Port test-path-extname.

Author: goto-bus-stop

index.js

@@ -381,19 +381,22 @@ var posix = {
       }
       if (code === 46 /*.*/) {
           // If this is our first dot, mark it as the start of our extension
-          if (startDot === -1) startDot = i;else if (preDotState !== 1) preDotState = 1;
-        } else if (startDot !== -1) {
+          if (startDot === -1)
+            startDot = i;
+          else if (preDotState !== 1)
+            preDotState = 1;
+      } else if (startDot !== -1) {
         // We saw a non-dot and non-path separator before our dot, so we should
         // have a good chance at having a non-empty extension
         preDotState = -1;
       }
     }
 
     if (startDot === -1 || end === -1 ||
-    // We saw a non-dot character immediately before the dot
-    preDotState === 0 ||
-    // The (right-most) trimmed path component is exactly '..'
-    preDotState === 1 && startDot === end - 1 && startDot === startPart + 1) {
+        // We saw a non-dot character immediately before the dot
+        preDotState === 0 ||
+        // The (right-most) trimmed path component is exactly '..'
+        preDotState === 1 && startDot === end - 1 && startDot === startPart + 1) {
       return '';
     }
     return path.slice(startDot, end);

test/index.js

@@ -1,2 +1,3 @@
 require('./test-path-basename');
 require('./test-path-dirname');
+require('./test-path-extname');

test/test-path-extname.js

@@ -0,0 +1,96 @@
+'use strict';
+var tape = require('tape');
+var path = require('../');
+
+var slashRE = /\//g;
+
+var pairs = [
+  [__filename, '.js'],
+  ['', ''],
+  ['/path/to/file', ''],
+  ['/path/to/file.ext', '.ext'],
+  ['/path.to/file.ext', '.ext'],
+  ['/path.to/file', ''],
+  ['/path.to/.file', ''],
+  ['/path.to/.file.ext', '.ext'],
+  ['/path/to/f.ext', '.ext'],
+  ['/path/to/..ext', '.ext'],
+  ['/path/to/..', ''],
+  ['file', ''],
+  ['file.ext', '.ext'],
+  ['.file', ''],
+  ['.file.ext', '.ext'],
+  ['/file', ''],
+  ['/file.ext', '.ext'],
+  ['/.file', ''],
+  ['/.file.ext', '.ext'],
+  ['.path/file.ext', '.ext'],
+  ['file.ext.ext', '.ext'],
+  ['file.', '.'],
+  ['.', ''],
+  ['./', ''],
+  ['.file.ext', '.ext'],
+  ['.file', ''],
+  ['.file.', '.'],
+  ['.file..', '.'],
+  ['..', ''],
+  ['../', ''],
+  ['..file.ext', '.ext'],
+  ['..file', '.file'],
+  ['..file.', '.'],
+  ['..file..', '.'],
+  ['...', '.'],
+  ['...ext', '.ext'],
+  ['....', '.'],
+  ['file.ext/', '.ext'],
+  ['file.ext//', '.ext'],
+  ['file/', ''],
+  ['file//', ''],
+  ['file./', '.'],
+  ['file.//', '.'] ];
+
+tape('path.posix.extname', function (t) {
+  pairs.forEach(function (p) {
+    var input = p[0];
+    var expected = p[1];
+    t.strictEqual(expected, path.posix.extname(input));
+  });
+  t.end();
+});
+
+tape('path.win32.extname', { skip: true }, function (t) {
+  pairs.forEach(function (p) {
+    var input = p[0].replace(slashRE, '\\');
+    var expected = p[1];
+    t.strictEqual(expected, path.win32.extname(input));
+    t.strictEqual(expected, path.win32.extname("C:" + input));
+  });
+  t.end();
+});
+
+tape('path.win32.extname backslash', { skip: true }, function (t) {
+  // On Windows, backslash is a path separator.
+  t.strictEqual(path.win32.extname('.\\'), '');
+  t.strictEqual(path.win32.extname('..\\'), '');
+  t.strictEqual(path.win32.extname('file.ext\\'), '.ext');
+  t.strictEqual(path.win32.extname('file.ext\\\\'), '.ext');
+  t.strictEqual(path.win32.extname('file\\'), '');
+  t.strictEqual(path.win32.extname('file\\\\'), '');
+  t.strictEqual(path.win32.extname('file.\\'), '.');
+  t.strictEqual(path.win32.extname('file.\\\\'), '.');
+  t.end();
+});
+
+tape('path.posix.extname backslash', function (t) {
+  // On *nix, backslash is a valid name component like any other character.
+  t.strictEqual(path.posix.extname('.\\'), '');
+  t.strictEqual(path.posix.extname('..\\'), '.\\');
+  t.strictEqual(path.posix.extname('file.ext\\'), '.ext\\');
+  t.strictEqual(path.posix.extname('file.ext\\\\'), '.ext\\\\');
+  t.strictEqual(path.posix.extname('file\\'), '');
+  t.strictEqual(path.posix.extname('file\\\\'), '');
+  t.strictEqual(path.posix.extname('file.\\'), '.\\');
+  t.strictEqual(path.posix.extname('file.\\\\'), '.\\\\');
+  t.end();
+});
+