGW,
+		},
+	}
+}
+
+func (d *W3CDocumentLoader) LoadDocument(
+	u string) (doc *ld.RemoteDocument, err error) {
+
+	if u == W3CCredential2018ContextURL {
+		w3cDoc, errIn := ld.DocumentFromReader(strings.NewReader(W3CCredential2018ContextDocument))
+		if errIn != nil {
+			return nil, errIn
+		}
+		return &ld.RemoteDocument{
+			DocumentURL: u,
+			Document:    w3cDoc,
+			ContextURL:  u,
+		}, nil
+	}
+	return d.LoadDocument(u)
+}

loaders/w3c_loader_test.go

@@ -0,0 +1,33 @@
+package loaders_test
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/iden3/go-schema-processor/v2/loaders"
+	"github.com/stretchr/testify/require"
+)
+
+func TestW3CLoader_JSONUnmarshal(t *testing.T) {
+
+	w3cLoader := loaders.NewW3CDocumentLoader(nil, "https://ipfs.io", createDisabledHTTPClient())
+	doc, err := w3cLoader.LoadDocument(loaders.W3CCredential2018ContextURL)
+	require.NoError(t, err)
+
+	require.NotNil(t, (doc.Document.(map[string]interface{}))["@context"])
+}
+
+type DisableHTTPTransport struct{}
+
+func (t *DisableHTTPTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	// Do nothing and return a dummy response
+	return &http.Response{
+		StatusCode: http.StatusNotImplemented, // You can choose any status code
+		Body:       nil,
+	}, nil
+}
+func createDisabledHTTPClient() *http.Client {
+	return &http.Client{
+		Transport: &DisableHTTPTransport{},
+	}
+}