add coverage check (#1162)

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

CONTRIBUTING.md

@@ -17,14 +17,18 @@ This repository uses [Google Java Format](https://github.com/google/google-java-
 
 Run `./mvnw spotless:apply` to format the code (only changed files) before committing.
 
-Use `-Dspotless.check.skip=true` to skip the formatting check during development.
-
 ## Running Tests
 
 If you're getting errors when running tests:
 
 - Make sure that the IDE uses only the "Maven Shade" dependency of "prometheus-metrics-exposition-formats" and the "prometheus-metrics-tracer*" dependencies.
-
+
+### Avoid failures while running tests
+
+- Use `-Dspotless.check.skip=true` to skip the formatting check during development.
+- Use `-Dcoverage.skip=true` to skip the coverage check during development.
+- Use `-Dwarnings=-nowarn` to skip the warnings during development.
+
 ## Updating the Protobuf Java Classes
 
 Use `PROTO_GENERATION=true mvn clean install` to generate protobuf classes.

benchmarks/pom.xml

@@ -20,7 +20,7 @@
         <jmh.version>1.37</jmh.version>
         <simpleclient.version>0.16.0</simpleclient.version>
         <codahale.version>3.0.2</codahale.version>
-        <jacoco.line-coverage>0.0</jacoco.line-coverage>
+        <coverage.skip>true</coverage.skip>
     </properties>
 
     <dependencyManagement>

examples/pom.xml

@@ -17,7 +17,7 @@
     </description>
 
     <properties>
-        <jacoco.line-coverage>0.0</jacoco.line-coverage>
+        <coverage.skip>true</coverage.skip>
     </properties>
 
     <modules>

integration-tests/pom.xml

@@ -19,7 +19,7 @@
     </description>
 
     <properties>
-        <jacoco.line-coverage>0.0</jacoco.line-coverage>
+        <coverage.skip>true</coverage.skip>
     </properties>
 
     <modules>

pom.xml

@@ -21,6 +21,8 @@
         <otel.instrumentation.version>2.8.0-alpha</otel.instrumentation.version>
         <java.version>8</java.version>
         <jacoco.line-coverage>0.70</jacoco.line-coverage>
+        <coverage.skip>false</coverage.skip>
+        <warnings>-Werror</warnings>
     </properties>
 
     <licenses>
@@ -227,6 +229,7 @@
                 <artifactId>jacoco-maven-plugin</artifactId>
                 <version>0.8.12</version>
                 <configuration>
+                    <skip>${coverage.skip}</skip>
                     <excludes>
                         <exclude>**/generated/**</exclude>
                     </excludes>
@@ -309,8 +312,8 @@
                     <target>${java.version}</target>
                     <showWarnings>true</showWarnings>
                     <compilerArgs>
-                        <arg>-Xlint:all,-serial,-processing</arg>
-                        <arg>-Werror</arg>
+                        <arg>-Xlint:all,-serial,-processing,-options</arg>
+                        <arg>${warnings}</arg>
                         <arg>-XDcompilePolicy=simple</arg>
                         <arg>
                             -Xplugin:ErrorProne

prometheus-metrics-exporter-opentelemetry/pom.xml

@@ -19,8 +19,6 @@
 
     <properties>
         <automatic.module.name>io.prometheus.metrics.exporter.opentelemetry</automatic.module.name>
-        <!-- todo: add tests -->
-        <jacoco.line-coverage>0.0</jacoco.line-coverage>
     </properties>
 
     <dependencyManagement>
@@ -96,6 +94,11 @@
             <version>1.7.1-alpha</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.opentelemetry</groupId>
+            <artifactId>opentelemetry-sdk-testing</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusInfo.java

@@ -10,6 +10,7 @@
 import java.util.List;
 import java.util.stream.Collectors;
 
+@SuppressWarnings("this-escape")
 public class PrometheusInfo extends PrometheusData<DoublePointData>
     implements SumData<DoublePointData> {
 

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusMetricData.java

@@ -48,7 +48,7 @@ private String getNameWithoutUnit(MetricMetadata metricMetadata) {
 
   // See
   // https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/6cf4dec6cb42d87d8840e9f67d4acf66d4eb8fda/pkg/translator/prometheus/normalize_name.go#L19
-  private String convertUnit(Unit unit) {
+  static String convertUnit(Unit unit) {
     if (unit == null) {
       return null;
     }

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusStateSet.java

@@ -16,6 +16,7 @@ public class PrometheusStateSet extends PrometheusData<DoublePointData>
 
   private final List<DoublePointData> points;
 
+  @SuppressWarnings("this-escape")
   public PrometheusStateSet(StateSetSnapshot snapshot, long currentTimeMillis) {
     super(MetricDataType.DOUBLE_SUM);
     this.points = new ArrayList<>();