refactored internals to use Result instead of tuple

Author: Raynos

index.js

@@ -1,5 +1,6 @@
 var process = require('process');
 var EventEmitter = require('events').EventEmitter;
+var Result = require('raynos-rust-result');
 
 var errors = require('./errors.js');
 var readDatacenter = require('./read-datacenter.js');
@@ -21,16 +22,17 @@ function fetchConfigSync(dirname, opts) {
     // config is EventEmitter purely for `.emit('error', err)`
     var config = new EventEmitter();
 
-    var datacenterTuple = readDatacenter(opts);
+    var result = readDatacenter(opts);
 
-    if (datacenterTuple[0]) {
+    if (Result.isErr(result)) {
+        var err = Result.Err(result);
         // throw error async. this allows for breaking a 
         // circular dependency between config & logger.
         process.nextTick(function () {
-            config.emit('error', datacenterTuple[0]);
+            config.emit('error', err);
         });
     } else {
-        opts.datacenterValue = datacenterTuple[1];
+        opts.datacenterValue = Result.Ok(result);
     }
 
     var configState = getConfigState(dirname, opts);

package.json

@@ -18,7 +18,8 @@
     "error": "^4.1.1",
     "flatten-prototypes": "^3.0.0",
     "minimist": "^1.1.0",
-    "process": "^0.7.0"
+    "process": "^0.7.0",
+    "raynos-rust-result": "0.1.0-improvement3"
   },
   "devDependencies": {
     "coveralls": "^2.10.0",

read-datacenter.js

@@ -1,4 +1,5 @@
 var fs = require('fs');
+var Result = require('raynos-rust-result');
 
 var errors = require('./errors.js');
 
@@ -14,40 +15,41 @@ function readDatacenter(opts) {
         });
     }
 
-    var result, error = null;
+    var result;
 
     // specifying a datacenter is optional in dev but required
     // in production.
     if (opts.dc) {
-        var tuple = readFileOrError(opts.dc);
-        if (tuple[0]) {
-            var err = tuple[0];
+        var fileResult = readFileOrError(opts.dc);
+        if (Result.isErr(fileResult)) {
+            var err = Result.Err(fileResult);
             // create error synchronously for correct stack trace
             if (NODE_ENV === 'production') {
-                error = errors.DatacenterFileRequired({
+                result = Result.Err(errors.DatacenterFileRequired({
                     path: err.path,
                     errno: err.errno,
                     code: err.code,
                     syscall: err.syscall
-                });
+                }));
             } else {
-                error = errors.MissingDatacenter({
+                result = Result.Err(errors.MissingDatacenter({
                     path: err.path,
                     errno: err.errno,
                     code: err.code,
                     syscall: err.syscall
-                });
+                }));
             }
         } else {
-            result = {
-                'datacenter': tuple[1].replace(/\s/g, '')
-            };
+            result = Result.Ok({
+                'datacenter': Result.Ok(fileResult)
+                    .replace(/\s/g, '')
+            });
         }
     } else {
-        result = null;
+        result = Result.Ok(null);
     }
 
-    return [error, result];
+    return result;
 }
 
 // break try catch into small function to avoid v8 de-optimization
@@ -56,8 +58,8 @@ function readFileOrError(uri) {
     try {
         content = fs.readFileSync(uri, 'utf8');
     } catch (err) {
-        return [err, null];
+        return Result.Err(err);
     }
 
-    return [null, content];
+    return Result.Ok(content);
 }