path: refactor for performance and consistency

Improve performance by:
+ Not leaking the `arguments` object!
+ Getting the last character of a string by index, instead of
  with `.substr()` or `.slice()`

Improve code consistency by:
+ Using `[]` instead of `.charAt()` where possible
+ Using a function declaration instead of a var declaration
+ Using `.slice()` with clearer arguments
+ Checking if `dir` is truthy in `win32.format`
  (added tests for this)

Improve both by:
+ Making the reusable `trimArray()` function
+ Standardizing getting certain path statistics with
  the new `win32StatPath()` function

PR-URL: https://github.com/nodejs/io.js/pull/1778
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>

1 files changed, 22 insertions, 4 deletions

diff --git a/test/parallel/test-path-parse-format.js b/test/parallel/test-path-parse-format.js
index 37f37fc9b5..677bf3241f 100644
--- a/test/parallel/test-path-parse-format.js
+++ b/test/parallel/test-path-parse-format.js
@@ -15,7 +15,12 @@ var winPaths = [
   '\\\\server two\\shared folder\\file path.zip',
   '\\\\teela\\admin$\\system32',
   '\\\\?\\UNC\\server\\share'
+];
 
+var winSpecialCaseFormatTests = [
+  [{dir: 'some\\dir'}, 'some\\dir\\'],
+  [{base: 'index.html'}, 'index.html'],
+  [{}, '']
 ];
 
 var unixPaths = [
@@ -30,6 +35,12 @@ var unixPaths = [
   'C:\\foo'
 ];
 
+var unixSpecialCaseFormatTests = [
+  [{dir: 'some/dir'}, 'some/dir/'],
+  [{base: 'index.html'}, 'index.html'],
+  [{}, '']
+];
+
 var errors = [
   {method: 'parse', input: [null],
    message: /Path must be a string. Received null/},
@@ -57,10 +68,12 @@ var errors = [
    message: /'pathObject.root' must be a string or undefined, not number/},
 ];
 
-check(path.win32, winPaths);
-check(path.posix, unixPaths);
+checkParseFormat(path.win32, winPaths);
+checkParseFormat(path.posix, unixPaths);
 checkErrors(path.win32);
 checkErrors(path.posix);
+checkFormat(path.win32, winSpecialCaseFormatTests);
+checkFormat(path.posix, unixSpecialCaseFormatTests);
 
 function checkErrors(path) {
   errors.forEach(function(errorCase) {
@@ -79,8 +92,7 @@ function checkErrors(path) {
   });
 }
 
-
-function check(path, paths) {
+function checkParseFormat(path, paths) {
   paths.forEach(function(element, index, array) {
     var output = path.parse(element);
     assert.strictEqual(path.format(output), element);
@@ -89,3 +101,9 @@ function check(path, paths) {
     assert.strictEqual(output.ext, path.extname(element));
   });
 }
+
+function checkFormat(path, testCases) {
+  testCases.forEach(function(testCase) {
+    assert.strictEqual(path.format(testCase[0]), testCase[1]);
+  });
+}