Handle case sensitive file systems with nocase option.

Uses detect-file
Returns actual filepath on case sensitive system when nocase is true

.travis.yml

@@ -1,7 +1,10 @@
 sudo: false
 language: node_js
+os:
+  - linux
+  - osx
 node_js:
-  - "stable"
+  - "6"
   - "5"
   - "4"
   - "0.12"

index.js

@@ -8,7 +8,7 @@ var fs = require('fs');
 var path = require('path');
 var isGlob = require('is-glob');
 var resolveDir = require('resolve-dir');
-var exists = require('fs-exists-sync');
+var detect = require('detect-file');
 var mm = require('micromatch');
 
 /**
@@ -46,13 +46,13 @@ function lookup(pattern, options) {
   if (isGlob(pattern)) {
     return matchFile(cwd, pattern, options);
   } else {
-    return findFile(cwd, pattern);
+    return findFile(cwd, pattern, options);
   }
 }
 
 function matchFile(cwd, pattern, opts) {
   var isMatch = mm.matcher(pattern, opts);
-  var files = fs.readdirSync(cwd);
+  var files = tryReaddirSync(cwd);
   var len = files.length;
   var idx = -1;
 
@@ -71,10 +71,11 @@ function matchFile(cwd, pattern, opts) {
   return matchFile(dir, pattern, opts);
 }
 
-function findFile(cwd, filename) {
+function findFile(cwd, filename, options) {
+  var res;
   var fp = cwd ? path.resolve(cwd, filename) : filename;
-  if (exists(fp)) {
-    return fp;
+  if (res = detect(fp, options)) {
+    return res;
   }
 
   var segs = cwd.split(path.sep);
@@ -83,9 +84,16 @@ function findFile(cwd, filename) {
   while (len--) {
     cwd = segs.slice(0, len).join(path.sep);
     fp = path.resolve(cwd, filename);
-    if (exists(fp)) {
-      return fp;
+    if (res = detect(fp, options)) {
+      return res;
     }
   }
   return null;
 }
+
+function tryReaddirSync(fp) {
+  try {
+    return fs.readdirSync(fp);
+  } catch(err) {}
+  return [];
+}

package.json

@@ -20,12 +20,13 @@
     "test": "grunt && mocha"
   },
   "dependencies": {
-    "fs-exists-sync": "^0.1.0",
+    "detect-file": "^0.1.0",
     "is-glob": "^2.0.1",
     "micromatch": "^2.3.7",
     "resolve-dir": "^0.1.0"
   },
   "devDependencies": {
+    "fs-exists-sync": "^0.1.0",
     "grunt": "^1.0.1",
     "grunt-contrib-jshint": "^0.12.0",
     "is-absolute": "^0.2.3",

test/fixtures/Mochafile.txt

@@ -0,0 +1 @@
+root

test/fixtures/a/Mochafile.txt

@@ -0,0 +1 @@
+a

test/fixtures/a/b/Mochafile.txt

@@ -0,0 +1 @@
+b

test/fixtures/a/b/c/Mochafile.txt

@@ -0,0 +1 @@
+c

test/fixtures/a/b/c/d/Mochafile.txt

@@ -0,0 +1 @@
+d

test/fixtures/a/b/c/d/e/Mochafile.txt

@@ -0,0 +1 @@
+e

test/fixtures/a/b/c/d/e/f/Mochafile.txt

@@ -0,0 +1 @@
+f

test/fixtures/a/b/c/d/e/f/g/Mochafile.txt

@@ -0,0 +1 @@
+g

test/fixtures/a/b/c/d/e/f/g/h/Mochafile.txt

@@ -0,0 +1 @@
+h

test/fixtures/a/b/c/d/e/f/g/h/i/Mochafile.txt

@@ -0,0 +1 @@
+i

test/fixtures/a/b/c/d/e/f/g/h/i/j/Mochafile.txt

@@ -0,0 +1 @@
+j

test/test.js

@@ -15,6 +15,7 @@ var chdir = support.chdir;
 var npm = support.npm;
 var cwd;
 var actual;
+var isLinux = process.platform === 'linux';
 
 
 describe('findup-sync', function () {
@@ -56,6 +57,17 @@ describe('findup-sync', function () {
     restore();
   });
 
+  it('should find case sensitive files in a child directory', function () {
+    var expected = path.resolve(__dirname, 'fixtures/a/b/', (isLinux ? 'Mochafile.txt' : 'mochafile.txt'));
+    var restore = chdir(path.resolve(__dirname, 'fixtures/a/b/c/d/e/f/g/h'));
+
+    var actual = findup('a/b/mochafile.txt', {nocase: true});
+    assert(actual);
+    assert(exists(actual));
+    assert.equal(actual, expected);
+    restore();
+  });
+
   it('should find files in a child directory relative to a cwd', function () {
     var expectedFile = path.resolve(__dirname, 'fixtures/a/b/file.txt');
     var expectedA = path.resolve(__dirname, 'fixtures/a/a.txt');
@@ -73,6 +85,23 @@ describe('findup-sync', function () {
     tempDir();
   });
 
+  it('should find case sensitive files in a child directory relative to a cwd', function () {
+    var expectedFile = path.resolve(__dirname, 'fixtures/a/b', (isLinux ? 'Mochafile.txt' : 'mochafile.txt'));
+    var expectedA = path.resolve(__dirname, 'fixtures/a/a.txt');
+    var tempDir = chdir(path.resolve(__dirname, 'fixtures'));
+
+    var actualFile = findup('a/b/mochafile.txt', {cwd: 'a/b/c/d', nocase: true});
+    assert(actualFile);
+    assert(exists(actualFile));
+    assert.equal(actualFile, expectedFile);
+
+    var actualA = findup('a.txt', {cwd: 'a/b/c/d/e/f'});
+    assert(actualA);
+    assert(exists(actualA));
+    assert.equal(actualA, expectedA);
+    tempDir();
+  });
+
   it('should support normal (non-glob) file paths:', function () {
     var normPath = normalize(findup('package.json', {cwd: path.dirname(resolve.sync('normalize-path'))}));
     assert.equal(normPath, 'node_modules/normalize-path/package.json');
@@ -95,6 +124,12 @@ describe('findup-sync', function () {
     assert.basename(actual, 'package.json');
   });
 
+  it('should support normal (non-glob) case sensitive file paths:', function () {
+    actual = findup('c/mochafile.txt', {cwd: 'test/fixtures/a/b/c/d/e/f/g', nocase: true});
+    assert.basename(actual, (isLinux ? 'Mochafile.txt' : 'mochafile.txt'));
+    assert.dirname(actual, 'test/fixtures/a/b/c');
+  });
+
   it('should support glob patterns', function() {
     assert.equal(normalize(findup('**/c/package.json', {cwd: 'test/fixtures/a/b/c/d/e/f/g'})), 'test/fixtures/a/b/c/package.json');
     assert.equal(normalize(findup('**/one.txt', {cwd: 'test/fixtures/a/b/c/d/e/f/g'})), 'test/fixtures/a/b/c/d/one.txt');
@@ -127,6 +162,33 @@ describe('findup-sync', function () {
     assert.basename(actual, 'package.json');
   });
 
+  it('should support case sensitive glob patterns', function() {
+    assert.equal(normalize(findup('**/c/mochafile.txt', {cwd: 'test/fixtures/a/b/c/d/e/f/g', nocase: true})), 'test/fixtures/a/b/c/Mochafile.txt');
+    assert.equal(normalize(findup('**/one.txt', {cwd: 'test/fixtures/a/b/c/d/e/f/g', nocase: true})), 'test/fixtures/a/b/c/d/one.txt');
+    assert.equal(normalize(findup('**/two.txt', {cwd: 'test/fixtures/a/b/c/d/e/f/g', nocase: true})), 'test/fixtures/a/b/c/two.txt');
+
+    assert.equal(normalize(findup('mocha*', {cwd: 'test/fixtures/a/b/c', nocase: true})), 'test/fixtures/a/b/c/Mochafile.txt');
+
+    var opts = {cwd: 'test/fixtures/a/b/c/d/e/f/g', nocase: true};
+
+    actual = findup('**/c/mochafile.txt', opts);
+    assert.dirname(actual, 'test/fixtures/a/b/c');
+    assert.basename(actual, 'Mochafile.txt');
+
+    actual = findup('c/mochafile.txt', opts);
+    assert.dirname(actual, 'test/fixtures/a/b/c');
+    assert.basename(actual, (isLinux ? 'Mochafile.txt' : 'mochafile.txt'));
+
+    opts.nocase = false;
+    actual = findup('**/ONE.txt', opts);
+    assert.dirname(actual, 'test/fixtures/a/b/c');
+    assert.basename(actual, 'ONE.txt');
+
+    actual = findup('**/two.txt', opts);
+    assert.dirname(actual, 'test/fixtures/a/b/c');
+    assert.basename(actual, 'two.txt');
+  });
+
   it('should support arrays of glob patterns', function() {
     assert.equal(normalize(findup(['**/c/package.json'], {cwd: 'test/fixtures/a/b/c/d/e/f/g'})), 'test/fixtures/a/b/c/package.json');
     assert.equal(normalize(findup(['**/one.txt'], {cwd: 'test/fixtures/a/b/c/d/e/f/g'})), 'test/fixtures/a/b/c/d/one.txt');