Create a directory for CSS output if necessary (#291)

Closes #288

CHANGELOG.md

@@ -1,6 +1,7 @@
-## 1.1.2
+## 1.2.0
 
-* Internal changes only.
+* The command-line executable will now create the directory for the resulting
+  CSS if that directory doesn't exist.
 
 ## 1.1.1
 

lib/src/executable.dart

@@ -111,6 +111,7 @@ main(List<String> args) async {
     }
 
     if (destination != null) {
+      ensureDir(p.dirname(destination));
       writeFile(destination, css + "\n");
     } else if (css.isNotEmpty) {
       print(css);

lib/src/io/interface.dart

@@ -61,5 +61,9 @@ bool fileExists(String path) => null;
 /// Returns whether a dir at [path] exists.
 bool dirExists(String path) => null;
 
+/// Ensures that a directory exists at [path], creating it and its ancestors if
+/// necessary.
+void ensureDir(String path) => null;
+
 /// Gets and sets the exit code that the process will use when it exits.
 int exitCode;

lib/src/io/node.dart

@@ -17,6 +17,7 @@ class _FS {
   external readFileSync(String path, [String encoding]);
   external void writeFileSync(String path, String data);
   external bool existsSync(String path);
+  external void mkdirSync(String path);
 }
 
 @JS()
@@ -93,25 +94,11 @@ String readFile(String path) {
 }
 
 /// Wraps `fs.readFileSync` to throw a [FileSystemException].
-_readFile(String path, [String encoding]) {
-  try {
-    return _fs.readFileSync(path, encoding);
-  } catch (error) {
-    var systemError = error as _SystemError;
-    throw new FileSystemException._(
-        _cleanErrorMessage(systemError), systemError.path);
-  }
-}
+_readFile(String path, [String encoding]) =>
+    _systemErrorToFileSystemException(() => _fs.readFileSync(path, encoding));
 
-void writeFile(String path, String contents) {
-  try {
-    return _fs.writeFileSync(path, contents);
-  } catch (error) {
-    var systemError = error as _SystemError;
-    throw new FileSystemException._(
-        _cleanErrorMessage(systemError), systemError.path);
-  }
-}
+void writeFile(String path, String contents) =>
+    _systemErrorToFileSystemException(() => _fs.writeFileSync(path, contents));
 
 Future<String> readStdin() async {
   var completer = new Completer<String>();
@@ -152,6 +139,32 @@ bool fileExists(String path) => _fs.existsSync(path);
 
 bool dirExists(String path) => _fs.existsSync(path);
 
+void ensureDir(String path) {
+  return _systemErrorToFileSystemException(() {
+    try {
+      _fs.mkdirSync(path);
+    } catch (error) {
+      var systemError = error as _SystemError;
+      if (systemError.code == 'EEXIST') return;
+      if (systemError.code != 'ENOENT') rethrow;
+      ensureDir(p.dirname(path));
+      _fs.mkdirSync(path);
+    }
+  });
+}
+
+/// Runs callback and converts any [_SystemError]s it throws into
+/// [FileSystemException]s.
+T _systemErrorToFileSystemException<T>(T callback()) {
+  try {
+    return callback();
+  } catch (error) {
+    var systemError = error as _SystemError;
+    throw new FileSystemException._(
+        _cleanErrorMessage(systemError), systemError.path);
+  }
+}
+
 @JS("process.stderr")
 external _Stderr get _stderr;
 

lib/src/io/vm.dart

@@ -53,3 +53,6 @@ Future<String> readStdin() async {
 bool fileExists(String path) => new io.File(path).existsSync();
 
 bool dirExists(String path) => new io.Directory(path).existsSync();
+
+void ensureDir(String path) =>
+    new io.Directory(path).createSync(recursive: true);

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.1.2
+version: 1.2.0-dev
 description: A Sass implementation in Dart.
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/sass/dart-sass

test/cli_shared.dart

@@ -51,6 +51,17 @@ void sharedTests(Future<TestProcess> runSass(Iterable<String> arguments)) {
     await d.file("out.css", equalsIgnoringWhitespace("a { b: 3; }")).validate();
   });
 
+  test("creates directories if necessary", () async {
+    await d.file("test.scss", "a {b: 1 + 2}").create();
+
+    var sass = await runSass(["test.scss", "some/new/dir/out.css"]);
+    expect(sass.stdout, emitsDone);
+    await sass.shouldExit(0);
+    await d
+        .file("some/new/dir/out.css", equalsIgnoringWhitespace("a { b: 3; }"))
+        .validate();
+  });
+
   test("compiles from stdin with the magic path -", () async {
     var sass = await runSass(["-"]);
     sass.stdin.writeln("a {b: 1 + 2}");