feat: Improve pdata::otap::testing module and expose it to other crates

rust/otap-dataflow/crates/pdata/Cargo.toml

@@ -47,11 +47,14 @@ workspace = true
 
 [features]
 bench = []
+testing = []
 
 [[bench]]
 name = "concatenate"
 harness = false
+required-features = ["testing"]
 
 [[bench]]
 name = "sort_by_parent_then_id"
 harness = false
+required-features = ["testing"]

rust/otap-dataflow/crates/pdata/src/error.rs

@@ -241,7 +241,7 @@ pub enum Error {
 
     #[error(
         "Column `{name}` type mismatch in payload {payload_type:?}, \
-         expected OTAP type {expected:?}, actual: {actual}"
+        expected OTAP type {expected:?}, actual: {actual}"
     )]
     FieldTypeMismatch {
         name: String,

rust/otap-dataflow/crates/pdata/src/lib.rs

@@ -27,7 +27,7 @@ pub use otlp::OtlpProtoBytes;
 pub use payload::{OtapPayload, OtapPayloadHelpers};
 
 /// Testing support
-// #[cfg(test)] ?
+#[cfg(any(test, feature = "testing"))]
 pub mod testing;
 
 // The validation module is only used for integration tests with the OpenTelemetry Collector.

rust/otap-dataflow/crates/pdata/src/otap.rs

@@ -30,6 +30,10 @@ pub mod schema;
 #[allow(missing_docs)]
 pub mod transform;
 
+/// Testing utilities for constructing OTAP batches in tests.
+#[cfg(any(test, feature = "testing"))]
+pub mod testing;
+
 /// The OtapBatch enum is used to represent a batch of OTAP data.
 #[derive(Clone, Debug, PartialEq)]
 #[allow(clippy::large_enum_variant)]
@@ -180,7 +184,7 @@ impl From<Traces> for OtapArrowRecords {
 /// storing and retrieving Arrow record batches in a type-safe manner. It is
 /// implemented by various structs that represent each signal type and provides
 /// methods to efficiently set and get record batches.
-pub trait OtapBatchStore: Default + Clone {
+pub trait OtapBatchStore: Default + Clone + Into<OtapArrowRecords> {
     /// Internally, implementers should use a bitmask for the types they support.
     /// The offsets in the bitmask should correspond to the ArrowPayloadType enum values.
     const TYPE_MASK: u64;