feat(debug): implement debug utility

package.json

@@ -92,6 +92,7 @@
     "@commitlint/config-angular": "^7.0.1",
     "@types/chai": "^4.1.5",
     "@types/chai-subset": "^1.3.1",
+    "@types/debug": "0.0.30",
     "@types/mocha": "^5.2.5",
     "@types/node": "^8.0.58",
     "@types/sinon": "^5.0.2",
@@ -130,6 +131,7 @@
     "@types/node": ">= 8.0.58"
   },
   "dependencies": {
+    "debug": "^4.0.1",
     "follow-redirects": "^1.5.8",
     "getroot": "^1.0.0",
     "is-buffer": "^2.0.3",

src/utils/debug.ts

@@ -0,0 +1,5 @@
+import * as debug from 'debug';
+
+const getDebug = (identifier: string) => debug(`oxid:${identifier}`);
+
+export { getDebug };

src/utils/parseJsonResponse.ts

@@ -1,4 +1,7 @@
 import { XSSI_PREFIX } from './base';
+import { getDebug } from './debug';
+
+const debug = getDebug('parseJsonResponse');
 
 /**
  * Parse given body as json object if responseType is configured
@@ -9,6 +12,7 @@ const parseJsonResponse = (status: number, body: any) => {
   // but a successful status code can still result in an error if the user
   // asked for JSON data and the body cannot be parsed as such.
   const ok = status >= 200 && status < 300;
+  debug(`Status '${status}' considered as '${ok ? 'ok' : 'not ok'}'`);
 
   // Save the original body, before attempting XSSI prefix stripping.
   const originalBody = body;
@@ -31,6 +35,7 @@ const parseJsonResponse = (status: number, body: any) => {
       ret = { error, text: ret };
     }
 
+    debug(`parse response body failed, returning original body with error`, error);
     return { ok: false, body: ret };
   }
 };