fix escaping

Signed-off-by: Gregor Zeitlinger <[email protected]>

Author: zeitlinger

prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java

@@ -2785,10 +2785,10 @@ public void testLabelValueEscape() throws IOException {
 
   @ParameterizedTest
   @CsvSource({
-    "'application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited', 'application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited; escaping=values'",
-    "'text/plain;version=0.0.4', 'text/plain; version=0.0.4; charset=utf-8; escaping=values'",
+    "'application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited', 'application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited; escaping=underscores'",
+    "'text/plain;version=0.0.4', 'text/plain; version=0.0.4; charset=utf-8; escaping=underscores'",
     "'application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited; escaping=allow-utf-8', 'application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited; escaping=allow-utf-8'",
-    "'application/openmetrics-text', 'application/openmetrics-text; version=1.0.0; charset=utf-8; escaping=values'",
+    "'application/openmetrics-text', 'application/openmetrics-text; version=1.0.0; charset=utf-8; escaping=underscores'",
     "'application/openmetrics-text;version=0.0.1; escaping=underscores', 'application/openmetrics-text; version=1.0.0; charset=utf-8; escaping=underscores'",
     "'text/plain;version=0.0.4; escaping=allow-utf-8', 'text/plain; version=0.0.4; charset=utf-8; escaping=allow-utf-8'"
   })

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

@@ -63,15 +63,15 @@ public MetricMetadata(String name, String help, Unit unit) {
    * The name does not include the {@code _total} suffix for counter metrics or the {@code _info}
    * suffix for Info metrics.
    *
-   * <p>The name may contain dots. Use {@link #getPrometheusName()} to get the name in Prometheus
-   * format, i.e. with dots replaced by underscores.
+   * <p>The name may contain any Unicode chars. Use {@link #getPrometheusName()} to get the name in
+   * legacy Prometheus format, i.e. with all dots and all invalid chars replaced by underscores.
    */
   public String getName() {
     return name;
   }
 
   /**
-   * Same as {@link #getName()} but with all invalid characters replaced by underscores.
+   * Same as {@link #getName()} but with all invalid characters and dots replaced by underscores.
    *
    * <p>This is used by Prometheus exposition formats.
    */

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

@@ -576,7 +576,11 @@ private static MetricSnapshot createEscapedMetricSnapshot(
    * which by definition is a noop). This method does not do any validation of the name.
    */
   public static String escapeName(String name, EscapingScheme scheme) {
-    if (name.isEmpty() || isValidLegacyMetricName(name)) {
+    boolean noEscapeNeeded =
+        isValidLegacyMetricName(name)
+            && !(scheme == EscapingScheme.DOTS_ESCAPING
+                && (name.contains(".") || name.contains("_")));
+    if (name.isEmpty() || noEscapeNeeded) {
       return name;
     }
 

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

@@ -379,7 +379,7 @@ public void testEscapeMetricSnapshotGaugeEscapingNeeded() {
         "some_label",
         "label??value",
         "unicode_dot_and_dot_dots_dot_____",
-        "some_label",
+        "some__label",
         "label??value",
         EscapingScheme.DOTS_ESCAPING,
         GaugeSnapshot.class);