fix: allow distributed claims to be missing from the response

fixes #197

lib/client.js

@@ -48,13 +48,14 @@ function cleanUpClaims(claims) {
   }
 }
 
-function assignClaim(target, source, sourceName) {
+function assignClaim(target, source, sourceName, throwOnMissing = true) {
   return ([claim, inSource]) => {
     if (inSource === sourceName) {
-      if (source[claim] === undefined) {
+      if (throwOnMissing && source[claim] === undefined) {
         throw new RPError(`expected claim "${claim}" in "${sourceName}"`);
+      } else if (source[claim] !== undefined) {
+        target[claim] = source[claim];
       }
-      target[claim] = source[claim];
       delete target._claim_names[claim];
     }
   };
@@ -1196,7 +1197,9 @@ module.exports = (issuer, aadIssValidation = false) => class Client extends Base
 
         const decoded = await claimJWT.call(this, body);
         delete claims._claim_sources[sourceName];
-        Object.entries(claims._claim_names).forEach(assignClaim(claims, decoded, sourceName));
+        Object.entries(claims._claim_names).forEach(
+          assignClaim(claims, decoded, sourceName, false),
+        );
       } catch (err) {
         err.src = sourceName;
         throw err;

test/client/client_instance.test.js

@@ -2442,7 +2442,7 @@ describe('Client', () => {
         });
       });
 
-      it('validates claims that should be present are', function () {
+      it('allows claims to be omitted', function () {
         return getJWT({
           // credit_history: 'foobar',
         }, 'src1').then((jwt) => {
@@ -2460,9 +2460,9 @@ describe('Client', () => {
           };
 
           return this.client.fetchDistributedClaims(userinfo)
-            .then(fail, function (error) {
-              expect(error).to.have.property('src', 'src1');
-              expect(error.message).to.equal('expected claim "credit_history" in "src1"');
+            .then((result) => {
+              expect(result).to.eql({ sub: 'userID' });
+              expect(result).to.equal(userinfo);
             });
         });
       });