fix: order components according to their index

Fixes #157

Author: metacosm

analysis/src/test/java/ComputeTest.java

@@ -3,10 +3,10 @@
 import java.util.Random;
 import java.util.random.RandomGenerator;
 
-import net.laprun.sustainability.power.SensorUnit;
 import org.junit.jupiter.api.Test;
 
 import net.laprun.sustainability.power.SensorMetadata;
+import net.laprun.sustainability.power.SensorUnit;
 import net.laprun.sustainability.power.analysis.Compute;
 import net.laprun.sustainability.power.analysis.MeanComponentProcessor;
 import net.laprun.sustainability.power.measure.OngoingPowerMeasure;

metadata/src/main/java/net/laprun/sustainability/power/SensorMetadata.java

@@ -4,7 +4,7 @@
 import java.util.BitSet;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -37,11 +37,11 @@ public SensorMetadata(List<ComponentMetadata> components, String documentation)
         }
 
         final var cardinality = components.size();
-        this.components = new HashMap<>(cardinality);
+        this.components = new LinkedHashMap<>(cardinality);
         this.documentation = documentation;
         final var errors = new Errors();
         final var indices = new BitSet(cardinality);
-        components.forEach(component -> {
+        components.stream().sorted(Comparator.comparingInt(ComponentMetadata::index)).forEach(component -> {
             // check that index is valid
             final var index = component.index;
             if (index < 0 || index >= cardinality) {

metadata/src/test/java/net/laprun/sustainability/power/SensorMetadataTest.java

@@ -71,4 +71,16 @@ void shouldFailIfNoComponentsAreProvided() {
                 () -> new SensorMetadata(List.of(), ""));
         assertEquals("Must provide at least one component", e2.getMessage());
     }
+
+    @Test
+    void shouldOrderComponentsByIndexOrder() {
+        final var metadata = new SensorMetadata(List.of(
+                new SensorMetadata.ComponentMetadata("foo", 1, null, true, SensorUnit.W),
+                new SensorMetadata.ComponentMetadata("component2", 0, null, true, SensorUnit.decimalPercentage)), "");
+
+        int i = 0;
+        for (var value : metadata.components().values()) {
+            assertEquals(i++, value.index());
+        }
+    }
 }