Add support of multi oidcIssuer relations per one user's profile

src/oidc-manager.js

@@ -379,7 +379,7 @@ class OidcManager {
     }
 
     // Otherwise, verify that issuer is the preferred OIDC provider for the web id
-    return discoverProviderFor(webId)
+    return discoverProviderFor(webId, issuer)
       .then(preferredProvider => {
         if (preferredProvider === issuer) { // everything checks out
           return webId

src/preferred-provider.js

@@ -61,20 +61,48 @@ function providerExists (uri) {
  *  given Web ID, extracted from Link rel header or profile body. If no
  *  provider URI was found, reject with an error.
  */
-function discoverProviderFor (webId) {
+function discoverProviderFor (webId, issuer) {
   return discoverFromHeaders(webId)
 
-    .then(providerFromHeaders => providerFromHeaders || discoverFromProfile(webId))
+    .then(providerFromHeaders => providerFromHeaders || discoverAllFromProfile(webId))
 
     .then(providerUri => {
-      // drop the path (provider origin only)
-      if (providerUri) {
-        providerUri = (new URL(providerUri)).origin
+      if (Array.isArray(providerUri)) {
+        let list = providerUri
+        let lastErr = null
+
+        for (let i = 0; i < list.length; i++) {
+          lastErr = null
+          providerUri = list[i]
+          if (providerUri) {
+            providerUri = (new URL(providerUri)).origin
+          }
+
+          try {
+            validateProviderUri(providerUri, webId) // Throw an error if empty or invalid
+          } catch (err) {
+            lastErr = err
+          }
+
+          if (lastErr === null && ((issuer && providerUri === issuer) || !issuer)) {
+            return providerUri
+          }
+        }
+        if (lastErr) {
+          throw lastErr
+        } else {
+          validateProviderUri(null, webId) // Throw an error if empty or invalid
+        }
+      } else {
+        // drop the path (provider origin only)
+        if (providerUri) {
+          providerUri = (new URL(providerUri)).origin
+        }
+
+        validateProviderUri(providerUri, webId) // Throw an error if empty or invalid
+
+        return providerUri
       }
-
-      validateProviderUri(providerUri, webId) // Throw an error if empty or invalid
-
-      return providerUri
     })
 }
 
@@ -94,16 +122,30 @@ function discoverFromHeaders (webId) {
     })
 }
 
-function discoverFromProfile (webId) {
+function discoverAllFromProfile (webId) {
   const store = rdf.graph()
 
   const fetcher = rdf.fetcher(store)
 
   return fetcher.load(webId, { force: true })
     .then(response => {
+      if (!response.ok) {
+        let error = new Error(`Could not reach Web ID ${webId} to discover provider`)
+        error.statusCode = 400
+        throw error
+      }
+
       let providerTerm = rdf.namedNode('http://www.w3.org/ns/solid/terms#oidcIssuer')
-      let providerUri = store.anyValue(rdf.namedNode(webId), providerTerm)
-      return providerUri
+      let idp = store.each(rdf.namedNode(webId), providerTerm, undefined)
+      let list = []
+
+      for (let i = 0; i < idp.length; i++) {
+        if (idp[i].uri) {
+          list.push(idp[i].uri)
+        }
+      }
+
+      return list
     }, err => {
       let error = new Error(`Could not reach Web ID ${webId} to discover provider`)
       error.cause = err

test/resources/sample-webid-profile1.js

@@ -0,0 +1,20 @@
+module.exports = `
+@prefix solid: <http://www.w3.org/ns/solid/terms#>.
+@prefix foaf: <http://xmlns.com/foaf/0.1/>.
+@prefix pim: <http://www.w3.org/ns/pim/space#>.
+@prefix schema: <http://schema.org/>.
+@prefix ldp: <http://www.w3.org/ns/ldp#>.
+
+<>
+    a foaf:PersonalProfileDocument ;
+    foaf:primaryTopic <#me> .
+
+<#me>
+    a schema:Person ;
+
+    solid:account </> ;  # link to the account uri
+    pim:storage </> ;    # root storage
+
+    solid:oidcIssuer <https://provider2.com> ;
+    solid:oidcIssuer <https://provider.com> .
+`

test/unit/preferred-provider-test.js

@@ -64,6 +64,23 @@ describe('preferred-provider.js', () => {
         })
     })
 
+    it('should extract and validate the provider uri from the webid profile with multi oidcIssuer', () => {
+      nock(serverUri)
+        .options('/')
+        .reply(204, 'No content')
+
+      nock(serverUri)
+        .get('/')
+        .reply(200, sampleProfileSrc, {
+          'Content-Type': 'text/turtle'
+        })
+
+      return provider.discoverProviderFor(webId, 'https://provider.com')
+        .then(providerUri => {
+          expect(providerUri).to.equal('https://provider.com')
+        })
+    })
+
     it('should throw an error if webid is reachable but no provider uri found', done => {
       nock(serverUri)
         .options('/')