Fix asserttracematch Test Failures

Update failing pure-stage simulation tests so assert_trace_match() passes again.

Workflow

1. Identify the failing test

The user will name a test function, file, or stage. Locate it under crates/amaru-consensus/src/stages/<stage>/tests.rs (or amaru-pure-stage tests). Read the stage's test_setup.rs for register_guards(), setup(), and any existing te_* / tm_* helpers.

2. Run the test and capture the diff

cargo test <test_name> -p amaru-consensus -- --nocapture

Or for pure-stage tests:

cargo test <test_name> -p amaru-pure-stage -- --nocapture

On trace mismatch, pretty_assertions::assert_eq! prints a diff between left (actual trace) and right (expected TraceMatch list). Read both sides carefully before editing.

3. Diagnose the failure type

A. Trace content mismatch — actual entries differ from expected. Update the assert_trace_match call.

B. Generic/untyped representation — actual shows typetag with Map/array structure instead of a typed Rust value. A deserializer is missing from register_guards() in the stage's test_setup.rs:

• External effects → amaru_pure_stage::register_effect_deserializer::<T>().boxed()
• Messages, state, tuples, and other SendData → amaru_pure_stage::register_data_deserializer::<T>().boxed()

Re-run the test after adding guards; the trace should show properly typed values.

C. No assertion or broken assertion — test has no assert_trace_match, or the expected list is too wrong to patch incrementally. Replace the expected slice with &[] temporarily, run the test, and use the full actual trace printed on the left side as the starting point.

4. Translate actual trace entries to TraceMatch values

Use tm_* constructors from amaru_pure_stage::trace_match (re-exported via test_utils.rs):

Trace entry kind	Exact match	Property match (preferred when possible)
State	tm_state(stage, &state)	tm_state_match(stage, |s| ...)
Input	tm_input(stage, &msg)	—
Send	tm_send(from, to, msg)	tm_send_match(from, to, |m| ...), tm_send_type::<T>(from, to)
Terminate	tm_terminate(stage)	—
Terminated	tm_terminated(stage, reason)	—
AddStage	tm_add_stage(at, name)	—
WireStage	tm_wire_stage(parent, child)	tm_wire_stage_state, tm_wire_stage_state_supervised

Matching strategy:

• Prefer property matchers (tm_state_match, tm_send_match) when only part of a value matters (e.g. a single field changed, dynamic stage suffixes, random peer IDs).
• Use exact matchers (tm_state, tm_send, tm_input) when the full value is stable and intentional.
• For external effects with variable payloads, use or create a property matcher (see tm_record_metrics in validate_block/test_setup.rs as a pattern).

Existing te_* helpers in test_utils.rs or per-stage test_setup.rs build TraceEntry values. Any TraceEntry converts to TraceMatch via From, so te_load_header(...) etc. still work inside assert_trace_match lists.

5. Create new helpers when needed

When a trace entry type has no suitable tm_* helper:

• Generic, reusable → add to crates/amaru-pure-stage/src/trace_match.rs
• Consensus-specific (particular effect types, stage naming conventions) → add to crates/amaru-consensus/src/stages/test_utils.rs or the stage's test_setup.rs

Follow existing patterns:

• tm_record_metrics — property match on Effect::External with cast_ref
• tm_state_match / tm_send_match in trace_match.rs — typed cast_ref + predicate + human-readable description string

6. Verify

Re-run the failing test until it passes. Then run the stage's full test module to catch regressions:

cargo test -p amaru-consensus --test tests stages::<stage>::tests

Or the relevant test file filter. Ensure cargo clippy-amaru is clean if you added new helpers.

Key files

• crates/amaru-pure-stage/src/trace_match.rs — assert_trace_match, all tm_* helpers
• crates/amaru-consensus/src/stages/test_utils.rs — run_simulation, assert_trace, shared te_* / tm_*
• crates/amaru-consensus/src/stages/<stage>/test_setup.rs — register_guards(), stage-specific te_* / tm_*
• crates/amaru-consensus/src/stages/<stage>/tests.rs — test bodies with assertions

Common pitfalls

• Resume entries are filtered out by assert_trace_match; do not include them in expected lists.
• Stage names in traces may include random suffixes (e.g. tp-1/child-abc). Use contains matchers (tm_send, tm_wire_stage) or property predicates rather than exact names when appropriate.
• register_guards() return value must be held for the test lifetime (typically _guards or guards in setup()).
• When migrating from assert_trace to assert_trace_match, replace te_* literals with tm_* equivalents only where exact matching is too brittle.