Provides the prove-don't-assume recipes for moq.analyzers โ load BEFORE asserting any claim you have not observed: "Moq has this overload", "this snippet triggers/doesn't trigger MoqXXXX", "this KnownSymbols entry resolves", "the span lands here", "Roslyn behaves like X", "my change is perf-neutral", "the DLL loads in VS", "nothing else regressed". Each recipe is when-to-use / steps / expected output / pitfalls, with a worked example from this repo's history (phantom IReturns symbols, GeneratedReturnsExtensions #1243, ConstructorBody vs MethodBody #1253, void-Setup false negative #1270). Triggers: verifying an API exists, validating proposed test expectations, empirical Roslyn probes, CS8032 checks, pre-merge regression proof. NOT for: the measurement tools' own mechanics and output interpretation (moq-analyzers-diagnostics-and-tooling), corpus/statistics research design (moq-analyzers-research-methodology), or test-suite authoring patterns (moq-analyzers-validation-and-qa).
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Provides the prove-don't-assume recipes for moq.analyzers โ load BEFORE asserting any claim you have not observed: "Moq has this overload", "this snippet triggers/doesn't trigger MoqXXXX", "this KnownSymbols entry resolves", "the span lands here", "Roslyn behaves like X", "my change is perf-neutral", "the DLL loads in VS", "nothing else regressed". Each recipe is when-to-use / steps / expected output / pitfalls, with a worked example from this repo's history (phantom IReturns symbols, GeneratedReturnsExtensions #1243, ConstructorBody vs MethodBody #1253, void-Setup false negative #1270). Triggers: verifying an API exists, validating proposed test expectations, empirical Roslyn probes, CS8032 checks, pre-merge regression proof. NOT for: the measurement tools' own mechanics and output interpretation (moq-analyzers-diagnostics-and-tooling), corpus/statistics research design (moq-analyzers-research-methodology), or test-suite authoring patterns (moq-analyzers-validation-and-qa).
Proof toolkit: recipes that catch plausible-but-wrong
This project ships Roslyn analyzers (compiler plugins that inspect code and report
diagnostics) into mission-critical codebases. Its costliest historical failures were
changes that looked correct but were wrong โ code and tests written from memory of
what Moq or Roslyn "obviously" does. Every recipe below exists because assuming that
thing once produced a real bug. The rule:
A claim you have not observed is a hypothesis. Run the probe, paste the output,
THEN write the code.
All commands are repo-root relative. In sandboxes: export PATH="$HOME/.dotnet:$HOME/.dotnet/tools:$PATH".
Verified 2026-07-02 against commit 05135b2.
Recipe index
#
You are about to claim...
Recipe
1
"Moq has/lacks this type, member, or overload"
dotnet-inspect + NuGet-cache reflection
2
"This code does / does not trigger MoqXXXX"
Run the BUILT DLLs on a snippet
3
"This KnownSymbols entry resolves in real compilations"
Resolves-non-null test pair
4
"The diagnostic span lands on this token"
Markup pin + observed span + STOP protocol
5
"Roslyn API X behaves like Y"
Scratch probe pinned to Roslyn 4.8
6
"My change is performance-neutral / faster"
Hypothesis-first BDN + PerfDiff
7
"The shipped DLL loads in every supported host"
Referenced-assembly check + load-test matrix
8
"My fix regresses nothing else"
Full-matrix run + span-pin inviolability
Recipe 1 โ Prove a Moq API exists or has an overload
When to use: before adding a MoqKnownSymbols entry (src/Common/WellKnown/MoqKnownSymbols.cs),
before writing analyzer logic that assumes an overload shape, before asserting "Moq
version X supports Y". Moq's fluent surface is large, version-dependent, and full of
near-misses โ memory is not evidence.
Steps:
Primary instrument โ dotnet-inspect (a CLI that dumps a NuGet package's API
surface; dotnet tool install -g dotnet-inspect if missing). ALWAYS pin the version
to one of the two the test matrix covers:
dotnet-inspect member "IReturns<TMock, TResult>" --package Moq@4.18.4 --all
dotnet-inspect member "IReturns<TMock, TResult>" --package Moq@4.8.2 --all
--all is required for interface members. Observed 2026-07-02: Returns has
20 overloads in 4.18.4 vs 19 in 4.8.2 (the Returns(InvocationFunc) overload is
the 4.18.4-only addition; the Returns(Delegate) catch-all exists in both
versions) โ exactly the kind of gap that matters when a rule must behave on both
versions.
When the question is about an EXACT metadata name (arity, non-generic vs generic,
nested types), fall back to reflection over the cached package DLL. This probe was
run verbatim on 2026-07-02:
mkdir -p /tmp/moq-probe && cd /tmp/moq-probe
cat > probe.csproj <<'EOF'
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup><OutputType>Exe</OutputType><TargetFramework>net8.0</TargetFramework></PropertyGroup>
</Project>
EOF
cat > Program.cs <<'EOF'
using System;
using System.Reflection;
Assembly asm = Assembly.LoadFrom(args[0]);
foreach (string name in args[1..])
Console.WriteLine($"{name} => {(asm.GetType(name, throwOnError: false) is null ? "NOT FOUND" : "exists")}");
EOF
dotnet run --project . -- ~/.nuget/packages/moq/4.18.4/lib/net6.0/Moq.dll \
'Moq.Language.IReturns''Moq.Language.IReturns`1''Moq.Language.IReturns`2''Moq.GeneratedReturnsExtensions'
If the package is not in ~/.nuget/packages/moq/<version>/lib/..., restore it first
(any project referencing it, or dotnet add package). 4.8.2's newest lib folder is
netstandard1.3; 4.18.4's is net6.0 (both load fine for metadata queries).
Expected output (observed 2026-07-02, both 4.8.2 and 4.18.4):
Moq.Language.IReturns => NOT FOUND
Moq.Language.IReturns`1 => NOT FOUND
Moq.Language.IReturns`2 => exists
Moq.GeneratedReturnsExtensions => exists
Pitfalls:
Pitfall
Consequence
dotnet-inspect fuzzy-matches names: querying member "IReturns" or "IReturns<T>" silently returns the arity-2 interface (observed 2026-07-02)
You "confirm" that a phantom type exists. dotnet-inspect CANNOT prove absence of an exact metadata name โ use the reflection fallback for existence-at-exact-name questions
Omitting @version queries LATEST Moq on nuget.org, not what this repo tests against
Overload counts and members drift; always pin @4.8.2 / @4.18.4
Checking only one Moq version
The test matrix runs both; an API present only in 4.18.4 needs a version-gated test row
Worked example (the phantom symbols and issue #1243):MoqKnownSymbols exposes
IReturns and IReturns1 properties (lines 293/298) whose metadata names
Moq.Language.IReturns / Moq.Language.IReturns1do not exist in ANY Moq version โ they resolvenullforever, and everyIsKnownReturnValueMethodNamearm consulting them is dead weight. Meanwhile the delegate-basedReturnsAsyncoverloads that Moq1203's string-name fallback was invented to cover actually live inMoq.GeneratedReturnsExtensionsโ a real class, present in BOTH 4.8.2 and 4.18.4, thatMoqKnownSymbols` never tracked. Ten minutes with the probes above replaces a
name-based fallback (an ADR-001 violation producing false negatives) with a proper
symbol registration. That is issue #1243 (open, 2026-07-02) end to end: the fallback
existed only because nobody proved where the overloads lived.
Recipe 2 โ Prove analyzer behavior empirically
When to use: before writing {|MoqXXXX:...|} expectations for a new test, before
claiming "this is a false positive/negative", before filing or fixing an issue based on
what an analyzer "should" report. The authority is the BUILT DLL, not the source you
just read.
Steps:
Write the scenario as a self-contained .cs file (own using Moq;, own fixture types).
Run the live-DLL harness (full mechanics, knobs, and limitations in
moq-analyzers-diagnostics-and-tooling ยง1):
dotnet build src/Analyzers/Moq.Analyzers.csproj # only if you changed analyzer code
.github/skills/moq-analyzers-diagnostics-and-tooling/scripts/run-analyzer-on-snippet.sh mysnippet.cs
Compare observed diagnostics (ID + line + column) against your expectation. Only
then encode the expectation as markup in the test suite.
Expected output: one line per diagnostic, file(line,col): warning MoqXXXX: message;
(none) for a clean snippet; exit 2 + CS errors if the snippet doesn't compile
(distinguish "no diagnostics" from "didn't compile" โ a snippet that doesn't compile
proves nothing).
Worked example (issue #1270's validation discipline, reproduced 2026-07-02): the
audit's test-coverage issue #1270 states "Every expected diagnostic below was verified
by running the current analyzers against the exact test code" โ and that validation is
what caught a live false negative. Probe snippet:
var mock = new Mock<Worker>(); // Worker: non-virtual DoVoid() and GetValue()
mock.Setup(x => x.DoVoid()); // binds NON-generic Setup(Expression<Action<T>>)
mock.Setup(x => x.GetValue()); // binds generic Setup<TResult>(...)
Observed harness output: Moq1200 fires for GetValue() only. The DoVoid() setup โ
equally broken at runtime โ is silent, because IsMoqSetupMethod
(src/Common/ISymbolExtensions.Moq.cs:42) requires
symbol is IMethodSymbol { IsGenericMethod: true }, and void-member setups bind the
non-generic overload. Every setup of a void member is invisible to Setup-family rules
today. Because the expectations were validated empirically, #1270 pins this as
commented known-FN rows instead of shipping rows that assert a diagnostic the analyzer
never produces (which would have "passed" only after someone silently weakened them).
Pitfalls: harness severities are forced to warning (don't read severity off it);
harness compiles with the host SDK's Roslyn while the test suite pins Roslyn 4.8 โ
parse-level differences (C# 13 constructs) can differ; a harness result is evidence,
not a regression test โ every FP/FN fix still ships with an issue-linked test.
Recipe 3 โ Prove a symbol registration is live
When to use: whenever you add or touch a MoqKnownSymbols /
src/Common/WellKnown/ entry. A typo'd metadata name fails SILENTLY: the property
resolves null, CreateLazyMethods yields an empty array, IsInstanceOf returns
false, and the analyzer just... never fires. No error anywhere. (This is how the
phantom IReturns/IReturns1 properties survived โ Recipe 1.)
Steps: add the four-test pattern from
tests/Moq.Analyzers.Test/Common/MoqKnownSymbolsTests.ReturnsAndThrows.cs (the
partial-class family MoqKnownSymbolsTests.*.cs is the template):
plus the same pair for the method group (Assert.True(...IsEmpty) without Moq /
Assert.False(...IsEmpty) with Moq). Assert Name and Arity on the resolved type โ
IReturns2_WithMoqReference_ReturnsNamedTypeSymbol asserts Arity == 2, which is what
distinguishes the real interface from its phantom siblings.
Expected output: the WithMoq tests FAIL if the metadata name is wrong โ that is the
entire point. Run the slice:
dotnet test --settings ./build/targets/tests/test.runsettings \
--filter "FullyQualifiedName~MoqKnownSymbolsTests"
Pitfalls:
A Without-Moq null test alone proves nothing about liveness โ the phantom IReturns
properties pass their Without-Moq tests perfectly (2026-07-02: those are the only
tests they have; no with-Moq non-null pin exists for them because none can pass).
The with-Moq non-null assertion is the load-bearing one.
Prove the name with Recipe 1 first, in BOTH Moq versions, or document the version gate.
CreateLazyMethods accepts a null type and yields empty โ convenient, but it is
exactly the mechanism that makes dead registrations silent.
Recipe 4 โ Prove a diagnostic span
When to use: writing or changing any test markup, or any analyzer change that moves
where a diagnostic is reported. Spans in this project are character-precise and
non-negotiable: the diagnostic must land on the specific token users need highlighted
(the argument list for Moq1002, the variable identifier for Moq1500, the lambda
parameter for Moq1100 โ it varies by rule and is pinned by existing tests).
Steps:
Observe first: run the harness (Recipe 2) and read the (line,col) of the real
diagnostic. Example from the harness's own known-positive sample: Moq1002 reports at
column 33 โ the argument list (1, true) โ not at the new keyword.
Encode as markup: {|Moq1002:(1, true)|} asserts ID + exact span. The strongest
form, used when message arguments matter too
(tests/Moq.Analyzers.Test/NoMockOfLoggerAnalyzerTests.cs:27):
If a span test fails: read the test failure's expected-vs-actual span locations
carefully โ the framework reports both โ and treat the delta as information about
your syntax-tree navigation, not as a number to patch in the test.
The STOP protocol (repo law, .github/copilot-instructions.md:513 and
CONTRIBUTING.md:1198):
If a diagnostic span test fails even once, you MUST STOP work on
implementation. Re-evaluate your entire syntax tree navigation logic. If it fails a
second time, you must admit failure and request expert human guidance. Do not proceed.
Pitfalls: the classic plausible-but-wrong move is adjusting the markup to match
whatever the analyzer currently emits, converting a bug into a pinned expectation.
Direction of proof matters: decide the CORRECT span from the rule's user experience
(and existing sibling pins), then make the analyzer produce it. Never widen a span to a
whole invocation because it's easier to hit. Unmarked code in a test source is a
genuine negative assertion โ an unexpected diagnostic anywhere fails the test, so
moving a span silently breaks neighbors (Recipe 8).
Recipe 5 โ Prove a Roslyn API behavior when docs are ambiguous
When to use: any time analyzer logic depends on a Roslyn behavior you cannot quote
from the API docs with certainty โ operation-tree shapes, SymbolInfo candidate
semantics, syntax-token layouts, enum member availability in the pinned version. The
shipped analyzers compile against Microsoft.CodeAnalysis 4.8 (ADR-003,
Directory.Packages.props:21-22), so the probe must pin 4.8.0 too โ behavior and API
availability on your workstation's newer Roslyn prove nothing about the shipped floor.
Steps: scratch project OUTSIDE the repo tree (so Directory.Build.props/CPM don't
interfere), pinned package, print the fact. This exact probe was run 2026-07-02:
mkdir -p /tmp/roslyn-probe && cd /tmp/roslyn-probe
cat > probe.csproj <<'EOF'
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup><OutputType>Exe</OutputType><TargetFramework>net8.0</TargetFramework><Nullable>enable</Nullable></PropertyGroup>
<ItemGroup><PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" /></ItemGroup>
</Project>
EOF
cat > Program.cs <<'EOF'
using System;
using System.Linq;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Operations;
const string src = """
class C
{
public C() { var x = 1; } // constructor body
void M() { var y = 2; } // method body
}
""";
var tree = CSharpSyntaxTree.ParseText(src);
var compilation = CSharpCompilation.Create("probe", new[] { tree },
new[] { MetadataReference.CreateFromFile(typeof(object).Assembly.Location) });
var model = compilation.GetSemanticModel(tree);
foreach (var decl in tree.GetRoot().DescendantNodes().OfType<VariableDeclaratorSyntax>())
{
IOperation? root = model.GetOperation(decl);
while (root?.Parent is not null) root = root.Parent;
Console.WriteLine($"declarator '{decl.Identifier}': root operation kind = {root?.Kind}");
}
EOF
dotnet run --project .
Worked examples (settled โ do not re-probe, reuse the findings):
Issue #1253 (Moq1500):GetContainingMember walked ancestors looking for
OperationKind.MethodBody โ but constructor bodies root at
OperationKind.ConstructorBody, so the extremely common xUnit
constructor-creates-repository pattern was never analyzed. The issue's fix plan rests
on a probe-built table: method body โ MethodBody, constructor โ ConstructorBody,
property accessor โ MethodBody, local function โ outer MethodBody, field
initializer โ no declarator operation at all. One probe, five settled facts, and the
proof that the OperationKind.PropertyReference branch was dead code.
Issue #1262 (Moq1100):GetRefKind read only Modifiers[0]; the probe facts โ
(scoped ref int x) has Modifiers == [scoped, ref] while
GetDeclaredSymbol(param).RefKind == RefKind.Ref, and RefKind.RefReadOnlyParameter
EXISTS in Microsoft.CodeAnalysis 4.8.0 โ turned "iterate all modifiers" (the naive
fix) into "delete the syntax derivation, compare symbol RefKinds" (the correct one).
Probing settled both the bug and the fix shape.
Pitfalls: probing against the SDK's bundled Roslyn instead of the 4.8.0 package
(you'll conclude an API exists that the shipped floor lacks); forgetting that the test
suite ALSO compiles test sources with Roslyn 4.8 โ default LangVersion is C# 12 there,
so C# 13 syntax (params collections) is unparseable in-suite even though consumers'
newer hosts will feed it to your analyzer (that asymmetry is the root of the open
params-collection crash, issue #1241, 2026-07-02 โ whose fix is explicitly
scenario-untestable under the pinned test compiler and relies on a code-comment-
documented conservative guard instead).
Recipe 6 โ Prove a performance claim
When to use: before writing "this change is perf-neutral" or "this speeds up X" in
a PR. ADR-008 makes PerfDiff's exit code a required merge gate; per-keystroke cost is a
project priority.
Steps:
Hypothesis first, numbers second. Before running anything, write down what you
expect and why: which benchmark(s) should move, in which direction, roughly how much
("removing one GetSymbolInfo per invocation should move Moq1100's 1-file case a
few percent; everything else neutral"). A run you can't predict is a run you can't
interpret โ matching numbers confirm understanding; surprising numbers mean STOP and
explain before trusting either the change or the measurement. (Full experimental
discipline: moq-analyzers-research-methodology.)
Run the gate-equivalent comparison (BenchmarkDotNet benchmarks +
PerfDiff differ; mechanics, output paths, and strategy table in
moq-analyzers-diagnostics-and-tooling ยง2). Requires PowerShell 7 (pwsh) โ not
present in all sandboxes; run on a machine that has it or let CI's perf job run it:
./build/scripts/perf/CIPerf.sh -filter '*(FileCount: 1)'# PR fast path, same as CI
Paste the verdict AND the relevant -report-github.md table into the PR as evidence.
Expected output: PerfDiff exit 0 with per-strategy "No regressions detected"
logging, or exit 1 naming the strategy and benchmark. Thresholds and the per-strategy
defect table: moq-analyzers-diagnostics-and-tooling ยง2 (canonical); re-derive from
grep -rn 'Threshold' src/tools/PerfDiff/BDN/Regression/.
Pitfalls (all load-bearing, 2026-07-02): PerfDiff has open correctness defects
(#1265โ#1269): benchmarks missing from one side are silently dropped (a PR that breaks
the harness passes green โ confirm perfTest/results actually contains non-empty
*full-compressed.json); the absolute-budget strategies never consult the baseline (a
budget failure may not be YOUR regression โ check whether baseline already exceeded
it); infinite ratios are excluded from the verdict. A green perf gate is weaker
evidence than it looks; the hypothesis-first step is what catches what the gate misses.
Noise floor: benchmark reruns jitter โ a small "regression" on one run of a change that
touches nothing hot is more likely noise than signal; rerun before believing it.
Recipe 7 โ Prove host compatibility
When to use: any dependency bump or packaging change touching what ships in
analyzers/dotnet/cs. CS8032 is the compiler warning "An instance of analyzer ...
cannot be created" โ the analyzer DLL failed to LOAD in the consumer's compiler
process, so every rule silently vanishes for that consumer. Incident #850 shipped
exactly this (release v0.4.1 existed solely to fix it): the netstandard2.0 analyzer
referenced System.Collections.Immutable 9.x, which a .NET 8 host (VS 2022 17.8+)
cannot supply.
The claim to prove: every shipped DLL's referenced-assembly versions are โค what the
minimum host provides (System.Collections.Immutable โค 8.0.0.0,
System.Reflection.Metadata โค 8.0.0.0, Microsoft.CodeAnalysis == 4.8.0.0 per ADR-003).
Steps โ local referenced-assembly check (bash variant verified 2026-07-02; CI's
pwsh equivalent lives inline in .github/workflows/main.yml "Validate analyzer host
compatibility"):
mkdir -p /tmp/refcheck && cd /tmp/refcheck
cat > refcheck.csproj <<'EOF'
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup><OutputType>Exe</OutputType><TargetFramework>net8.0</TargetFramework></PropertyGroup>
</Project>
EOF
cat > Program.cs <<'EOF'
using System;
using System.Linq;
using System.Reflection;
foreach (string dll in args)
{
var asm = Assembly.Load(System.IO.File.ReadAllBytes(dll));
Console.WriteLine(System.IO.Path.GetFileName(dll));
foreach (var r in asm.GetReferencedAssemblies()
.Where(r => r.Name is "System.Collections.Immutable" or "System.Reflection.Metadata" or "Microsoft.CodeAnalysis"))
Console.WriteLine($" -> {r.Name} {r.Version}");
}
EOF
REPO=<repo-root>
dotnet run --project . -- \
$REPO/artifacts/bin/Moq.Analyzers/debug/Moq.Analyzers.dll \
$REPO/artifacts/bin/Moq.Analyzers/debug/Moq.CodeFixes.dll \
$REPO/artifacts/bin/Moq.Analyzers/debug/Microsoft.CodeAnalysis.AnalyzerUtilities.dll
Expected output (observed 2026-07-02):Microsoft.CodeAnalysis 4.8.0.0 and
System.Collections.Immutable 8.0.0.0 for the two Moq.* DLLs (AnalyzerUtilities shows
older 3.3/1.x refs โ lower is fine; HIGHER than 8.0.0.0 is the failure).
The triple enforcement (know it before trusting a green build):
Layer
Where
What it proves
ValidateAnalyzerHostCompatibility MSBuild target
build/targets/packaging/Packaging.targets:20
Resolved package versions โค max majors, at build/pack time
Inline CI DLL check
main.yml "Validate analyzer host compatibility"
The three shipped RELEASE DLLs' actual assembly references
analyzer-load-test CI job
main.yml (9-leg matrix, 2026-07-02: net8/9/10 dotnet-CLI on Linux ARM + net472/48/481 MSBuild on windows-2022 AND windows-2025-vs2026)
The packed nupkg actually loads โ build output grepped for CS8032 per leg
Pitfalls: a passing LOCAL build proves nothing โ your dev SDK is .NET 10 and
happily provides 9.x/10.x assemblies the VS 2022 host lacks; only the matrix proves
loading. Transitive bumps count: the #850 break came in through a dependency update,
not a direct reference (which is why Renovate ignores Microsoft.CodeAnalysis.* and
AnalyzerUtilities is capped โ ADR-004). Never "fix" CS8032 by bumping the Roslyn pin;
that trades old-host compatibility away silently (change-control territory).
Recipe 8 โ Prove a fix does not regress siblings
When to use: before declaring any analyzer/code-fix change done. The test suite is
a mesh of negative assertions: every UNMARKED line of every test source asserts "no
diagnostic here", AllAnalyzersVerifier
(tests/Moq.Analyzers.Test/Helpers/AllAnalyzersVerifier.cs) runs every discovered
analyzer over shared no-diagnostics suites, and TestDataExtensions fans each row
across 2 namespace styles ร up to 2 Moq versions. A change that makes YOUR rule fire in
one more place can fail tests belonging to three other rules โ that is the mesh
working.
Steps:
Full-matrix run, no filter (a --filter run proves only the slice you filtered):
dotnet build /p:PedanticMode=true# CI-parity: warnings are errors in CI, not locally
dotnet test --settings ./build/targets/tests/test.runsettings
Baseline 2026-07-02: 3,357 tests in Moq.Analyzers.Test + 4 in PerfDiff.Tests; in
sandboxes whose git remote is not a github.com URL, the 2 PackageTests.Baseline
snapshot tests fail for environment reasons (nuspec repository-URL scrubber) โ
anything ELSE failing is yours.
Read every failure through the span-pin lens: existing span pins are inviolable.
If your change moves a pinned span, the default conclusion is that your change is
wrong, not the pin. Recipe 4's STOP protocol applies to pre-existing tests with full
force โ repointing old markup to make a new feature pass is the single most
dangerous "fix" in this codebase.
For FP/FN fixes: prove the fix red-first โ run the new regression test against the
UNFIXED analyzer and paste the failure (issues #1253/#1262 both demand "confirmed
failing pre-fix" explicitly). A regression test that never failed proves nothing
about the bug.
If the change touches detection helpers in src/Common/, also run the
Doppelganger suites (--filter "FullyQualifiedName~Doppelganger" as a quick slice
before the full run) โ user-defined Mock<T> look-alikes must stay silent.
Expected output: zero failures beyond the documented sandbox-only PackageTests
pair, plus (for behavior changes) a pasted red-first failure. PR evidence requirements
(what to paste where) are moq-analyzers-change-control's territory.
Pitfalls: green-by-filter (the suite you didn't run is the one you broke);
.received.* Verify-snapshot files left in the tree after a failure (delete before
commit); "fixing" a sibling's now-failing negative row by marking it โ that converts
your regression into their pinned expectation. When a sibling rule's test fails and you
believe the NEW behavior is correct, that is a deliberate behavior change requiring its
own issue and review, not a test edit in passing.
The incidents behind these rules (Moq1203 saga, CS8032, S1135)
moq-analyzers-failure-archaeology
Severity/editorconfig configuration of shipped rules
moq-analyzers-config-and-flags
Rule docs / writing style
moq-analyzers-docs-and-writing
The FP-convergence campaign backlog (#1241โ#1278)
moq-analyzers-fp-convergence-campaign
Open research questions / beyond-SOTA goals
moq-analyzers-research-frontier
BCL/API design standards for public surface
dotnet-api-design-standards
Provenance and maintenance
Phantom symbols still phantom: rerun the Recipe 1 reflection probe against ~/.nuget/packages/moq/4.18.4/lib/net6.0/Moq.dll โ expect the arity-0 and arity-1 Moq.Language.IReturns names NOT FOUND, the arity-2 name and Moq.GeneratedReturnsExtensions exists. Delete the phantom discussion if #1243's fix removes/repurposes the properties: grep -n "IReturns =>" src/Common/WellKnown/MoqKnownSymbols.cs
Void-Setup FN still live: rerun the Recipe 2 snippet โ Moq1200 on GetValue() only; if DoVoid() starts reporting, #1270's pinned-FN rows have been superseded. Gate source: grep -n "IsGenericMethod" src/Common/ISymbolExtensions.Moq.cs (lines 42, 62 as of 2026-07-02)
Harness path unchanged: ls .github/skills/moq-analyzers-diagnostics-and-tooling/scripts/run-analyzer-on-snippet.sh
Roslyn pin: grep -n "Microsoft.CodeAnalysis.CSharp\"" Directory.Packages.props (4.8 as of 2026-07-02); Recipe 5 probes must track it
KnownSymbols test template: ls tests/Moq.Analyzers.Test/Common/MoqKnownSymbolsTests.*.cs
Host-compat maxima: grep -n "_MaxSystemCollectionsImmutable\|8.0.0.0" build/targets/packaging/Packaging.targets .github/workflows/main.yml | head
Load-test matrix legs: count tfm: entries under analyzer-load-test: in .github/workflows/main.yml (9 as of 2026-07-02)
PerfDiff thresholds: grep -rn "Threshold.Parse" src/tools/PerfDiff/BDN/Regression/ (35%; 5%+0.5ms ร2; 250ms; 100ms as of 2026-07-02)
Test count: dotnet test --settings ./build/targets/tests/test.runsettings summary (3,357 + 4 as of 2026-07-02); PackageTests sandbox caveat holds only where the git remote is not a github.com URL
Moq overload counts (20 vs 19 Returns; the 4.18.4-only addition is Returns(InvocationFunc) โ Returns(Delegate) exists in both): dotnet-inspect member "IReturns<TMock, TResult>" --package Moq@4.18.4 --all and @4.8.2
Frontmatter stays parser-safe: python3 -c "import yaml; print(len(yaml.safe_load(open('.github/skills/moq-analyzers-proof-toolkit/SKILL.md').read().split('---')[1])['description']))" โ expect the full description length, not an error or a truncated count
Shipped DLL list (3 files): grep -n "PackagePath=\"analyzers/dotnet/cs\"" src/Analyzers/Moq.Analyzers.csproj
