sass.dart

// Copyright 2016 Google Inc. Use of this source code is governed by an
// MIT-style license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT.

import 'package:meta/meta.dart';
import 'package:package_config/package_config_types.dart';
import 'package:source_maps/source_maps.dart';

import 'src/async_import_cache.dart';
import 'src/callable.dart';
import 'src/compile.dart' as c;
import 'src/compile_result.dart';
import 'src/deprecation.dart';
import 'src/exception.dart';
import 'src/import_cache.dart';
import 'src/importer.dart';
import 'src/importer/utils.dart';
import 'src/logger.dart';
import 'src/syntax.dart';
import 'src/util/nullable.dart';
import 'src/visitor/serialize.dart';

export 'src/callable.dart' show Callable, AsyncCallable;
export 'src/compile_result.dart';
export 'src/deprecation.dart';
export 'src/exception.dart' show SassException;
export 'src/importer.dart';
export 'src/logger.dart' show Logger;
export 'src/syntax.dart';
export 'src/value.dart'
    hide
        ColorChannel,
        ColorFormat,
        LinearChannel,
        SassApiColorSpace,
        SpanColorFormat;
export 'src/visitor/serialize.dart' show OutputStyle;
export 'src/evaluation_context.dart' show warn;

/// Loads the Sass file at [path], compiles it to CSS, and returns a
/// [CompileResult] containing the CSS and additional metadata about the
/// compilation.
///
/// If [color] is `true`, this will use terminal colors in warnings. It's
/// ignored if [logger] is passed.
///
/// If [logger] is passed, it's used to emit all messages that are generated by
/// Sass code. Users may pass custom subclasses of [Logger].
///
/// Imports are resolved by trying, in order:
///
/// * Loading a file relative to [path].
///
/// * Each importer in [importers].
///
/// * Each load path in [loadPaths]. Note that this is a shorthand for adding
///   [FilesystemImporter]s to [importers].
///
/// * Each load path specified in the `SASS_PATH` environment variable, which
///   should be semicolon-separated on Windows and colon-separated elsewhere.
///
/// * `package:` resolution using [packageConfig], which is a
///   [`PackageConfig`][] from the `package_resolver` package. Note that
///   this is a shorthand for adding a [PackageImporter] to [importers].
///
/// [`PackageConfig`]: https://pub.dev/documentation/package_config/latest/package_config.package_config/PackageConfig-class.html
///
/// Dart functions that can be called from Sass may be passed using [functions].
/// Each [Callable] defines a top-level function that will be invoked when the
/// given name is called from Sass.
///
/// The [style] parameter controls the style of the resulting CSS.
///
/// If [quietDeps] is `true`, this will silence compiler warnings emitted for
/// stylesheets loaded through [importers], [loadPaths], or [packageConfig].
///
/// By default, once a deprecation warning for a given feature is printed five
/// times, further warnings for that feature are silenced. If [verbose] is true,
/// all deprecation warnings are printed instead.
///
/// If [sourceMap] is `true`, [CompileResult.sourceMap] will be set to a
/// [SingleMapping] that indicates which sections of the source file(s)
/// correspond to which in the resulting CSS. [SingleMapping.targetUrl] will be
/// `null`. It's up to the caller to save this mapping to disk and add a source
/// map comment to [CompileResult.css] pointing to it. Users using the
/// [SingleMapping] API should be sure to add the [`source_maps`][] package to
/// their pubspec.
///
/// [`source_maps`]: https://pub.dartlang.org/packages/source_maps
///
/// If [charset] is `true`, this will include a `@charset` declaration or a
/// UTF-8 [byte-order mark][] if the stylesheet contains any non-ASCII
/// characters. Otherwise, it will never include a `@charset` declaration or a
/// byte-order mark.
///
/// [byte-order mark]: https://en.wikipedia.org/wiki/Byte_order_mark#UTF-8
///
/// Throws a [SassException] if conversion fails.
///
/// {@category Compile}
CompileResult compileToResult(
  String path, {
  bool color = false,
  Logger? logger,
  Iterable<Importer>? importers,
  Iterable<String>? loadPaths,
  PackageConfig? packageConfig,
  Iterable<Callable>? functions,
  OutputStyle? style,
  bool quietDeps = false,
  bool verbose = false,
  bool sourceMap = false,
  bool charset = true,
  Iterable<Deprecation>? silenceDeprecations,
  Iterable<Deprecation>? fatalDeprecations,
  Iterable<Deprecation>? futureDeprecations,
}) =>
    c.compile(
      path,
      logger: logger,
      importCache: ImportCache(
        importers: importers,
        loadPaths: loadPaths,
        packageConfig: packageConfig,
      ),
      functions: functions,
      style: style,
      quietDeps: quietDeps,
      verbose: verbose,
      sourceMap: sourceMap,
      charset: charset,
      silenceDeprecations: silenceDeprecations,
      fatalDeprecations: fatalDeprecations,
      futureDeprecations: futureDeprecations,
    );

/// Compiles [source] to CSS and returns a [CompileResult] containing the CSS
/// and additional metadata about the compilation..
///
/// This parses the stylesheet as [syntax], which defaults to [Syntax.scss].
///
/// If [color] is `true`, this will use terminal colors in warnings. It's
/// ignored if [logger] is passed.
///
/// If [logger] is passed, it's used to emit all messages that are generated by
/// Sass code. Users may pass custom subclasses of [Logger].
///
/// Imports are resolved by trying, in order:
///
/// * The given [importer], with the imported URL resolved relative to [url].
///
/// * Each importer in [importers].
///
/// * Each load path in [loadPaths]. Note that this is a shorthand for adding
///   [FilesystemImporter]s to [importers].
///
/// * Each load path specified in the `SASS_PATH` environment variable, which
///   should be semicolon-separated on Windows and colon-separated elsewhere.
///
/// * `package:` resolution using [packageConfig], which is a
///   [`PackageConfig`][] from the `package_resolver` package. Note that
///   this is a shorthand for adding a [PackageImporter] to [importers].
///
/// [`PackageConfig`]: https://pub.dev/documentation/package_config/latest/package_config.package_config/PackageConfig-class.html
///
/// Dart functions that can be called from Sass may be passed using [functions].
/// Each [Callable] defines a top-level function that will be invoked when the
/// given name is called from Sass.
///
/// The [style] parameter controls the style of the resulting CSS.
///
/// The [url] indicates the location from which [source] was loaded. It may be a
/// [String] or a [Uri]. If [importer] is passed, [url] must be passed as well
/// and `importer.load(url)` should return `source`.
///
/// If [quietDeps] is `true`, this will silence compiler warnings emitted for
/// stylesheets loaded through [importers], [loadPaths], or [packageConfig].
///
/// By default, once a deprecation warning for a given feature is printed five
/// times, further warnings for that feature are silenced. If [verbose] is true,
/// all deprecation warnings are printed instead.
///
/// If [sourceMap] is `true`, [CompileResult.sourceMap] will be set to a
/// [SingleMapping] that indicates which sections of the source file(s)
/// correspond to which in the resulting CSS. [SingleMapping.targetUrl] will be
/// `null`. It's up to the caller to save this mapping to disk and add a source
/// map comment to [CompileResult.css] pointing to it. Users using the
/// [SingleMapping] API should be sure to add the [`source_maps`][] package to
/// their pubspec.
///
/// [`source_maps`]: https://pub.dartlang.org/packages/source_maps
///
/// If [charset] is `true`, this will include a `@charset` declaration or a
/// UTF-8 [byte-order mark][] if the stylesheet contains any non-ASCII
/// characters. Otherwise, it will never include a `@charset` declaration or a
/// byte-order mark.
///
/// [byte-order mark]: https://en.wikipedia.org/wiki/Byte_order_mark#UTF-8
///
/// Throws a [SassException] if conversion fails.
///
/// {@category Compile}
CompileResult compileStringToResult(
  String source, {
  Syntax? syntax,
  bool color = false,
  Logger? logger,
  Iterable<Importer>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<Callable>? functions,
  OutputStyle? style,
  Importer? importer,
  Object? url,
  bool quietDeps = false,
  bool verbose = false,
  bool sourceMap = false,
  bool charset = true,
  Iterable<Deprecation>? silenceDeprecations,
  Iterable<Deprecation>? fatalDeprecations,
  Iterable<Deprecation>? futureDeprecations,
}) =>
    c.compileString(
      source,
      syntax: syntax,
      logger: logger,
      importCache: ImportCache(
        importers: importers,
        packageConfig: packageConfig,
        loadPaths: loadPaths,
      ),
      functions: functions,
      style: style,
      importer: importer,
      url: url,
      quietDeps: quietDeps,
      verbose: verbose,
      sourceMap: sourceMap,
      charset: charset,
      silenceDeprecations: silenceDeprecations,
      fatalDeprecations: fatalDeprecations,
      futureDeprecations: futureDeprecations,
    );

/// Like [compileToResult], except it runs asynchronously.
///
/// Running asynchronously allows this to take [AsyncImporter]s rather than
/// synchronous [Importer]s. However, running asynchronously is also somewhat
/// slower, so [compileToResult] should be preferred if possible.
Future<CompileResult> compileToResultAsync(
  String path, {
  bool color = false,
  Logger? logger,
  Iterable<AsyncImporter>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<AsyncCallable>? functions,
  OutputStyle? style,
  bool quietDeps = false,
  bool verbose = false,
  bool sourceMap = false,
  bool charset = true,
  Iterable<Deprecation>? silenceDeprecations,
  Iterable<Deprecation>? fatalDeprecations,
  Iterable<Deprecation>? futureDeprecations,
}) =>
    c.compileAsync(
      path,
      logger: logger,
      importCache: AsyncImportCache(
        importers: importers,
        loadPaths: loadPaths,
        packageConfig: packageConfig,
      ),
      functions: functions,
      style: style,
      quietDeps: quietDeps,
      verbose: verbose,
      sourceMap: sourceMap,
      charset: charset,
      silenceDeprecations: silenceDeprecations,
      fatalDeprecations: fatalDeprecations,
      futureDeprecations: futureDeprecations,
    );

/// Like [compileStringToResult], except it runs asynchronously.
///
/// Running asynchronously allows this to take [AsyncImporter]s rather than
/// synchronous [Importer]s. However, running asynchronously is also somewhat
/// slower, so [compileStringToResult] should be preferred if possible.
///
/// {@category Compile}
Future<CompileResult> compileStringToResultAsync(
  String source, {
  Syntax? syntax,
  bool color = false,
  Logger? logger,
  Iterable<AsyncImporter>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<AsyncCallable>? functions,
  OutputStyle? style,
  AsyncImporter? importer,
  Object? url,
  bool quietDeps = false,
  bool verbose = false,
  bool sourceMap = false,
  bool charset = true,
  Iterable<Deprecation>? silenceDeprecations,
  Iterable<Deprecation>? fatalDeprecations,
  Iterable<Deprecation>? futureDeprecations,
}) =>
    c.compileStringAsync(
      source,
      syntax: syntax,
      logger: logger,
      importCache: AsyncImportCache(
        importers: importers,
        packageConfig: packageConfig,
        loadPaths: loadPaths,
      ),
      functions: functions,
      style: style,
      importer: importer,
      url: url,
      quietDeps: quietDeps,
      verbose: verbose,
      sourceMap: sourceMap,
      charset: charset,
      silenceDeprecations: silenceDeprecations,
      fatalDeprecations: fatalDeprecations,
      futureDeprecations: futureDeprecations,
    );

/// Like [compileToResult], but returns [CompileResult.css] rather than
/// returning [CompileResult] directly.
///
/// If [sourceMap] is passed, it's passed a [SingleMapping] that indicates which
/// sections of the source file(s) correspond to which in the resulting CSS.
/// It's called immediately before this method returns, and only if compilation
/// succeeds. Note that [SingleMapping.targetUrl] will always be `null`. Users
/// using the [SingleMapping] API should be sure to add the [`source_maps`][]
/// package to their pubspec.
///
/// [`source_maps`]: https://pub.dartlang.org/packages/source_maps
///
/// This parameter is meant to be used as an out parameter, so that users who
/// want access to the source map can get it. For example:
///
/// ```dart
/// SingleMapping sourceMap;
/// var css = compile(sassPath, sourceMap: (map) => sourceMap = map);
/// ```
///
/// {@category Compile}
@Deprecated("Use compileToResult() instead.")
String compile(
  String path, {
  bool color = false,
  Logger? logger,
  Iterable<Importer>? importers,
  Iterable<String>? loadPaths,
  PackageConfig? packageConfig,
  Iterable<Callable>? functions,
  OutputStyle? style,
  bool quietDeps = false,
  bool verbose = false,
  @Deprecated("Use CompileResult.sourceMap from compileToResult() instead.")
  void sourceMap(SingleMapping map)?,
  bool charset = true,
}) {
  var result = compileToResult(
    path,
    logger: logger,
    importers: importers,
    loadPaths: loadPaths,
    packageConfig: packageConfig,
    functions: functions,
    style: style,
    quietDeps: quietDeps,
    verbose: verbose,
    sourceMap: sourceMap != null,
    charset: charset,
  );
  result.sourceMap.andThen(sourceMap);
  return result.css;
}

/// Like [compileStringToResult], but returns [CompileResult.css] rather than
/// returning [CompileResult] directly.
///
/// If [sourceMap] is passed, it's passed a [SingleMapping] that indicates which
/// sections of the source file(s) correspond to which in the resulting CSS.
/// It's called immediately before this method returns, and only if compilation
/// succeeds. Note that [SingleMapping.targetUrl] will always be `null`. Users
/// using the [SingleMapping] API should be sure to add the [`source_maps`][]
/// package to their pubspec.
///
/// [`source_maps`]: https://pub.dartlang.org/packages/source_maps
///
/// This parameter is meant to be used as an out parameter, so that users who
/// want access to the source map can get it. For example:
///
/// ```dart
/// SingleMapping sourceMap;
/// var css = compileString(sass, sourceMap: (map) => sourceMap = map);
/// ```
///
/// {@category Compile}
@Deprecated("Use compileStringToResult() instead.")
String compileString(
  String source, {
  Syntax? syntax,
  bool color = false,
  Logger? logger,
  Iterable<Importer>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<Callable>? functions,
  OutputStyle? style,
  Importer? importer,
  Object? url,
  bool quietDeps = false,
  bool verbose = false,
  @Deprecated(
    "Use CompileResult.sourceMap from compileStringToResult() instead.",
  )
  void sourceMap(SingleMapping map)?,
  bool charset = true,
  @Deprecated("Use syntax instead.") bool indented = false,
}) {
  var result = compileStringToResult(
    source,
    syntax: syntax ?? (indented ? Syntax.sass : Syntax.scss),
    logger: logger,
    importers: importers,
    packageConfig: packageConfig,
    loadPaths: loadPaths,
    functions: functions,
    style: style,
    importer: importer,
    url: url,
    quietDeps: quietDeps,
    verbose: verbose,
    sourceMap: sourceMap != null,
    charset: charset,
  );
  result.sourceMap.andThen(sourceMap);
  return result.css;
}

/// Like [compile], except it runs asynchronously.
///
/// Running asynchronously allows this to take [AsyncImporter]s rather than
/// synchronous [Importer]s. However, running asynchronously is also somewhat
/// slower, so [compile] should be preferred if possible.
///
/// {@category Compile}
@Deprecated("Use compileToResultAsync() instead.")
Future<String> compileAsync(
  String path, {
  bool color = false,
  Logger? logger,
  Iterable<AsyncImporter>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<AsyncCallable>? functions,
  OutputStyle? style,
  bool quietDeps = false,
  bool verbose = false,
  @Deprecated(
    "Use CompileResult.sourceMap from compileToResultAsync() instead.",
  )
  void sourceMap(SingleMapping map)?,
}) async {
  var result = await compileToResultAsync(
    path,
    logger: logger,
    importers: importers,
    loadPaths: loadPaths,
    packageConfig: packageConfig,
    functions: functions,
    style: style,
    quietDeps: quietDeps,
    verbose: verbose,
    sourceMap: sourceMap != null,
  );
  result.sourceMap.andThen(sourceMap);
  return result.css;
}

/// Like [compileString], except it runs asynchronously.
///
/// Running asynchronously allows this to take [AsyncImporter]s rather than
/// synchronous [Importer]s. However, running asynchronously is also somewhat
/// slower, so [compileString] should be preferred if possible.
///
/// {@category Compile}
@Deprecated("Use compileStringToResultAsync() instead.")
Future<String> compileStringAsync(
  String source, {
  Syntax? syntax,
  bool color = false,
  Logger? logger,
  Iterable<AsyncImporter>? importers,
  PackageConfig? packageConfig,
  Iterable<String>? loadPaths,
  Iterable<AsyncCallable>? functions,
  OutputStyle? style,
  AsyncImporter? importer,
  Object? url,
  bool quietDeps = false,
  bool verbose = false,
  @Deprecated(
    "Use CompileResult.sourceMap from compileStringToResultAsync() instead.",
  )
  void sourceMap(SingleMapping map)?,
  bool charset = true,
  @Deprecated("Use syntax instead.") bool indented = false,
}) async {
  var result = await compileStringToResultAsync(
    source,
    syntax: syntax ?? (indented ? Syntax.sass : Syntax.scss),
    logger: logger,
    importers: importers,
    packageConfig: packageConfig,
    loadPaths: loadPaths,
    functions: functions,
    style: style,
    importer: importer,
    url: url,
    quietDeps: quietDeps,
    verbose: verbose,
    sourceMap: sourceMap != null,
    charset: charset,
  );
  result.sourceMap.andThen(sourceMap);
  return result.css;
}

/// Runs [callback] in a context where [AsyncImporter.fromImport] returns
/// `true`.
///
/// This is only intended for use when testing custom importers.
@visibleForTesting
T fakeFromImport<T>(T callback()) => inImportRule(callback);