Internal builder for MetricOptions

docs/pages/pmd/devdocs/metrics_howto.md

@@ -78,7 +78,18 @@ Some metrics define options that can be used to slightly modify the computation.
 gathered inside an enum in the implementation class of the metric, for example `CycloMetric.CycloOptions`. They're 
 also documented on the [index of metrics](/pmd_java_metrics_index.html).
 
-To use options with a metric, you must first bundle them into a `MetricOptions`. 
+To use options with a metric, you must first bundle them into a `MetricOptions` object. `MetricOptions` provides the 
+utility method `toOptions(Collection<? extends MetricOption>)` to get a `MetricOptions`  bundle. You can then pass 
+this bundle as a parameter to `JavaMetrics.get`:
+```java
+public Object visit(ASTMethodDeclaration node, Object data) {
+  int cyclo = (int) JavaMetrics.get(JavaOperationMetricKey.CYCLO, node, MetricOptions.toOptions());
+  if (cyclo > 10) {
+      // add violation
+  }
+    return data;
+}
+```
 
 
 

pmd-apex/src/test/java/net/sourceforge/pmd/lang/apex/metrics/impl/AbstractApexMetricTestRule.java

@@ -97,7 +97,7 @@ public abstract class AbstractApexMetricTestRule extends AbstractApexRule {
     /**
      * Mappings of labels to options for use in the options property.
      *
-     * @return A map of labels to options
+     * @return A map of labels to options&
      */
     protected Map<String, MetricOption> optionMappings() {
         return new HashMap<>();

pmd-core/src/main/java/net/sourceforge/pmd/lang/metrics/MetricOptions.java

@@ -18,7 +18,7 @@ import java.util.Set;
  */
 public class MetricOptions {
 
-    private static final Map<MetricOptions, MetricOptions> POOL = new HashMap<>();
+    static final Map<MetricOptions, MetricOptions> POOL = new HashMap<>();
     private static final MetricOptions EMPTY_OPTIONS;
     private Set<MetricOption> options;
 
@@ -34,7 +34,7 @@ public class MetricOptions {
     }
 
 
-    private MetricOptions(Set<MetricOption> opts) {
+    private MetricOptions(Set<? extends MetricOption> opts) {
 
         switch (opts.size()) {
         case 0:
@@ -94,31 +94,81 @@ public class MetricOptions {
      *
      * @return An empty options bundle
      */
+
     public static MetricOptions emptyOptions() {
         return EMPTY_OPTIONS;
     }
 
 
     /**
-     * Gets an options bundle from a list of options.
+     * Gets an options bundle from a collection of options.
      *
-     * @param opts The options to build the bundle from
+     * @param options The options to build the bundle from
      *
      * @return An options bundle
      */
-    public static MetricOptions ofOptions(Collection<MetricOption> opts) {
-        MetricOptions version;
-        if (opts instanceof Set) {
-            version = new MetricOptions((Set<MetricOption>) opts);
-        } else {
-            version = new MetricOptions(new HashSet<>(opts));
-        }
-
-        if (!POOL.containsKey(version)) {
-            POOL.put(version, version);
-        }
-
-        return POOL.get(version);
+    public static MetricOptions ofOptions(Collection<? extends MetricOption> options) {
+        MetricOptionsBuilder builder = new MetricOptionsBuilder();
+        builder.addAll(options);
+        return builder.build();
     }
 
+
+    /**
+     * Gets an options bundle from options.
+     *
+     * @param option  Mandatory first argument
+     * @param options Rest of the options
+     *
+     * @return An options bundle
+     */
+    public static MetricOptions ofOptions(MetricOption option, MetricOption... options) {
+        MetricOptionsBuilder builder = new MetricOptionsBuilder();
+
+        builder.add(option);
+
+        for (MetricOption opt : options) {
+            builder.add(opt);
+        }
+
+        return builder.build();
+    }
+
+
+    private static class MetricOptionsBuilder {
+
+
+        private Set<MetricOption> opts = new HashSet<>();
+
+
+        void add(MetricOption option) {
+            if (option != null) {
+                opts.add(option);
+            }
+        }
+
+
+        void addAll(Collection<? extends MetricOption> options) {
+            if (options != null) {
+                this.opts.addAll(options);
+                opts.remove(null);
+            }
+        }
+
+
+        MetricOptions build() {
+            if (opts.size() == 0) {
+                return emptyOptions();
+            }
+
+            MetricOptions result = new MetricOptions(opts);
+
+            if (!POOL.containsKey(result)) {
+                POOL.put(result, result);
+            }
+
+            return POOL.get(result);
+        }
+
+    }
 }

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/metrics/rule/CyclomaticComplexityRule.java

@@ -45,7 +45,7 @@ public class CyclomaticComplexityRule extends AbstractJavaMetricsRule {
     }
 
 
-    private static final EnumeratedMultiProperty<MetricOption> CYCLO_VERSION_DESCRIPTOR = new EnumeratedMultiProperty<>(
+    private static final EnumeratedMultiProperty<MetricOption> CYCLO_OPTIONS_DESCRIPTOR = new EnumeratedMultiProperty<>(
         "cycloOptions", "Choose options for the computation of Cyclo",
         VERSION_MAP, Collections.<MetricOption>emptyList(), MetricOption.class, 3.0f);
 
@@ -57,7 +57,7 @@ public class CyclomaticComplexityRule extends AbstractJavaMetricsRule {
     public CyclomaticComplexityRule() {
         definePropertyDescriptor(CLASS_LEVEL_DESCRIPTOR);
         definePropertyDescriptor(METHOD_LEVEL_DESCRIPTOR);
-        definePropertyDescriptor(CYCLO_VERSION_DESCRIPTOR);
+        definePropertyDescriptor(CYCLO_OPTIONS_DESCRIPTOR);
     }
 
 
@@ -66,7 +66,7 @@ public class CyclomaticComplexityRule extends AbstractJavaMetricsRule {
         methodReportLevel = getProperty(METHOD_LEVEL_DESCRIPTOR);
         classReportLevel = getProperty(CLASS_LEVEL_DESCRIPTOR);
         if (cycloOptions == null) {
-            cycloOptions = MetricOptions.ofOptions(getProperty(CYCLO_VERSION_DESCRIPTOR));
+            cycloOptions = MetricOptions.ofOptions(getProperty(CYCLO_OPTIONS_DESCRIPTOR));
         }
 
         super.visit(node, data);

pmd-java/src/test/java/net/sourceforge/pmd/lang/java/metrics/ParameterizedMetricKeyTest.java

@@ -29,8 +29,8 @@ import net.sourceforge.pmd.lang.metrics.ParameterizedMetricKey;
  */
 public class ParameterizedMetricKeyTest {
 
-    private static final MetricOptions DUMMY_VERSION_1 = MetricOptions.ofOptions(Arrays.<MetricOption>asList(Options.DUMMY1, Options.DUMMY2));
-    private static final MetricOptions DUMMY_VERSION_2 = MetricOptions.ofOptions(Collections.<MetricOption>singleton(Options.DUMMY2));
+    private static final MetricOptions DUMMY_VERSION_1 = MetricOptions.ofOptions(Options.DUMMY1, Options.DUMMY2);
+    private static final MetricOptions DUMMY_VERSION_2 = MetricOptions.ofOptions(Options.DUMMY2);
 
     @Test
     public void testIdentity() {