Fix retrieving metrics for a subject (#1)

* Fix retrieving metrics for a subject

src/metrics/index.js

@@ -2,23 +2,58 @@
 
 const check = require('check-types');
 const common = require('./../common');
+const pageToGenerator = require('../utils/pageToGenerator');
 const ENDPT = 'metrics';
 
 // Metrics module
 // @param context: The context to make requests in. Basically, `this`
 module.exports = function metrics(context) {
     const obj = common(context, ENDPT);
 
-    // retrives metrics for a subject
+    // retrives metrics for a subject, returned as an array
     // @param subject: subject to retrieve the metrics for
     // @param userOpts: option overrides for this request
     // @returns Returns a promise that resolves to a list of metrics
-    function getSubjectMetrics(subject, userOpts) {
+    function getSubjectMetricsList(subject, userOpts) {
         check.string(subject, 'subject must be a string');
 
-        return context.http.makeRequest({
-            url: `/v1/apps/${context.applicationId}/${ENDPT}/${subject}`
-        }, userOpts).then(function(body) { return body.data; });
+        let array = [];
+        let url = `/v1/apps/${context.applicationId}/${ENDPT}/${subject}`;
+
+        function pageFn() {
+            return context.http.makeRequest({ url }, userOpts).then(function(body) {
+                array = array.concat(body.data || []); // concatinate the new data
+
+                url = body.pages.next;
+                if (url) {
+                    return pageFn();
+                } else {
+                    return array;
+                }
+            });
+        }
+
+        return pageFn();
+    }
+
+    // retrives metrics for a subject, returned as an iterator
+    // @param subject: subject to retrieve the metrics for
+    // @param userOpts: option overrides for this request
+    // @return An iterator that returns promises that resolve with the next object
+    function* getAllSubjectMetrics(subject, userOpts) {
+        check.string(subject, 'subject must be a string');
+
+        function pageFn() {
+            let url = `/v1/apps/${context.applicationId}/${ENDPT}/${subject}`;
+            return function() {
+                return context.http.makeRequest({ url }, userOpts).then(function(body) {
+                    url = body.pages.next;
+                    return body;
+                });
+            };
+        }
+
+        yield* pageToGenerator(pageFn());
     }
 
     // retrieves a single metric for a subject by key
@@ -54,7 +89,8 @@ module.exports = function metrics(context) {
         getAll: obj.getAll,
         getList: obj.getList,
         create: obj.create,
-        getSubjectMetrics,
+        getSubjectMetricsList,
+        getAllSubjectMetrics,
         getIndividualSubjectMetric, // TODO: consider aliasing to "get"
         removeIndividualSubjectMetric // TODO: consider aliasing to "remove"
     };