Expand the JSON reporter to enable a progress bar.

json_reporter.schema.json

 {
   "$schema": "http://json-schema.org/draft-04/schema#",
   "description": "An event emitted by the test package's JSON reporter",
 
   "definitions": {
     "Test": {
       "required": ["id", "name", "suiteID", "groupIDs", "metadata"],
       "properties": {
         "id": {"type": "integer", "minimum": 0},
         "name": {"type": "string"},
@@ skipping 21 matching lines @@
       "required": ["id", "name", "suiteID"],
       "properties": {
         "id": {"type": "integer", "minimum": 0},
         "suiteID": {"type": "integer", "minimum": 0},
         "parentID": {
           "oneOf": [{"type": "integer", "minimum": 0}, {"type": "null"}]
         },
         "name": {
           "oneOf": [{"type": "string"}, {"type": "null"}]
         },
-        "metadata": {"$ref": "#/definitions/Metadata"}
+        "metadata": {"$ref": "#/definitions/Metadata"},
+        "testCount": {"type": "integer", "minimum": 0}
       }
     },
 
     "Metadata": {
       "required": ["skip", "skipReason"],
       "properties": {
         "skip": {"type": "boolean"},
         "skipReason": {
           "oneOf": [{"type": "string"}, {"type": "null"}]
         }
@@ skipping 23 matching lines @@
     {
       "title": "TestStartEvent",
       "required": ["test"],
       "properties": {
         "type": {"enum": ["testStart"]},
         "test": {"$ref": "#/definitions/Test"}
       }
     },
 
     {
+      "title": "AllSuitesEvent",
+      "required": ["count"],
+      "properties": {
+        "type": {"enum": ["allSuites"]},
+        "count": {"type": "integer", "minimum": 0}
+      }
+    },
+
+    {
       "title": "SuiteEvent",
       "required": ["suite"],
       "properties": {
         "type": {"enum": ["suite"]},
         "group": {"$ref": "#/definitions/Suite"}
       }
     },
 
     {
       "title": "GroupEvent",
@@ skipping 47 matching lines @@
     },
 
     {
       "title": "FutureEvent",
       "description":
         "A placeholder event to allow new events to be added in the future.",
       "properties": {
         "type": {
           "not": {
             "enum": [
-              "start", "testStart", "suite", "group", "print", "error",
-              "testDone", "done"
+              "start", "testStart", "allSuites", "suite", "group", "print",
+              "error", "testDone", "done"
             ]
           }
         }
       }
     }
   ]
 }