fix: npe when no coverage is reported

.gitignore

@@ -29,3 +29,5 @@ sonar-example-plugin.iml
 .project
 .settings/
 .scannerwork
+report.xml
+coverage.xml

pom.xml

@@ -5,7 +5,7 @@
   <groupId>com.github.kronenthaler.sonarqube.plugins.coveragevariation</groupId>
   <artifactId>sonar-coveragevariation-plugin</artifactId>
   <packaging>sonar-plugin</packaging>
-  <version>3.0.2</version>
+  <version>3.0.3</version>
 
   <name>Coverage Variation Plugin for SonarQube 9.x</name>
   <description>Plugin calculates the variation of the coverage between the current scan and the main branch's coverage</description>

src/main/java/com/github/kronenthaler/sonarqube/plugins/coveragevariation/measures/CoverageVariation.java

@@ -1,6 +1,7 @@
 package com.github.kronenthaler.sonarqube.plugins.coveragevariation.measures;
 
 import org.sonar.api.ce.measure.Component;
+import org.sonar.api.ce.measure.Measure;
 import org.sonar.api.ce.measure.MeasureComputer;
 import org.sonar.api.measures.CoreMetrics;
 import org.sonar.api.server.ServerSide;
@@ -19,7 +20,7 @@ public class CoverageVariation implements MeasureComputer {
   public MeasureComputerDefinition define(MeasureComputerDefinitionContext def) {
     return def.newDefinitionBuilder()
         .setInputMetrics(CoreMetrics.COVERAGE.getKey(), CoverageVariationMetrics.PREVIOUS_COVERAGE.key())
-        .setOutputMetrics(CoverageVariationMetrics.COVERAGE_VARIATION.key())
+        .setOutputMetrics(CoverageVariationMetrics.COVERAGE_VARIATION.key(), CoverageVariationMetrics.NEW_COVERAGE_VARIATION.key())
         .build();
   }
 
@@ -31,9 +32,12 @@ public void compute(MeasureComputerContext context) {
       return;
     }
 
-    Double scanCoverage = context.getMeasure(CoreMetrics.COVERAGE.getKey()).getDoubleValue();
-    Double currentCoverage = context.getMeasure(CoverageVariationMetrics.PREVIOUS_COVERAGE.getKey()).getDoubleValue();
+    Measure scanCoverageMeasure = context.getMeasure(CoreMetrics.COVERAGE.getKey());
+    Measure currentCoverageMeasure = context.getMeasure(CoverageVariationMetrics.PREVIOUS_COVERAGE.getKey());
+    Double scanCoverage = scanCoverageMeasure != null ? scanCoverageMeasure.getDoubleValue() : 0.0;
+    Double currentCoverage = currentCoverageMeasure != null ? currentCoverageMeasure.getDoubleValue() : 0.0;
     context.addMeasure(CoverageVariationMetrics.COVERAGE_VARIATION.key(), scanCoverage - currentCoverage);
+    context.addMeasure(CoverageVariationMetrics.NEW_COVERAGE_VARIATION.key(), scanCoverage - currentCoverage);
 
     // for debug purposes
     log.info("-------------------------------------------------------------");

src/main/java/com/github/kronenthaler/sonarqube/plugins/coveragevariation/measures/CoverageVariationMetrics.java

@@ -18,6 +18,15 @@ public class CoverageVariationMetrics implements Metrics {
       .setDescription("Difference of the current coverage vs the on new code coverage.")
       .setDirection(Metric.DIRECTION_NONE)
       .setQualitative(false)
+      .setHidden(false)
+      .setDomain(CoreMetrics.DOMAIN_COVERAGE)
+      .create();
+
+  public static final Metric<Double> NEW_COVERAGE_VARIATION = new Metric.Builder("new_coverage_variation", "Coverage variation", Metric.ValueType.PERCENT)
+      .setDescription("Difference of the current overall coverage vs the on new code overall coverage on branches and pull requests.")
+      .setDirection(Metric.DIRECTION_NONE)
+      .setQualitative(false)
+      .setHidden(false)
       .setDomain(CoreMetrics.DOMAIN_COVERAGE)
       .create();
 
@@ -31,6 +40,6 @@ public class CoverageVariationMetrics implements Metrics {
 
   @Override
   public List<Metric> getMetrics() {
-    return asList(COVERAGE_VARIATION, PREVIOUS_COVERAGE);
+    return asList(NEW_COVERAGE_VARIATION, COVERAGE_VARIATION, PREVIOUS_COVERAGE);
   }
 }

src/main/python/test2.py

@@ -6,3 +6,9 @@ def __init__(self):
     def f(self):
         z = self.y * self.x
         return z
+
+    def y2(self):
+        return self.y * self.y
+
+    def x2(self):
+        return self.x * self.x

src/test/java/com/github/kronenthaler/sonarqube/plugins/coveragevariation/tests/CoverageVariationTests.java

@@ -51,6 +51,26 @@ public void testComputeOnProject() {
     verify(context, times(1)).addMeasure(CoverageVariationMetrics.COVERAGE_VARIATION.key(), -1.0);
   }
 
+  @Test
+  public void testComputeOnProjectWithNoCoverageReported() {
+    Component component = mock(Component.class);
+    when(component.getType()).thenReturn(Component.Type.PROJECT);
+
+    Measure previousMeasure = mock(Measure.class);
+    when(previousMeasure.getDoubleValue()).thenReturn(90.0);
+
+    MeasureComputer.MeasureComputerContext context = mock(MeasureComputer.MeasureComputerContext.class);
+    when(context.getComponent()).thenReturn(component);
+    when(context.getMeasure(CoverageVariationMetrics.PREVIOUS_COVERAGE.getKey())).thenReturn(previousMeasure);
+    when(context.getMeasure(CoreMetrics.COVERAGE.getKey())).thenReturn(null);
+    doNothing().when(context).addMeasure(isA(String.class), isA(Double.class));
+
+    CoverageVariation target = new CoverageVariation();
+    target.compute(context);
+
+    verify(context, times(1)).addMeasure(CoverageVariationMetrics.COVERAGE_VARIATION.key(), -90.0);
+  }
+
   @Test
   public void testComputeSensorDisabled() {
     Component component = mock(Component.class);