feat: add metric value unit type (#580)

Author: dkrutskikh

CHANGELOG.md

@@ -6,6 +6,7 @@
 * feat: add support mixins, extensions and enums for `prefer-match-file-name` rule.
 * fix: prefer conditional expressions rule breaks code with increment / decrement operators.
 * fix: improve file metrics.
+* feat: add metric value unit type.
 * chore: restrict `analyzer` version to `>=2.4.0 <2.9.0`.
 * chore: tune GitHub workflows.
 

lib/src/analyzers/lint_analyzer/metrics/metrics_list/lines_of_code_metric.dart

@@ -62,4 +62,7 @@ class LinesOfCodeMetric extends FunctionMetric<int> {
       (threshold != null && value > threshold)
           ? 'Consider breaking this $nodeType up into smaller parts.'
           : null;
+
+  @override
+  String? unitType(int value) => value == 1 ? 'line' : 'lines';
 }

lib/src/analyzers/lint_analyzer/metrics/metrics_list/number_of_methods_metric.dart

@@ -77,4 +77,7 @@ class NumberOfMethodsMetric extends ClassMetric<int> {
                 location: nodeLocation(node: func.declaration, source: source),
               ))
           .toList(growable: false);
+
+  @override
+  String? unitType(int value) => value == 1 ? 'method' : 'methods';
 }

lib/src/analyzers/lint_analyzer/metrics/metrics_list/source_lines_of_code/source_lines_of_code_metric.dart

@@ -71,6 +71,9 @@ class SourceLinesOfCodeMetric extends FunctionMetric<int> {
           ? 'Consider breaking this $nodeType up into smaller parts.'
           : null;
 
+  @override
+  String? unitType(int value) => value == 1 ? 'line' : 'lines';
+
   Iterable<ContextMessage> _context(
     Iterable<int> linesWithCode,
     InternalResolvedUnitResult source,

lib/src/analyzers/lint_analyzer/metrics/models/metric.dart

@@ -65,6 +65,7 @@ abstract class Metric<T extends num> {
       metricsId: id,
       documentation: documentation,
       value: result.value,
+      unitType: unitType(result.value),
       level: _levelComputer(result.value, threshold),
       comment: commentMessage(type, result.value, threshold),
       recommendation: recommendationMessage(type, result.value, threshold),
@@ -98,4 +99,8 @@ abstract class Metric<T extends num> {
     Iterable<ScopedClassDeclaration> classDeclarations,
     Iterable<ScopedFunctionDeclaration> functionDeclarations,
   );
+
+  /// Returns the human readable unit type.
+  @protected
+  String? unitType(T value) => null;
 }

lib/src/analyzers/lint_analyzer/metrics/models/metric_value.dart

@@ -16,6 +16,9 @@ class MetricValue<T> {
   /// The actual value computed by the metric.
   final T value;
 
+  /// The human readable unit type.
+  final String? unitType;
+
   /// The level of this value computed by the metric.
   final MetricValueLevel level;
 
@@ -41,6 +44,7 @@ class MetricValue<T> {
     required this.metricsId,
     required this.documentation,
     required this.value,
+    this.unitType,
     required this.level,
     required this.comment,
     this.recommendation,

lib/src/analyzers/lint_analyzer/reporters/reporters_list/console/lint_console_reporter_helper.dart

@@ -57,9 +57,9 @@ class LintConsoleReporterHelper {
     final color = _colorPens[metric.level];
 
     if (color != null) {
-      final value = metric.value.toInt();
+      final value = '${metric.value.toInt()} ${metric.unitType ?? ''}'.trim();
 
-      return '${metric.documentation.name.toLowerCase()}: ${color('$value')}';
+      return '${metric.documentation.name.toLowerCase()}: ${color(value)}';
     }
 
     throw StateError('Unexpected violation level.');

lib/src/analyzers/lint_analyzer/reporters/reporters_list/html/components/report_details_tooltip.dart

@@ -38,7 +38,8 @@ Element renderDetailsTooltipMetric(MetricValue<num> metric) {
         ..attributes['rel'] = 'noopener noreferrer'
         ..attributes['title'] = metricName
         ..text = '$metricName:&nbsp;')
-      ..append(Element.tag('span')..text = metric.value.round().toString()))
+      ..append(Element.tag('span')
+        ..text = '${metric.value.round()} ${metric.unitType ?? ''}'.trim()))
     ..append(Element.tag('p')
       ..classes.add('metrics-source-code__tooltip-text')
       ..append(Element.tag('span')

lib/src/analyzers/lint_analyzer/reporters/reporters_list/json/lint_json_reporter.dart

@@ -100,11 +100,13 @@ class LintJsonReporter
     Iterable<MetricValue<num>> metrics,
   ) =>
       metrics.map((metric) {
+        final unitType = metric.unitType;
         final recommendation = metric.recommendation;
 
         return {
           'metricsId': metric.metricsId,
           'value': metric.value,
+          if (unitType != null) 'unitType': unitType,
           'level': metric.level.toString(),
           'comment': metric.comment,
           if (recommendation != null) 'recommendation': recommendation,

test/src/analyzers/lint_analyzer/metrics/metrics_list/lines_of_code_metric_test.dart

@@ -30,6 +30,7 @@ Future<void> main() async {
 
       expect(metricValue.metricsId, equals(metric.id));
       expect(metricValue.value, equals(5));
+      expect(metricValue.unitType, equals('lines'));
       expect(metricValue.level, equals(MetricValueLevel.noted));
       expect(
         metricValue.comment,
@@ -50,6 +51,7 @@ Future<void> main() async {
 
       expect(metricValue.metricsId, equals(metric.id));
       expect(metricValue.value, equals(2));
+      expect(metricValue.unitType, equals('lines'));
       expect(metricValue.level, equals(MetricValueLevel.none));
       expect(
         metricValue.comment,
@@ -70,6 +72,7 @@ Future<void> main() async {
 
       expect(metricValue.metricsId, equals(metric.id));
       expect(metricValue.value, equals(12));
+      expect(metricValue.unitType, equals('lines'));
       expect(metricValue.level, equals(MetricValueLevel.warning));
       expect(
         metricValue.comment,