fix: Coerce aggregation_temporality to symbol

The OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE env var sets the
temporality as a string. However, checks throughout the metrics SDK and
the OTLP exporter expect the temporality to be a symbol.

Now, when aggregations that use this env var are initialized, the
temporality will be coerced into a symbol.

metrics_sdk/lib/opentelemetry/sdk/metrics/aggregation/explicit_bucket_histogram.rb

@@ -26,7 +26,7 @@ def initialize(
  record_min_max: true
  )
  @data_points = {}
- @aggregation_temporality = aggregation_temporality
+ @aggregation_temporality = aggregation_temporality.to_sym
  @boundaries = boundaries && !boundaries.empty? ? boundaries.sort : nil
  @record_min_max = record_min_max
  end

metrics_sdk/lib/opentelemetry/sdk/metrics/aggregation/sum.rb

@@ -15,7 +15,7 @@ class Sum
 
  def initialize(aggregation_temporality: ENV.fetch('OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE', :delta))
  # TODO: the default should be :cumulative, see issue #1555
- @aggregation_temporality = aggregation_temporality
+ @aggregation_temporality = aggregation_temporality.to_sym
  @data_points = {}
  end
 

metrics_sdk/test/opentelemetry/sdk/metrics/aggregation/explicit_bucket_histogram_test.rb

@@ -21,6 +21,27 @@
  let(:start_time) { (Time.now.to_r * 1_000_000_000).to_i }
  let(:end_time) { ((Time.now + 60).to_r * 1_000_000_000).to_i }
 
+ describe '#initialize' do
+ it 'defaults to the delta aggregation temporality' do
+ exp = OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :delta
+ end
+
+ it 'sets parameters from the environment and converts them to symbols' do
+ exp = OpenTelemetry::TestHelpers.with_env('OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE' => 'potato') do
+ OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new
+ end
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :potato
+ end
+
+ it 'prefers explicit parameters rather than the environment and converts them to symbols' do
+ exp = OpenTelemetry::TestHelpers.with_env('OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE' => 'potato') do
+ OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new(aggregation_temporality: 'pickles')
+ end
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :pickles
+ end
+ end
+
  describe '#collect' do
  it 'returns all the data points' do
  ebh.update(0, {})

metrics_sdk/test/opentelemetry/sdk/metrics/aggregation/sum_test.rb

@@ -14,6 +14,27 @@
  let(:start_time) { (Time.now.to_r * 1_000_000_000).to_i }
  let(:end_time) { ((Time.now + 60).to_r * 1_000_000_000).to_i }
 
+ describe '#initialize' do
+ it 'defaults to the delta aggregation temporality' do
+ exp = OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :delta
+ end
+
+ it 'sets parameters from the environment and converts them to symbols' do
+ exp = OpenTelemetry::TestHelpers.with_env('OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE' => 'potato') do
+ OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new
+ end
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :potato
+ end
+
+ it 'prefers explicit parameters rather than the environment and converts them to symbols' do
+ exp = OpenTelemetry::TestHelpers.with_env('OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE' => 'potato') do
+ OpenTelemetry::SDK::Metrics::Aggregation::ExplicitBucketHistogram.new(aggregation_temporality: 'pickles')
+ end
+ _(exp.instance_variable_get(:@aggregation_temporality)).must_equal :pickles
+ end
+ end
+
  it 'sets the timestamps' do
  sum_aggregation.update(0, {})
  ndp = sum_aggregation.collect(start_time, end_time)[0]