fix: keep typed descriptors opt-in for legacy snapshots

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

Author: zeitlinger

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/CounterSnapshot.java

@@ -179,14 +179,6 @@ public Builder dataPoint(CounterDataPointSnapshot dataPoint) {
       return this;
     }
 
-    @Override
-    protected MetricMetadata buildMetadata() {
-      if (name == null) {
-        throw new IllegalArgumentException("Missing required field: name is null");
-      }
-      return MetricMetadataSupport.counterMetadata(name, help, unit);
-    }
-
     @Override
     public CounterSnapshot build() {
       return new CounterSnapshot(buildMetadata(), dataPoints);

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java

@@ -118,14 +118,6 @@ public Builder unit(@Nullable Unit unit) {
       throw new IllegalArgumentException("Info metric cannot have a unit.");
     }
 
-    @Override
-    protected MetricMetadata buildMetadata() {
-      if (name == null) {
-        throw new IllegalArgumentException("Missing required field: name is null");
-      }
-      return MetricMetadataSupport.infoMetadata(name, help);
-    }
-
     @Override
     public InfoSnapshot build() {
       return new InfoSnapshot(buildMetadata(), dataPoints);

prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java

@@ -55,9 +55,9 @@ private static <T extends DataPointSnapshot> void validateLabels(
 
   public abstract static class Builder<T extends Builder<T>> {
 
-    @Nullable protected String name;
-    @Nullable protected String help;
-    @Nullable protected Unit unit;
+    @Nullable private String name;
+    @Nullable private String help;
+    @Nullable private Unit unit;
 
     /**
      * The name is required. If the name is missing or invalid, {@code build()} will throw an {@link
@@ -85,7 +85,7 @@ protected MetricMetadata buildMetadata() {
       if (name == null) {
         throw new IllegalArgumentException("Missing required field: name is null");
       }
-      return MetricMetadataSupport.metricMetadata(name, help, unit);
+      return new MetricMetadata(name, help, unit);
     }
 
     protected abstract T self();

prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/CounterSnapshotTest.java

@@ -94,18 +94,14 @@ void testEmptyCounter() {
   @Test
   void testTotalSuffixPresent() {
     CounterSnapshot snapshot = CounterSnapshot.builder().name("test_total").build();
-    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("test");
-    SnapshotTestUtil.assertDerivedMetadata(snapshot, "test", "test_total", "test_total");
+    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("test_total");
+    SnapshotTestUtil.assertDerivedMetadata(snapshot, "test_total", "test_total", "test_total");
   }
 
   @Test
-  void testCounterUnitDerivedFromTypedBuilder() {
-    CounterSnapshot snapshot =
-        CounterSnapshot.builder().name("test_total").unit(Unit.SECONDS).build();
-
-    SnapshotTestUtil.assertMetadata(snapshot, "test_seconds", null, "seconds");
-    SnapshotTestUtil.assertDerivedMetadata(
-        snapshot, "test_seconds", "test_total_seconds", "test_total");
+  void testCounterBuilderKeepsLegacyUnitValidation() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> CounterSnapshot.builder().name("test_total").unit(Unit.SECONDS).build());
   }
 
   @Test

prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/InfoSnapshotTest.java

@@ -62,14 +62,14 @@ void testDataImmutable() {
   @Test
   void testNameMayIncludeSuffix() {
     InfoSnapshot snapshot = InfoSnapshot.builder().name("jvm_info").build();
-    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("jvm");
-    SnapshotTestUtil.assertDerivedMetadata(snapshot, "jvm", "jvm_info", "jvm_info");
+    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("jvm_info");
+    SnapshotTestUtil.assertDerivedMetadata(snapshot, "jvm_info", "jvm_info", "jvm_info");
   }
 
   @Test
   void testNameMayIncludeSuffixDot() {
     InfoSnapshot snapshot = InfoSnapshot.builder().name("jvm.info").build();
-    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("jvm");
-    SnapshotTestUtil.assertDerivedMetadata(snapshot, "jvm", "jvm.info", "jvm.info");
+    assertThat(snapshot.getMetadata().getPrometheusName()).isEqualTo("jvm_info");
+    SnapshotTestUtil.assertDerivedMetadata(snapshot, "jvm.info", "jvm.info", "jvm.info");
   }
 }