Only omit 5 deprecation warnings per feature by default

CHANGELOG.md

@@ -2,17 +2,26 @@
 
 * Don't emit the same warning in the same location multiple times.
 
+* Cap deprecation warnings at 5 per feature by default.
+
 ### Command Line Interface
 
 * Add a `--quiet-deps` flag which silences compiler warnings from stylesheets
   loaded through `--load-path`s.
 
+* Add a `--verbose` flag which causes the compiler to emit all deprecation
+  warnings, not just 5 per feature.
+
 ### Dart API
 
 * Add a `quietDeps` argument to `compile()`, `compileString()`,
   `compileAsync()`, and `compileStringAsync()` which silences compiler warnings
   from stylesheets loaded through importers, load paths, and `package:` URLs.
 
+* Add a `verbose` argument to `compile()`, `compileString()`, `compileAsync()`,
+  and `compileStringAsync()` which causes the compiler to emit all deprecation
+  warnings, not just 5 per feature.
+
 ## 1.33.0
 
 * Deprecate the use of `/` for division. The new `math.div()` function should be

lib/sass.dart

@@ -64,6 +64,10 @@ export 'src/warn.dart' show warn;
 /// 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 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
@@ -98,6 +102,7 @@ String compile(String path,
     Iterable<Callable>? functions,
     OutputStyle? style,
     bool quietDeps = false,
+    bool verbose = false,
     void sourceMap(SingleMapping map)?,
     bool charset = true}) {
   logger ??= Logger.stderr(color: color);
@@ -111,6 +116,7 @@ String compile(String path,
       functions: functions,
       style: style,
       quietDeps: quietDeps,
+      verbose: verbose,
       sourceMap: sourceMap != null,
       charset: charset);
   result.sourceMap.andThen(sourceMap);
@@ -158,6 +164,10 @@ String compile(String path,
 /// 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 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
@@ -195,6 +205,7 @@ String compileString(String source,
     Importer? importer,
     Object? url,
     bool quietDeps = false,
+    bool verbose = false,
     void sourceMap(SingleMapping map)?,
     bool charset = true,
     @Deprecated("Use syntax instead.") bool indented = false}) {
@@ -212,6 +223,7 @@ String compileString(String source,
       importer: importer,
       url: url,
       quietDeps: quietDeps,
+      verbose: verbose,
       sourceMap: sourceMap != null,
       charset: charset);
   result.sourceMap.andThen(sourceMap);
@@ -232,6 +244,7 @@ Future<String> compileAsync(String path,
     Iterable<AsyncCallable>? functions,
     OutputStyle? style,
     bool quietDeps = false,
+    bool verbose = false,
     void sourceMap(SingleMapping map)?}) async {
   logger ??= Logger.stderr(color: color);
   var result = await c.compileAsync(path,
@@ -244,6 +257,7 @@ Future<String> compileAsync(String path,
       functions: functions,
       style: style,
       quietDeps: quietDeps,
+      verbose: verbose,
       sourceMap: sourceMap != null);
   result.sourceMap.andThen(sourceMap);
   return result.css;
@@ -266,6 +280,7 @@ Future<String> compileStringAsync(String source,
     AsyncImporter? importer,
     Object? url,
     bool quietDeps = false,
+    bool verbose = false,
     void sourceMap(SingleMapping map)?,
     bool charset = true,
     @Deprecated("Use syntax instead.") bool indented = false}) async {
@@ -283,6 +298,7 @@ Future<String> compileStringAsync(String source,
       importer: importer,
       url: url,
       quietDeps: quietDeps,
+      verbose: verbose,
       sourceMap: sourceMap != null,
       charset: charset);
   result.sourceMap.andThen(sourceMap);

lib/src/async_compile.dart

@@ -15,6 +15,7 @@ import 'importer.dart';
 import 'importer/node.dart';
 import 'io.dart';
 import 'logger.dart';
+import 'logger/terse.dart';
 import 'syntax.dart';
 import 'utils.dart';
 import 'visitor/async_evaluate.dart';
@@ -35,8 +36,12 @@ Future<CompileResult> compileAsync(String path,
     int? indentWidth,
     LineFeed? lineFeed,
     bool quietDeps = false,
+    bool verbose = false,
     bool sourceMap = false,
     bool charset = true}) async {
+  TerseLogger? terseLogger;
+  if (!verbose) logger = terseLogger = TerseLogger(logger ?? Logger.stderr());
+
   // If the syntax is different than the importer would default to, we have to
   // parse the file manually and we can't store it in the cache.
   Stylesheet? stylesheet;
@@ -52,7 +57,7 @@ Future<CompileResult> compileAsync(String path,
         url: p.toUri(path), logger: logger);
   }
 
-  return await _compileStylesheet(
+  var result = await _compileStylesheet(
       stylesheet,
       logger,
       importCache,
@@ -66,6 +71,9 @@ Future<CompileResult> compileAsync(String path,
       quietDeps,
       sourceMap,
       charset);
+
+  terseLogger?.summarize(node: nodeImporter != null);
+  return result;
 }
 
 /// Like [compileStringAsync] in `lib/sass.dart`, but provides more options to
@@ -87,12 +95,16 @@ Future<CompileResult> compileStringAsync(String source,
     LineFeed? lineFeed,
     Object? url,
     bool quietDeps = false,
+    bool verbose = false,
     bool sourceMap = false,
     bool charset = true}) async {
+  TerseLogger? terseLogger;
+  if (!verbose) logger = terseLogger = TerseLogger(logger ?? Logger.stderr());
+
   var stylesheet =
       Stylesheet.parse(source, syntax ?? Syntax.scss, url: url, logger: logger);
 
-  return _compileStylesheet(
+  var result = await _compileStylesheet(
       stylesheet,
       logger,
       importCache,
@@ -106,6 +118,9 @@ Future<CompileResult> compileStringAsync(String source,
       quietDeps,
       sourceMap,
       charset);
+
+  terseLogger?.summarize(node: nodeImporter != null);
+  return result;
 }
 
 /// Compiles [stylesheet] and returns its result.

lib/src/compile.dart

@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_compile.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: bdf01f7ff8eea0efafa6c7c93920caf26e324f4e
+// Checksum: 8e813f2ead6e78899ce820e279983278809a7ea5
 //
 // ignore_for_file: unused_import
 
@@ -25,6 +25,7 @@ import 'importer.dart';
 import 'importer/node.dart';
 import 'io.dart';
 import 'logger.dart';
+import 'logger/terse.dart';
 import 'syntax.dart';
 import 'utils.dart';
 import 'visitor/evaluate.dart';
@@ -45,8 +46,12 @@ CompileResult compile(String path,
     int? indentWidth,
     LineFeed? lineFeed,
     bool quietDeps = false,
+    bool verbose = false,
     bool sourceMap = false,
     bool charset = true}) {
+  TerseLogger? terseLogger;
+  if (!verbose) logger = terseLogger = TerseLogger(logger ?? Logger.stderr());
+
   // If the syntax is different than the importer would default to, we have to
   // parse the file manually and we can't store it in the cache.
   Stylesheet? stylesheet;
@@ -62,7 +67,7 @@ CompileResult compile(String path,
         url: p.toUri(path), logger: logger);
   }
 
-  return _compileStylesheet(
+  var result = _compileStylesheet(
       stylesheet,
       logger,
       importCache,
@@ -76,6 +81,9 @@ CompileResult compile(String path,
       quietDeps,
       sourceMap,
       charset);
+
+  terseLogger?.summarize(node: nodeImporter != null);
+  return result;
 }
 
 /// Like [compileString] in `lib/sass.dart`, but provides more options to
@@ -97,12 +105,16 @@ CompileResult compileString(String source,
     LineFeed? lineFeed,
     Object? url,
     bool quietDeps = false,
+    bool verbose = false,
     bool sourceMap = false,
     bool charset = true}) {
+  TerseLogger? terseLogger;
+  if (!verbose) logger = terseLogger = TerseLogger(logger ?? Logger.stderr());
+
   var stylesheet =
       Stylesheet.parse(source, syntax ?? Syntax.scss, url: url, logger: logger);
 
-  return _compileStylesheet(
+  var result = _compileStylesheet(
       stylesheet,
       logger,
       importCache,
@@ -116,6 +128,9 @@ CompileResult compileString(String source,
       quietDeps,
       sourceMap,
       charset);
+
+  terseLogger?.summarize(node: nodeImporter != null);
+  return result;
 }
 
 /// Compiles [stylesheet] and returns its result.

lib/src/executable/compile_stylesheet.dart

@@ -69,6 +69,7 @@ Future<void> compileStylesheet(ExecutableOptions options, StylesheetGraph graph,
               importer: FilesystemImporter('.'),
               style: options.style,
               quietDeps: options.quietDeps,
+              verbose: options.verbose,
               sourceMap: options.emitSourceMap,
               charset: options.charset)
           : await compileAsync(source,
@@ -77,6 +78,7 @@ Future<void> compileStylesheet(ExecutableOptions options, StylesheetGraph graph,
               importCache: importCache,
               style: options.style,
               quietDeps: options.quietDeps,
+              verbose: options.verbose,
               sourceMap: options.emitSourceMap,
               charset: options.charset);
     } else {
@@ -88,6 +90,7 @@ Future<void> compileStylesheet(ExecutableOptions options, StylesheetGraph graph,
               importer: FilesystemImporter('.'),
               style: options.style,
               quietDeps: options.quietDeps,
+              verbose: options.verbose,
               sourceMap: options.emitSourceMap,
               charset: options.charset)
           : compile(source,
@@ -96,6 +99,7 @@ Future<void> compileStylesheet(ExecutableOptions options, StylesheetGraph graph,
               importCache: graph.importCache,
               style: options.style,
               quietDeps: options.quietDeps,
+              verbose: options.verbose,
               sourceMap: options.emitSourceMap,
               charset: options.charset);
     }

lib/src/executable/options.dart

@@ -102,6 +102,8 @@ class ExecutableOptions {
       ..addFlag('quiet-deps',
           help: "Don't print compiler warnings from dependencies.\n"
               "Stylesheets imported through load paths count as dependencies.")
+      ..addFlag('verbose',
+          help: "Print all deprecation warnings even when they're repetitive.")
       ..addFlag('trace', help: 'Print full Dart stack traces for exceptions.')
       ..addFlag('help',
           abbr: 'h', help: 'Print this usage information.', negatable: false)
@@ -172,6 +174,9 @@ class ExecutableOptions {
   /// Whether to silence warnings in dependencies.
   bool get quietDeps => _options['quiet-deps'] as bool;
 
+  /// Whether to emit all repetitive deprecation warnings.
+  bool get verbose => _options['verbose'] as bool;
+
   /// The logger to use to emit messages from Sass.
   Logger get logger => quiet ? Logger.quiet : Logger.stderr(color: color);
 

lib/src/logger/terse.dart

@@ -0,0 +1,58 @@
+// Copyright 2018 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:collection/collection.dart';
+import 'package:source_span/source_span.dart';
+import 'package:stack_trace/stack_trace.dart';
+
+import '../logger.dart';
+
+/// The maximum number of repetitions of the same warning [TerseLogger] will
+/// emit before hiding the rest.
+const _maxRepetitions = 5;
+
+/// A logger that wraps an inner logger to omit repeated deprecation warnings.
+///
+/// A warning is considered "repeated" if the first paragraph is the same as
+/// another warning that's already been emitted.
+class TerseLogger implements Logger {
+  /// A map from the first paragraph of a warning to the number of times this
+  /// logger has emitted a warning with that line.
+  final _warningCounts = <String, int>{};
+
+  final Logger _inner;
+
+  TerseLogger(this._inner);
+
+  void warn(String message,
+      {FileSpan? span, Trace? trace, bool deprecation = false}) {
+    if (deprecation) {
+      var firstParagraph = message.split("\n\n").first;
+      var count = _warningCounts[firstParagraph] =
+          (_warningCounts[firstParagraph] ?? 0) + 1;
+      if (count > _maxRepetitions) return;
+    }
+
+    _inner.warn(message, span: span, trace: trace, deprecation: deprecation);
+  }
+
+  void debug(String message, SourceSpan span) => _inner.debug(message, span);
+
+  /// Prints a warning indicating the number of deprecation warnings that were
+  /// omitted.
+  ///
+  /// The [node] flag indicates whether this is running in Node.js mode, in
+  /// which case it doesn't mention "verbose mode" because the Node API doesn't
+  /// support that.
+  void summarize({required bool node}) {
+    var total = _warningCounts.values
+        .where((count) => count > _maxRepetitions)
+        .map((count) => count - _maxRepetitions)
+        .sum;
+    if (total > 0) {
+      _inner.warn("$total repetitive deprecation warnings omitted." +
+          (node ? "" : "\nRun in verbose mode to see all warnings."));
+    }
+  }
+}

lib/src/parse/scss.dart

@@ -48,7 +48,8 @@ class ScssParser extends StylesheetParser {
         logger.warn(
             '@elseif is deprecated and will not be supported in future Sass '
             'versions.\n'
-            'Use "@else if" instead.',
+            '\n'
+            'Recommendation: @else if',
             span: scanner.spanFrom(beforeAt),
             deprecation: true);
         scanner.position -= 2;

lib/src/parse/stylesheet.dart

@@ -1334,10 +1334,13 @@ abstract class StylesheetParser extends Parser {
     var value = buffer.interpolation(scanner.spanFrom(valueStart));
     return _withChildren(_statement, start, (children, span) {
       if (needsDeprecationWarning) {
-        logger.warn("""
-@-moz-document is deprecated and support will be removed from Sass in a future
-release. For details, see http://bit.ly/moz-document.
-""", span: span, deprecation: true);
+        logger.warn(
+            "@-moz-document is deprecated and support will be removed in Dart "
+            "Sass 2.0.0.\n"
+            "\n"
+            "For details, see http://bit.ly/moz-document.",
+            span: span,
+            deprecation: true);
       }
 
       return AtRule(name, span, value: value, children: children);