test(fs): add test for fs.writeFile

tests/Resources/fs.addontest.js

@@ -5,7 +5,6 @@
  * Please see the LICENSE included with this distribution for details.
  */
 /* eslint-env mocha */
-/* global Ti */
 /* eslint no-unused-expressions: "off" */
 'use strict';
 const should = require('./utilities/assertions');
@@ -849,7 +848,93 @@ describe('fs', function () {
 		});
 	});
 
-	// TODO: #writeFile()
+	describe('#writeFile()', () => {
+		it('is a function', () => {
+			should(fs.writeFile).be.a.Function;
+		});
+
+		it('writes a string to a non-existent file', finish => {
+			const filename = path.join(Ti.Filesystem.tempDirectory, `writeFile${Date.now()}.txt`);
+			// ensure parent dir exists
+			should(fs.existsSync(Ti.Filesystem.tempDirectory)).eql(true);
+			// ensure file does not
+			should(fs.existsSync(filename)).eql(false);
+			const contents = 'Hello World!';
+			fs.writeFile(filename, contents, err => {
+				try {
+					should(err).not.exist;
+					// file should now exist
+					should(fs.existsSync(filename)).eql(true);
+					// contents should match what we wrote
+					should(fs.readFileSync(filename, 'utf-8')).eql(contents);
+				} catch (e) {
+					return finish(e);
+				}
+				finish();
+			});
+		});
+
+		it('writes a string to existing file, replaces it', finish => {
+			const filename = path.join(Ti.Filesystem.tempDirectory, `writeFile${Date.now()}.txt`);
+			// ensure parent dir exists
+			should(fs.existsSync(Ti.Filesystem.tempDirectory)).eql(true);
+			// ensure file does not
+			should(fs.existsSync(filename)).eql(false);
+			const contents = 'Hello World!';
+			fs.writeFile(filename, contents, err => {
+				try {
+					should(err).not.exist;
+
+					// file should now exist
+					should(fs.existsSync(filename)).eql(true); // FIXME: fails on Android
+					// contents should match what we wrote
+					should(fs.readFileSync(filename, 'utf-8')).eql(contents);
+
+					// Now replace it's contents by writing again
+					const contents2 = 'I replaced you!';
+					fs.writeFile(filename, contents2, err2 => {
+						try {
+							should(err2).not.exist;
+							// contents should match what we wrote
+							should(fs.readFileSync(filename, 'utf-8')).eql(contents2);
+						} catch (e) {
+							return finish(e);
+						}
+						finish();
+					});
+				} catch (e) {
+					return finish(e);
+				}
+			});
+		});
+
+		it('throws if trying to write to path of an existing directory', finish => {
+			const dirname = path.join(Ti.Filesystem.tempDirectory, `writeFile_d_${Date.now()}`);
+			fs.mkdirSync(dirname);
+			// ensure dir exists
+			should(fs.existsSync(dirname)).eql(true);
+
+			fs.writeFile(dirname, 'Hello World!', error => {
+				try {
+					should(error).exist;
+					// verify error
+					error.name.should.eql('Error');
+					error.message.should.eql(`EISDIR: illegal operation on a directory, open '${dirname}'`);
+					error.errno.should.eql(-21);
+					error.syscall.should.eql('open');
+					error.code.should.eql('EISDIR');
+					error.path.should.eql(dirname);
+				} catch (e) {
+					return finish(e);
+				}
+				finish();
+			});
+		});
+
+		// TODO: What if parent dir does not exist?
+		// TODO: what if target path exists but is a directory?
+		// TODO: What if data is a Buffer?
+	});
 
 	describe('#writeFileSync()', () => {
 		it('is a function', () => {