prometheus: Remove unit suffix for unit 1

CHANGELOG.md

@@ -8,6 +8,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+- The `go.opentelemetry.io/otel/exporters/prometheus` exporter do not add `_ratio` suffix for unit "1" anymore when unit suffix feature is enabled. (#4131)
+
 ## [1.16.0/0.39.0] 2023-05-18
 
 This release contains the first stable release of the OpenTelemetry Go [metric API].

exporters/prometheus/exporter.go

@@ -313,7 +313,6 @@ func sanitizeRune(r rune) rune {
 }
 
 var unitSuffixes = map[string]string{
-	"1":  "_ratio",
 	"By": "_bytes",
 	"ms": "_milliseconds",
 }

exporters/prometheus/testdata/gauge.txt

@@ -1,6 +1,6 @@
-# HELP bar_ratio a fun little gauge
-# TYPE bar_ratio gauge
-bar_ratio{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} .75
+# HELP bar a fun little gauge
+# TYPE bar gauge
+bar{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} .75
 # HELP otel_scope_info Instrumentation Scope metadata
 # TYPE otel_scope_info gauge
 otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1

exporters/prometheus/testdata/without_scope_info.txt

@@ -1,6 +1,6 @@
-# HELP bar_ratio a fun little gauge
-# TYPE bar_ratio gauge
-bar_ratio{A="B",C="D"} 1
+# HELP bar a fun little gauge
+# TYPE bar gauge
+bar{A="B",C="D"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1