simple test()

README.md

@@ -218,6 +218,21 @@ mkdir('-p', ['/tmp/a/b/c/d', '/tmp/e/f/g']); // same as above
 
 Creates directories.
 
+#### test(expression)
+Available expression primaries:
+
++ `'-d', 'path'`: true if path is a directory
++ `'-f', 'path'`: true if path is a regular file
+
+Examples:
+
+```javascript
+if (test('-d', path)) { /* do something with dir */ };
+if (!test('-f', path)) continue; // skip if it's a regular file
+```
+
+Evaluates expression using the available primaries and returns corresponding value.
+
 #### cat(file [, file ...])
 #### cat(file_array)
 

shell.js

@@ -57,6 +57,7 @@ function _pwd(options) {
 };
 exports.pwd = wrap('pwd', _pwd);
 
+
 //@
 //@ #### ls([options ,] path [,path ...])
 //@ #### ls([options ,] path_array)
@@ -486,6 +487,42 @@ function _mkdir(options, dirs) {
 }; // mkdir
 exports.mkdir = wrap('mkdir', _mkdir);
 
+//@
+//@ #### test(expression)
+//@ Available expression primaries:
+//@
+//@ + `'-d', 'path'`: true if path is a directory
+//@ + `'-f', 'path'`: true if path is a regular file
+//@
+//@ Examples:
+//@
+//@ ```javascript
+//@ if (test('-d', path)) { /* do something with dir */ };
+//@ if (!test('-f', path)) continue; // skip if it's a regular file
+//@ ```
+//@
+//@ Evaluates expression using the available primaries and returns corresponding value.
+function _test(options, path) {
+  if (!path)
+    error('no path given');
+
+  // hack - only works with unary primaries
+  options = parseOptions(options, {
+    'd': 'directory',
+    'f': 'file'
+  });
+  if (!options.directory && !options.file)
+    error('could not interpret expression');
+
+  if (options.directory)
+    return fs.existsSync(path) && fs.statSync(path).isDirectory();
+
+  if (options.file)
+    return fs.existsSync(path) && fs.statSync(path).isFile();
+}; // test
+exports.test = wrap('test', _test);
+
+
 //@
 //@ #### cat(file [, file ...])
 //@ #### cat(file_array)

test/test.js

@@ -0,0 +1,51 @@
+var shell = require('..');
+
+var assert = require('assert'),
+    path = require('path'),
+    fs = require('fs');
+
+// Node shims for < v0.7
+fs.existsSync = fs.existsSync || path.existsSync;
+
+shell.silent();
+
+shell.rm('-rf', 'tmp');
+shell.mkdir('tmp')
+
+//
+// Invalids
+//
+
+var result = shell.test(); // no expression given
+assert.ok(shell.error());
+
+var result = shell.test('asdf'); // bad expression
+assert.ok(shell.error());
+
+var result = shell.test('f', 'resources/file1'); // bad expression
+assert.ok(shell.error());
+
+var result = shell.test('-f'); // no file
+assert.ok(shell.error());
+
+//
+// Valids
+//
+
+var result = shell.test('-f', 'resources/file1');
+assert.equal(shell.error(), null);
+assert.equal(result, true);
+
+var result = shell.test('-d', 'resources/file1');
+assert.equal(shell.error(), null);
+assert.equal(result, false);
+
+var result = shell.test('-f', 'resources');
+assert.equal(shell.error(), null);
+assert.equal(result, false);
+
+var result = shell.test('-d', 'resources');
+assert.equal(shell.error(), null);
+assert.equal(result, true);
+
+shell.exit(123);