agent-framework/dotnet/docs/workflows/wf-coverage-summary.md

Workflows Unit Test Coverage — Snapshot

This document captures a coverage snapshot of Microsoft.Agents.AI.Workflows produced by running the existing Microsoft.Agents.AI.Workflows.UnitTests suite. It is the input for wf-coverage-plan.md, which proposes incremental work to lift coverage to the 85%/90% targets.

How this snapshot was produced

cd dotnet
dotnet build tests/Microsoft.Agents.AI.Workflows.UnitTests/Microsoft.Agents.AI.Workflows.UnitTests.csproj -f net10.0

dotnet test --project tests/Microsoft.Agents.AI.Workflows.UnitTests/Microsoft.Agents.AI.Workflows.UnitTests.csproj \
  -f net10.0 --no-build \
  --coverage --coverage-output-format cobertura \
  --coverage-output coverage.cobertura.xml \
  --coverage-settings tests/coverage.runsettings

reportgenerator \
  -reports:tests/Microsoft.Agents.AI.Workflows.UnitTests/bin/Debug/net10.0/TestResults/coverage.cobertura.xml \
  -targetdir:./coverage-report \
  -reporttypes:'Html_Dark;JsonSummary;TextSummary' \
  -assemblyfilters:'+Microsoft.Agents.AI.Workflows;-Microsoft.Agents.AI.Workflows.Declarative*'

• Tooling: dotnet test with Microsoft.Testing.Extensions.CodeCoverage (the same configuration documented in dotnet/.github/skills/build-and-test/SKILL.md).
• Scope: only the Microsoft.Agents.AI.Workflows assembly. The Microsoft.Agents.AI.Workflows.Declarative* family is excluded — those have their own test projects and a different ownership area.
• Test result: 460 passed, 22 skipped, 0 failed (482 total). The 22 skipped tests are the previously-flaky ObservabilityTests and WorkflowRunActivityStopTests; PR #5837 re-enables them all.

Headline numbers

Metric	Value	Target
Line coverage	79.7% (4386 / 5499)	85% / 90%
Branch coverage	67.2% (1111 / 1653)	—
Method coverage	80.9% (903 / 1115)	—
Fully-covered methods	70.8% (790 / 1115)	—
Coverable lines	5,499	—
Uncovered lines	1,113	—
Classes	237 (185 source files)	—

Distance to the 85% line target ≈ +292 covered lines. Distance to the 90% personal target ≈ +567 covered lines.

The much larger branch-coverage gap (67.2%) is the bigger structural problem: many code paths are reached but not all branches inside them are exercised.

In-flight PRs that already address part of this gap

The plan in wf-coverage-plan.md excludes the classes covered by these PRs to avoid duplicate work or merge conflicts:

PR	Classes added/improved
#5824 — RouteBuilder unit tests	RouteBuilder (143 lines, 58 currently uncovered)
#5826 — WorkflowBuilder specialized edge tests	WorkflowBuilderExtensions (51 lines, 21 uncov), SwitchBuilder (already 90.4%, but null-guard branches added)
#5833 — Magentic E2E coverage	MagenticWorkflowBuilder (69 lines, 0%), MagenticOrchestrator (52%), MagenticTaskContext (35%), and the related Magentic event types (all 0%)
#5837 — Re-enable ObservabilityTests/WorkflowRunActivityStopTests	Observability/WorkflowTelemetryContext (42.7%), Observability/ActivityExtensions (0%), Observability/EdgeRunnerDeliveryStatusExtensions (0%), OpenTelemetryWorkflowBuilderExtensions (0%), and the bulk of Tags / EventNames / ActivityNames

Estimated combined impact once all four merge: ~360–410 of the current 1,113 uncovered lines become covered, lifting line coverage to roughly 86–87% even before any of the new work proposed in the plan.

Top uncovered classes (after excluding in-flight PRs)

Sorted by uncovered line count. "Public surface" indicates whether the class itself or its uncovered members are part of the public API of the Microsoft.Agents.AI.Workflows assembly — those are the highest-leverage targets.

#	Class	Public surface	Line cov	Branch cov	Coverable	Uncov
1	WorkflowSession	internal (reached via WorkflowHostAgent)	67.7%	47.5%	217	70
2	WorkflowBuilder	public	82.4%	79.4%	273	48
3	Workflow	public	44.4%	44.1%	63	35
4	ExecutorBindingExtensions	public	32.0%	n/a	50	34
5	Execution.EdgeConnection	public	36.1%	37.5%	47	30
6	HandoffWorkflowBuilderCore<TBuilder>	public (base)	80.7%	65.7%	114	22
7	Checkpointing.FileSystemJsonCheckpointStore	public	62.2%	57.1%	53	20
8	InProc.InProcStepTracer	internal	62.9%	21.4%	54	20
9	Visualization.WorkflowVisualizer	public	92.1%	93.5%	230	18
10	EdgeId	public struct	37.5%	0.0%	24	15
11	Execution.ExecutorIdentity	internal	28.5%	18.7%	21	15
12	Checkpointing.ExecutorIdentityConverter	internal	12.5%	0.0%	16	14
13	Checkpointing.JsonWireSerializedValue	internal	48.1%	50.0%	27	14
14	Checkpointing.PortableValueConverter	internal	57.5%	35.7%	33	14
15	Execution.StateScope	internal	79.0%	72.2%	62	13
16	MessageMerger	internal	89.6%	85.7%	126	13
17	Specialized.RequestPortExtensions	internal	7.1%	0.0%	14	13
18	WorkflowEvaluationExtensions	public	89.4%	75.0%	114	12
19	ExecutorBinding	internal (base)	60.7%	28.5%	28	11
20	Checkpointing.WorkflowInfo	internal	80.3%	54.5%	51	10
21	WorkflowHostAgent	public	70.5%	75.0%	34	10
22	StatefulExecutor<TState, TInput, TOutput>	public	0.0%	n/a	9	9
23	CheckpointableRunBase	internal (base of Run)	42.8%	16.6%	14	8
24	Reflection.MessageHandlerInfo	internal	78.3%	66.6%	37	8
25	Specialized.ConcurrentEndExecutor	internal	78.9%	n/a	38	8

Other notable gaps

• 0% on small-but-public types: JsonCheckpointStore (abstract base, 1 line, no test instantiates it), IResettableExecutor (interface default method, 3 lines), MagenticPlanReviewRequest/MagenticPlanReviewResponse (5/2 lines — partly covered by #5833).
• Obsolete attributes with 0% coverage but no value to test: YieldsMessageAttribute, StreamsMessageAttribute. Both are explicitly marked [Obsolete] and are ignored by both the source generator and the runtime — excluded from the plan.
• Records / events with low line counts (SubworkflowWarningEvent, RequestHaltEvent, ResetChatSignal, MagenticReplannedEvent, etc.) appear as 0% only because no test ever constructs them. Tiny absolute impact individually, but easy bulk wins via constructor smoke tests.
• Observability.* classes appear at 0–43% because the entire ObservabilityTests and WorkflowRunActivityStopTests files are skipped on main. Re-enabling them via PR #5837 is expected to lift those into the 80–95% range without any new test code.

Per-area coverage breakdown

(Aggregated by namespace; Microsoft.Agents.AI.Workflows.Declarative* excluded.)

Area	Approx line cov	Notes
Top-level (Workflow, WorkflowBuilder, WorkflowSession, WorkflowHostAgent, Run, StreamingRun)	~75%	Largest absolute gap; many public-surface gaps.
Execution.*	~85–90% on hot-path types, <40% on EdgeConnection and ExecutorIdentity	Identity/equality and connection-validation paths under-tested.
Checkpointing.*	~80% mean	Several converter classes 12–58%; FileSystemJsonCheckpointStore 62% (concurrency / corruption / index-rebuild paths).
InProc.*	~85%	InProcStepTracer is the only outlier (62.9% line, 21.4% branch).
Reflection.*	~85%	Solid; minor gaps.
Visualization.*	92.1%	Already strong; remaining 18 lines are escape-handling and a couple of unusual edge layouts.
Observability.*	<45% today, expected >85% after #5837.
Specialized.Magentic.*	35–82% today; the orchestrator + builder + task context lift to high coverage after #5833.
Specialized.* (non-Magentic — handoff, group-chat, request-port helpers)	~80–90%	RequestPortExtensions (7.1%) is the only sharp outlier.
Evaluation.*	89.4%	Mostly there; only branch coverage gaps remain.

Reproducing the per-class data

The full per-class table used to build the buckets above is regenerated by:

python3 - <<'PY'
import json
data = json.load(open('coverage-report/Summary.json'))
asm = data['coverage']['assemblies'][0]
def uncov(c): return c['coverablelines'] - c['coveredlines']
for c in sorted(asm['classesinassembly'], key=lambda c: -uncov(c)):
    if uncov(c) == 0: continue
    print(f"{c['name']:80s}  {c['coverage']:5.1f}%  uncov={uncov(c):4d}  lines={c['coverablelines']}")
PY