Parse-time deprecation messages are not properly rate limited

[ntkme]

$ npx sass --version
1.80.0 compiled with dart2js 3.5.3

$ npx sass --no-verbose node_modules/bootstrap/scss/bootstrap.scss 2>&1 | grep 'Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.' | wc -l
      87

When compiling latest bootstrap, the same @import deprecation is printed 87 times, where it should only be printed 5 times and then get summarized.

[ntkme]

dart-sass/lib/src/import_cache.dart

Lines 360 to 379 in ab19f94

	/// Wraps [logger] to process deprecations within an ImportCache.
	///
	/// This wrapped logger will handle the deprecation options, but will not
	/// limit repetition, as it can be re-used across parses. A logger passed to
	/// an ImportCache or AsyncImportCache should generally be wrapped here first,
	/// unless it's already been wrapped to process deprecations, in which case
	/// this method has no effect.
	static DeprecationProcessingLogger wrapLogger(
	Logger? logger,
	Iterable<Deprecation>? silenceDeprecations,
	Iterable<Deprecation>? fatalDeprecations,
	Iterable<Deprecation>? futureDeprecations,
	{bool color = false}) {
	if (logger is DeprecationProcessingLogger) return logger;
	return DeprecationProcessingLogger(logger ?? Logger.stderr(color: color),
	silenceDeprecations: {...?silenceDeprecations},
	fatalDeprecations: {...?fatalDeprecations},
	futureDeprecations: {...?futureDeprecations},
	limitRepetition: false);
	}

@jathak This seems to be a deliberate choice but I'm afraid that this is way too noisy for large framework like bootstrap.

[nex3]

I agree that we should make sure this case uses a repetition-limiting logger. Probably from the CLI, we should manually construct a shared logger—or if we're running in watch mode, a separate shared logger for each batch of events.

[ntkme]

Probably from the CLI, we should manually construct a shared logger—or if we're running in watch mode, a separate shared logger for each batch of events.

In fact, we have the very same issue in both CLI and API due to the DeprecationProcessingLogger inside ImportCache is hard coded with limitRepetition: false. The JS API specifically mentions the behavior of verbose option here: https://sass-lang.com/documentation/js-api/interfaces/options/#verbose

By default, Dart Sass will print only five instances of the same deprecation warning per compilation to avoid deluging users in console noise. If you set verbose to true, it will instead print every deprecation warning it encounters.

[nex3]

After consulting with @jathak, the current plan here is to move away from emitting any deprecation warnings at parse time at all. Instead, the parser will accumulate a list of deprecations and attach it to a hidden field in the Stylesheet object, and the evaluator will then emit those warnings when the stylesheet is loaded. This will allow us to avoid needing to have the ImportCache handle a logger at all.

As a side effect of this, we can (Dart-level) deprecate the logger parameter to the ImportCache as well as various parse functions.