codegraph/docs/design/csharp-kernel-port-checklist.md

C# kernel port (R7b) — the bug-for-bug checklist

Status: PORT COMPLETE (2026-07-20) — walker codegraph-kernel/src/csharp.rs, all gates passed (parity sweeps 0-diff on serilog 211/216 / Newtonsoft.Json 914/945 / jellyfin 2104/2105 — every deferral matching §arch-6's predictions; full-init dump gates byte-identical ×3; kernel-csharp-parity suite + grammar row; suite ×2 under CODEGRAPH_KERNEL_EXPECT=1; DEFAULT_ROUTED += csharp). This doc remains the quirk reference for the walker. Survey basis: every TS-side branch a .cs file exercises, with file:line anchors as of f1ca991 (HEAD at survey time, clean main). Every grammar-shape claim below was probed against the vendored tree-sitter-c-sharp 0.23.5 wasm (src/extraction/wasm/tree-sitter-c_sharp.wasm — note the underscore filename); probe scripts + raw outputs live in the survey session scratchpad (/private/tmp/claude-501/-Users-colby-Development-CodeGraph-codegraph/0c11bda1-0b19-4fec-bcd9-d0cb4b2d6e8a/scratchpad/svy-csharp/: probe1-core.mjs, probe2-shapes.mjs, probe3-edge.mjs, census-wasm.mjs, error-incidence.mjs, blank-impl.mjs + probe*-out.txt). Read WITH docs/design/rust-kernel-migration-plan.md (§0a recipe, §5 gates) and the rust/ccpp checklists (format precedents). Blocking findings: none — the vendored wasm is table-identical to the crates.io 0.23.5 crate (below), so no grammar bump is needed; grammar prep is a Cargo pin + parity-test entry only.

Grammar provenance (verified, not assumed):

• Vendored wasm landed in PR #717 (commit 80db274e, 2026-06-07 — the #237 primary-constructor fix), replacing tree-sitter-wasms' ABI-13 build. The commit message says "tree-sitter-c-sharp 0.23.5 (ABI 15)" but does NOT claim a parser.c sha-match, so this survey verified compatibility directly against the crates.io tree-sitter-c-sharp-0.23.5 tarball (src/parser.c sha256 0a2651e4…, src/scanner.c sha256 00920daa…; upstream tag v0.23.5 → commit cac6d5fb):
  • wasm ABI 15 == parser.c LANGUAGE_VERSION 15;
  • wasm stateCount 8053 == parser.c STATE_COUNT 8053;
  • wasm nodeTypeCount 533 == SYMBOL_COUNT 530 + ALIAS_COUNT 3;
  • wasm fieldCount 26 with a field-name set identical to the crate's node-types.json (accessors…value);
  • named node-kind set: wasm ⊆ crate exactly (the 9 crate-only names are node-types.json supertypes — declaration, expression, pattern, … — which never instantiate; zero real divergence);
  • the crate ships an external scanner (scanner.c, 12 external tokens) and the wasm embeds it — probed: interpolated raw strings ($"""… {Interp(u)} …"""), raw string literals, and verbatim strings all parse clean.
• Cargo plan: add tree-sitter-c-sharp = "=0.23.5" to codegraph-kernel/Cargo.toml following the exact-pin comment block (the =0.24.2 c/rust rows); crate symbol is tree_sitter_c_sharp::LANGUAGE (a LanguageFn, .into() like the other 0.23-era crates); register "csharp" => Some(tree_sitter_c_sharp::LANGUAGE.into()) in codegraph-kernel/src/langs.rs + add "csharp" to LANGUAGES. The crate's build.rs compiles parser.c and scanner.c (both in the tarball) — no extra work. __tests__/kernel-grammar-parity.test.ts (id-by-id ABI + node-kind + field-table compare) is the real gate and needs a csharp row; no wasm change and no TS-side behavior change — the production wasm stays exactly as shipped since #717, so this port has NO grammar-bump-first step.

Architecture decisions

1. preParse stays TS-side — already hoisted, port NOTHING. csharpExtractor.preParse = blankCsharpPreprocessorDirectives (languages/csharp.ts:26, #237) blanks #if/#elif/#else/#endif directive LINES (both branches of the guarded code are KEPT). The route point already applies it for kernel calls — preParsedSource (kernel/index.ts:82) names csharp explicitly — so both arms parse identical blanked bytes and the deferred-file memo reuses them (takeDeferredPreParse, kernel/index.ts:120; wasm fallback sourceIsPreParsed, tree-sitter.ts:499). Never port the regex to Rust: it is a JS (?m)^-anchored replace (/^([ \t]*)#[ \t]*(if|elif|else|endif)\b[^\n]*/gm) whose ^ matches after \r (JS multiline semantics) and whose [^\n]* EATS the \r of a CRLF line (probed: "…\r\n#if X\r\n…" blanks to "…\r\n \n…" — byte count preserved, \r becomes a space). Both are JS-semantics traps (the #1329 class) that the hoist makes moot.
2. ASP.NET repos take the DECODED path, not raw buffers. aspnetResolver (resolution/frameworks/csharp.ts:11, languages: ['csharp'], registered in frameworks/index.ts:62) has an extract() hook (line 133), and parse-worker.ts:93-100 forces any language with an applicable framework extract() onto the decoded extractFromSource path. detect() (csharp.ts:15) fires on .csproj AspNetCore markers, Program.cs/ Startup.cs shapes, or controller-source signatures — so web-app repos (jellyfin-class) decode per file while pure libraries (serilog, Newtonsoft.Json) ride the raw buffers-to-store transport. Don't chase a raw-path perf number on an ASP.NET repo and conclude the port is broken.
3. The framework extractor itself needs NO port — regex over raw source (§Frameworks below), runs in extractFromSource:6736-6758 after either arm.
4. One walker module (suggest codegraph-kernel/src/csharp.rs), registered in langs.rs; per-file has_error() → defer: like every walker. java.rs is the skeleton (§java.rs mapping below) — same namespace-node concept, same field/constant split, same static-member/value-ref/fn-ref chassis.
5. .cs → csharp at detectLanguage (grammars.ts:87), wasm filename tree-sitter-c_sharp.wasm (grammars.ts:31), vendored-set membership at grammars.ts:292, provenance comment at grammars.ts:252-261. No content sniffing, no dialects (.cshtml/.razor are language razor, a T3 standalone extractor — NOT this port). MAX_FILE_SIZE (1 MiB) and generated-file skips are orchestrator/TS-side and shared.
6. Deferral expectations (measured on the gate repos, post-blank = what the kernel sees): serilog 5/216 = 2.31% (raw 8.33% — the blanking hoist halves it), Newtonsoft.Json 31/945 = 3.28% (raw 6.88%), jellyfin 1/2105 = 0.05%. Keep the sweep default --max-deferral 0.1 — C# needs NO c/cpp-style 0.5 exemption. The residual error class is grammar-inherent both-branches-kept damage (#if FEATURE_DEFAULT_INTERFACE around interface members in serilog's ILogger.cs; half-expression #if HAVE_DATE_TIME_OFFSET guards in Newtonsoft's JsonReader.cs) — those files error on BOTH arms and defer by policy. C# 12 collection expressions ([a, b]) parse natively (probed) — the lone jellyfin error is unrelated.

Extractor config (languages/csharp.ts — 163 lines, read it whole)

Types: functionTypes=[] — C# has NO function branch anywhere (this single fact kills several generic paths below: no nested-fn extraction, no arrow-name recovery, extractMethod's fallback-to-extractFunction is unreachable on non-erroring files). classTypes=[class_declaration, record_declaration] with classifyClassNode (csharp.ts:69): a record_declaration with an anonymous struct keyword child → 'struct', else 'class' (probed: EVERY record form is record_declaration — record struct / readonly record struct included; record_struct_declaration in structTypes is forward-compat only, the grammar has no such node). methodTypes=[method_declaration, constructor_declaration]; interfaceTypes=[interface_declaration] (no interfaceKind → kind 'interface'); structTypes=[struct_declaration, record_struct_declaration]; enumTypes=[enum_declaration]; enumMemberTypes=[enum_member_declaration]; typeAliasTypes=[] (a using Alias = … NEVER makes a type_alias — it goes through extractImport, quirk below); packageTypes=[namespace_declaration, file_scoped_namespace_declaration]; importTypes=[using_directive]; callTypes=[invocation_expression]; variableTypes=[local_declaration_statement]; fieldTypes=[field_declaration]; propertyTypes=[property_declaration]. nameField=name, bodyField=body, paramsField=parameters, returnField=type (note: type is a dead value for methods — the 0.23.x grammar renamed the method return field to returns, and both consumers, getReturnType and extractCsharpTypeRefs, read returns themselves; returnField is only reachable via the generic extractTypeAnnotations path which csharp short-circuits out of).

Hooks PRESENT (port each exactly):

• preParse — TS-side, hoisted (§arch-1). Not ported.
• getReturnType = extractCsharpReturnType (csharp.ts:43) — reads the returns field; predefined_type (void/int/string/…) or array_type → undefined; else raw text trim → strip trailing \?+ (nullable) → strip /<[^>]*>/g (generics) → last .-segment → must match /^[A-Za-z_]\w*$/ else undefined. QUIRKS (same class as rust): the non-nested <[^>]*> strip breaks on nested generics — Task<List<Foo>> → "Task>" → regex fails → undefined (single-level Task<Widget> → Task survives); Ns.Foo → Foo; Foo? → Foo. Constructors have no returns field → undefined. This feeds the #645/#608 chained-call resolution (name-matcher.ts:2156 matchDottedCallChain) — emission shape must hold.
• getVisibility (csharp.ts:102) — scan ALL children (node.child(i)) for type modifier; FIRST text match among public/private/protected/internal wins; none → 'private'. Modifiers are individual named modifier children (probed — NO Java-style modifiers wrapper). So protected internal → 'protected', private protected → 'private'. Called for classes, structs, enums, methods, properties, fields (NOT interfaces — extractInterface never asks).
• isStatic (csharp.ts:115) — any modifier child with text static.
• isConst (csharp.ts:127) — const modifier → true; else static AND readonly both present → true. Consumed ONLY by extractField's kind gate (tree-sitter.ts:2058-2062) and extractVariable:2546 (moot — see §local_declaration_statement).
• isAsync (csharp.ts:140) — any modifier child with text async. WORKS for C# (unlike rust's dead-code isAsync) — probed: async is a direct modifier child of method_declaration.
• extractImport (csharp.ts:149) — signature = trimmed full node text (UTF-16 substring). moduleName = FIRST namedChild of type qualified_name's text, else FIRST namedChild of type identifier's text, else null. Probed shapes and the resulting QUIRKS (all PRESERVE):
  • using System; → identifier → System.
  • using System.Collections.Generic; → qualified_name → full dotted text.
  • using static System.Math; → qualified_name → System.Math (the static keyword is an anonymous token — no trace).
  • global using GlobalNs.Thing; → same as a plain using (the global keyword is anonymous) → GlobalNs.Thing.
  • using Alias = Some.Type<T>; → the find(qualified_name) hits the TARGET, whose raw text INCLUDES generic args — moduleName System.Collections.Generic.Dictionary<string, int> (probed verbatim).
  • using Short = SomeType; (single-identifier target) → no qualified_name → find(identifier) returns the FIRST identifier, which is the name: field = the ALIAS → moduleName Short, the target SomeType is lost.
  • The hook never returns null on real shapes probed; if it did, tree-sitter.ts:3350 (if (this.extractor.extractImport) return;) means NO import node at all — mirror that gate.

Hooks ABSENT (the walker must NOT do these): getSignature — C# methods, constructors and classes carry signature: undefined (only properties/fields get signatures, built inline by their extractors); getReceiverType (receiver machinery inert — extractMethod:1799 owner-lookup never runs); resolveName, recoverMangledName, isMisparsedFunction, isExported (every node's isExported is undefined; the file node's is false), resolveBody, classifyMethodNode, extractPropertyName, extraClassNodeTypes, extractModifiers, synthesizeMembers (no Lombok analogue — confirmed; the java.rs Lombok section has no C# counterpart), extractBareCall, visitNode hook, skipBodilessClass (bodiless CLASSES still mint nodes — but see extractStruct/extractEnum's own body gates), methodsAreTopLevel, interfaceKind.

The namespace node (extractFilePackage — the biggest structural quirk)

extract() (tree-sitter.ts:531-532) calls extractFilePackage(root) ONCE, before the walk: it scans root's DIRECT namedChildren for the FIRST packageTypes node, calls extractPackage (csharp.ts:86 — name field ?? first qualified_name/identifier child; probed: both namespace forms carry a name: field, identifier or qualified_name), and mints ONE kind:'namespace' node (name = dotted text, e.g. My.App; id = generateNodeId(file,'namespace','My.App',line); contains edge from the file node) which stays PUSHED for the ENTIRE file walk. Consequences (all probed, all PRESERVE):

• qualifiedNames join with :: but the namespace segment keeps its dots: class Widget in namespace My.App → QN My.App::Widget, method → My.App::Widget::Build.
• visitNode has NO packageTypes branch — namespace_declaration falls through the whole ladder and its children are visited generically. So: a NESTED namespace (namespace Outer { namespace Inner { class Deep } }) leaves NO trace of Inner — Deep's QN is Outer::Deep; a file with TWO top-level namespaces scopes the SECOND one's types under the FIRST's node — namespace Second { class Other } after namespace Outer {…} → Other has QN Outer::Other and a contains edge from the Outer namespace node.
• A file-scoped namespace My.App.Sub; behaves identically (node spans just the declaration line).
• using directives INSIDE a namespace block are reached by the generic walk and behave exactly like top-of-file ones; ALL import refs and import nodes in a namespaced file hang off the namespace node (nodeStack top), not the file node.
• isInsideClassLikeNode() (1486) checks the stack TOP against class/struct/interface/trait/enum/module — namespace is NOT class-like, so top-level types under a namespace extract exactly like file-scope ones.

tree-sitter.ts branches (anchors as of f1ca991)

visitNode dispatch — what each C# node hits

Node	Branch	Behavior
class_declaration	classTypes:1005 → classify:1007 → extractClass:1679	kind class; body walk via declaration_list; skipChildren
record_declaration	classTypes → classify	struct keyword child → extractStruct:1869 (record struct); else extractClass. Bodiless record Empty; still mints a class node (no skipBodilessClass; body-walk loop then iterates the record node's own children harmlessly)
struct_declaration	structTypes:1059 → extractStruct:1869	body (declaration_list) required: bodiless struct Fwd; mints NO node (1876 exempts only record_declaration)
interface_declaration	interfaceTypes:1054 → extractInterface:1834	kind interface; NO visibility read; members visited with interface pushed (class-like) — so interface methods/properties become method/property nodes
enum_declaration	enumTypes:1064 → extractEnum:1914	body enum_member_declaration_list required (bodiless → no node); extractInheritance sees base_list → the underlying type : byte emits an extends ref named byte (quirk, §inheritance); enum_member_declaration children → extractEnumMembers:1958 — name field path: ONE enum_member node per member, positioned at the member node (attributes included in its span), values/attributes ignored; non-member children (preproc_*, comment) → visitNode (no-op)
method_declaration	methodTypes:1027 → extractMethod:1737	classifyMethodNode absent → always extractMethod. Gate 1747 passes via class-like (a method_declaration outside a type does not occur in non-erroring C# — top-level void M(){} parses as local_function_statement, probed); bodyless interface/partial signatures mint nodes with no body walk; expression-bodied methods have body: arrow_expression_clause (a real body FIELD, probed) → walked
constructor_declaration	methodTypes → extractMethod	name field = the class-name identifier → method node named like the class; returnType undefined; constructor_initializer (: base(args) / : this(args)) is a sibling of the body field → NEVER walked → calls inside initializer args are LOST (probed); expression-bodied ctor body = arrow_expression_clause → walked
property_declaration (inside class-like)	propertyTypes:1075 → extractProperty:1986	property node + scanFnRefSubtree (capture-only) + skipChildren → accessor bodies (get { … }, get => …) and the => expr value clause are NEVER walked — calls inside property getters/setters/expression bodies emit NOTHING (only fn-ref candidates). §property below
field_declaration (inside class-like)	fieldTypes:1084 → extractField:2046	field/constant nodes per declarator + scanFnRefSubtree + skipChildren → field initializers emit no calls/instantiates/static-member refs (fn-ref candidates only). §field below
local_declaration_statement	variableTypes:1098 (only reachable at top level — global statements; body locals go through visitFunctionBody instead)	not class-like → extractVariable:2538 → generic fallback (2863-2881) finds no direct identifier/variable_declarator children (the declarator nests inside variable_declaration, probed) → ZERO nodes minted; isClassScopeConstantAssignment (1508) needs node.type assignment → never true. skipChildren=true + scanFnRefSubtree → a top-level var builder = WebApplication.CreateBuilder(args); produces NO node, NO calls ref, NO instantiates — only fn-ref candidates. PRESERVE
using_directive	importTypes:1209 → extractImport:3170	hook (§config) → import node + ONE generic imports ref {fromNodeId: nodeStack top (namespace node if present, else file), referenceName: moduleName, line/col of the directive}; no per-binding emitter (the TS/py/rust/php/ruby ladder at 3197-3234 excludes csharp)
invocation_expression (top level — global statements)	callTypes:1248 → extractCall:3684	fires with caller = file/namespace node; children still visited (no skipChildren) so nested invocations recurse
object_creation_expression (top level, expression-statement position)	INSTANTIATION_KINDS:354/1255 → extractInstantiation:4610	+ findAnonymousClassBody:4815 checks for a class_body/declaration_list child — probed: C# object_creation children are [new, type, argument_list, initializer_expression] — the anon branch NEVER fires on non-erroring C# (C# has no anonymous classes; object initializers are initializer_expression). Mirror the check anyway (java.rs:1550 already has it)
global_statement / expression_statement / await_expression / lambdas / namespace_declaration / preproc_* / global_attribute / delegate_declaration / event_declaration / event_field_declaration / operator_declaration / conversion_operator_declaration / indexer_declaration / destructor_declaration / local_function_statement / type_parameter_constraints_clause	no branch	fall through → children visited. Consequences (all probed, all PRESERVE): delegates mint NO node; events mint NO node; operators/conversions/indexers/destructors mint NO node but their bodies' calls attribute to the ENCLOSING CLASS (visitNode descends into accessor/body blocks with the class still on top); local functions mint NO node (functionTypes empty — visitFunctionBody:5245 gate never passes) and their bodies' calls attribute to the enclosing method (or file node at top level); where T : IEntity constraint types emit NOTHING (constraints are class-node children outside the body — never visited by extractClass's body loop, and extractCsharpTypeRefs doesn't walk them)
property_signature / method_signature / impl_item / export/store branches	TS/rust-only node types	never C#

Node creation, IDs, qualified names

• createNode (1308): id = generateNodeId(filePath, kind, name, startRow+1) = `${kind}:${sha256(`${filePath}:${kind}:${name}:${line}`).hex.slice(0,32)}` (tree-sitter-helpers.ts:18). File node id = literal file:${filePath} (tree-sitter.ts:509). Same-(kind,name,line) ID collisions are routine — dedupe/self-checks compare ID STRINGS (node_ids vec pattern; partial methods partial void Hook(); + partial void Hook() { } are two method nodes on different lines — fine).
• resolveBody endLine extension (1329) is a no-op (no hook).
• contains edge from nodeStack top for every created node (1363); captureValueRefScope after every create (1374).
• qualifiedName = stack names joined :: (buildQualifiedName:1447; namespacePrefix always empty for csharp — it's cpp-only). No receiver QNs (no getReceiverType).
• File node: kind file, name basename, qualifiedName = filePath, endLine = source.split('\n').length (post-preParse source — identical bytes both arms), isExported false.

extractClass / extractStruct / extractInterface / extractEnum

• extractClass (1679): node = class/record; docstring (getPrecedingDocstring), visibility, isExported=undefined → createNode(kind 'class') → extractInheritance (1704) → extractCsharpPrimaryCtorParamRefs (1707) → extractDecoratorsFor (1710, NO-OP for C# — §decorators) → push → body loop over declaration_list namedChildren via visitNode → pop. No synthesizeMembers. EXACT ORDER of the three pre-body calls is emission-order-sensitive.
• extractStruct (1869): body gate (record exemption 1876); createNode('struct') → extractInheritance (1891) → primaryCtor refs (1895) → body walk only when body exists (bodiless positional record struct M(…); mints the node, walks nothing). NOTE extractStruct does NOT call extractDecoratorsFor — struct attributes emit nothing anyway.
• extractInterface (1834): createNode('interface', {docstring, isExported}) — NO visibility field (never asked); extractInheritance; body loop with interface pushed. Interface members: Task<T> Get(int id); → method node (no body); string Label { get; } → property node; default-impl methods (arrow or block body) → method node WITH body walk.
• extractEnum (1914): body required; createNode('enum', {docstring, visibility, isExported}); extractInheritance (→ the : byte extends quirk); body loop: enumMemberTypes children → extractEnumMembers (name-field path: 1960-1963 — one enum_member node, NO docstring, NO value), everything else → visitNode. Enum members with attributes: the member NODE's position starts at the attribute_list (probed — [Obsolete] ReadAsInt = 1 spans from [).

extractProperty (1986) — property_declaration

docstring; visibility; isStatic (?? false — always a concrete bool). Name = name field (property_declaration always has one, probed). Type/signature: isTsJsField false → typeNode = FIRST namedChild whose type is NOT modifier/modifiers/identifier/accessor_list/accessors/equals_value_clause (2013-2017); signature = typeText name (the .replace(/^:\s*/,'') is inert for C#) or bare name. QUIRKS (probed, PRESERVE):

• A property whose declared type is a BARE identifier (public Widget Parent { get; init; }) finds NO typeNode (identifier is excluded) → signature = "Parent" — identifier-typed properties lose their type in the signature (predefined_type string, generic_name List<Foo>, qualified_name, nullable_type etc. all keep theirs).
• An expression-bodied property (public int Computed => MaxItems + 1;) has children [modifier, predefined_type, identifier, arrow_expression_clause (value: field)] → typeNode = predefined_type → signature "int Computed"; the arrow clause is NEVER walked (calls inside lost).
• { get; } = new(); initializers: the value: implicit_object_creation and the accessor_list are both skipped/excluded → no refs, no instantiates.

Then extractDecoratorsFor (no-op) and extractTypeAnnotations (2037) → extractCsharpTypeRefs — the type field IS walked for refs (so public List<Foo> Items emits references List + Foo even though the signature kept the raw text). Return value feeds no body walk (the classifyMethodNode initializer-walk path at 1031-1047 is TS-only).

extractField (2046) — field_declaration

• kind (2058-2062): (java|csharp) && isConst(node) → constant (const fields, static readonly fields), else field. Evaluated once per DECLARATION — all declarators share it.
• Declarators: direct variable_declarator filter finds none → the C# wrapper path (2070-2075): the variable_declaration child's variable_declarator children (probed: field_declaration → [modifier…, variable_declaration[type field, declarator, declarator…]]).
• typeText (2110-2116): first namedChild of the variable_declaration that isn't modifiers/modifier/variable_declarator/variable_declaration/ marker_annotation/annotation → the type node's raw text.
• Per declarator: name = name field (?? first identifier); signature = `${typeText} ${name}`; createNode(kind, name, decl — the declarator node, so line/col/ID anchor to the declarator); then extractDecoratorsFor(node, id) (no-op) and extractTypeAnnotations(node, id) → extractCsharpTypeRefs on the OUTER field_declaration — which walks the variable_declaration's type field (5905-5909) → multi-declarator fields (Foo A, B;) emit the type refs ONCE PER DECLARATOR, each from its own field node.
• docstring/visibility/isStatic computed once from the outer declaration, shared by all declarators. The PHP property_element and bare-fallback branches (2078-2154) are unreachable for C#.
• event_field_declaration is NOT a field_declaration — no nodes (§dispatch).

extractMethod (1737) — method_declaration + constructor_declaration

receiverType = undefined (no hook) → gate 1747 passes via class-like → name = name field (constructor: the class name; explicit interface impl void IDisposable.Dispose(): name = Dispose — the explicit_interface_specifier is a separate child, probed); no isMisparsedFunction. Node props: docstring, signature: undefined (no getSignature hook), visibility, isAsync (real), isStatic, returnType (getReturnType — constructors undefined). Then extractTypeAnnotations (1816 → extractCsharpTypeRefs: returns-field refs FIRST, then per-parameter type refs — order matters), extractDecoratorsFor (1819, no-op), push, walk the body FIELD only (block or arrow_expression_clause), pop. The receiver-contains lookup (1799-1813) never runs (no receiverType).

extractCall (3684) — the C# paths

Generic else-branch (4312+): func = childForFieldName('function') ?? namedChild(0). C# invocation_expression always has a function: field (probed). The 4364 member_expression/field_expression branch does NOT match member_access_expression, so C# calls route as:

1. func.type === 'member_access_expression' → the csharp branch (4502-4517): recv = expression field, methodName = name field text.
   • recv is invocation_expression (chained call Foo.Create(1).Bar()): innerFunc = recv's function field; innerCallee = innerFunc raw text with /\s+/g stripped; calleeName = `${innerCallee}().${methodName}` (empty innerCallee → bare methodName). C# re-encodes EVERY call-receiver chain — no capitalization gate (unlike kotlin/scala): GetThing().Bar() → GetThing().Bar; multi-line Foo.Create(1)\n .Bar() → Foo.Create().Bar (whitespace stripped on the INNER only).
   • recv anything else → calleeName = RAW full text of the member_access_expression (getNodeText — UTF-16 substring, whitespace and newlines INCLUDED). Probed consequences, all PRESERVE: this.Run(x) → this.Run (SKIP_RECEIVERS never applies — the 4400 set is in the branch C# doesn't take); base.Method() → base.Method (recv is the anonymous-token base via the field — childForFieldName returns it); _repo.Save(x) → _repo.Save; builder\n .Services\n .AddSingleton<IRepo, Repo>() → the full multi-line text builder\n .Services\n .AddSingleton<IRepo, Repo> (generic args included, newlines included); literal receivers are NOT filtered — "lit".ToUpper() → "lit".ToUpper (LITERAL_RECEIVER_TYPES is consulted only in the non-C# branch); p!.Force() → p!.Force; 2-hop reads keep everything.
2. func.type === 'scoped_identifier' (4499) — never C# (no :: node).
3. else → calleeName = raw func text: bare Helper() → Helper; generic invocation Generic<int>(local) → func = generic_name → Generic<int> kept verbatim (the template strip at 4542 is c/cpp-gated); nameof(Widget) → func = identifier nameof → a calls ref named nameof (probed — nameof is a plain invocation in this grammar); conditional access request?.Method() → func = conditional_access_expression → raw text request?.Method; delegate parens (myDel)(x) → func = parenthesized_expression → text (myDel) → the conversion regex at 4530 (/^\(\s*\*?\s*([A-Za-z_][\w.]*)\s*\)$/) FIRES → myDel (the one shared normalization C# actually hits — port it).

Post-processing: template strip (4542) and cpp fn-ptr fan-out (4556) are c/cpp-gated — NOT csharp. Final push: one calls ref {fromNodeId = nodeStack top, referenceName, line = call startRow+1, column = call startColumn (UTF-16)}. Children of the invocation are still traversed afterward (both walkers), so inner calls of a chain emit separately: Foo.Create(1).Bar() → refs Foo.Create().Bar AND Foo.Create. typeof(…), default(…), casts, is/as patterns, element access, switch expressions, ??/ternary, interpolated-string interpolations, tuple expressions: no dedicated handling — plain recursion reaches any invocation_expression inside them (probed shapes in probe3-out.txt).

extractInstantiation (4610) — object_creation_expression

ctor = constructor/type(hit)/name/namedChild(0) fields → the type: field (probed). Generic path: raw text → strip from first < (new List<Foo>() → List) → vbnet paren strip (inert) → keep last ./:: segment (new Ns.Foo() → Foo) → trim → instantiates ref at the object_creation_expression's position. Fires from visitNode:1255 (expression statements at top level) AND visitFunctionBody:5145. QUIRKS, PRESERVE: implicit_object_creation_expression (new()) and anonymous_object_creation_expression (new { X = 1 }) and array_creation_expression (new Widget[10]) are NOT in INSTANTIATION_KINDS → no instantiates refs (target-typed new() — everywhere in modern C# — is invisible); object/collection initializer args and new[] { Mk() } contents still recurse to their own calls. Top-level var w = new Widget(); emits nothing at all (§local_declaration_statement).

extractStaticMemberRef (4750) — csharp ∈ STATIC_MEMBER_LANGS (345)

Called for EVERY node in visitFunctionBody (5218) — body walker only (never visitNode, so class-level field initializers and top-level statements emit no static refs). Node gate: MEMBER_ACCESS_TYPES (323) contains member_access_expression. Skip when the access IS a call's callee (4772-4779: parent ∈ callTypes && callee.startIndex === node.startIndex — so Console.WriteLine(…)'s access is skipped but DoThing(Constants.MAX)'s argument is not). recv = expression field (hit) → must be type identifier/type_identifier/simple_identifier/name/scoped_type_identifier — for C# only identifier occurs — and text must match /^[A-Z][A-Za-z0-9_]*$/ → references ref {name = recv text, line/col of RECV}. Probed: ReadType.ReadAsDouble → ref ReadType; Outer.Inner.DEEP → the outer access's recv is a member_access (skip) but the INNER Outer.Inner emits ref Outer; lowercase receivers (u.Age, builder.Services) → nothing; this.X → recv type this → nothing.

Decorators/attributes — NO-OP for C# (probed, PRESERVE)

extractDecoratorsFor (4897) accepts node types decorator/annotation/ marker_annotation/attribute (+solidity modifier_invocation). C# attributes are attribute_list nodes containing attribute children, and attribute_list is (a) a DIRECT child of the declaration (class/method/enum-member — probed), so the direct-children scan sees attribute_list (not in the set → skipped, and its attribute grandchildren are never reached); (b) never inside a modifiers wrapper (C# has none); (c) as a PRECEDING sibling — only for global_attribute, which is never a decorated declaration. Net: zero decorates refs for C#. The walker needs no decorator code — but keep the call sites' ORDER slots (they emit nothing). Corollary (contrast rust): an attribute between a doc comment and its declaration does NOT break the docstring chain — the attribute_list is a child of the declaration, so the comment remains previousNamedSibling (probed: /// doc + [Attr] + method → docstring found).

Inheritance — extractInheritance (5291), base_list branch (5577-5593)

The ONLY child type that matters for C# types is base_list (extends/ implements/superclass/base_class_clause etc. never occur). The branch iterates ALL namedChildren of base_list with NO type filter and emits ONE extends ref each (C# never emits implements from extraction — the comment at 5574-5576 documents the deliberate conflation; interface-vs-class splitting happens at resolution/synthesis):

• identifier → text (BaseItem, IWidget).
• generic_name → its FIRST identifier child's text (ClientBase<Widget> → ClientBase) — but position = the generic_name node.
• qualified_name → FULL dotted text (Sys.ICloneable — no last-segment reduction).
• QUIRK (probed): a C# 12 class primary-ctor base class Svc(…) : Base(repo), IThing parses base_list children as [identifier(Base), argument_list((repo)), identifier(IThing)] → emits extends Base, extends (repo) (!), extends IThing. The (repo) ref is garbage that never resolves — PRESERVE it.
• QUIRK (probed): a RECORD's base-with-args wraps differently — record UserDto(…) : BaseDto(Name), IThing → base_list children are [primary_constructor_base_type, identifier] → emits extends BaseDto(Name) (full text, argument list included) + IThing.
• QUIRK (probed): an enum's underlying type enum ReadType : byte puts predefined_type(byte) in base_list → extends ref byte (likewise : int, etc.).

extractInterface/extractStruct/extractEnum all route through the same branch. The 5652 recursion (field_declaration_list/class_heritage) never matches C#.

Type-annotation references — csharp ∈ TYPE_ANNOTATION_LANGUAGES (5753)

extractTypeAnnotations (5788) short-circuits into extractCsharpTypeRefs (5798-5801) — the generic params/return/type_annotation path below it never runs for C#. extractCsharpTypeRefs (5893):

1. directType = type field ?? returns field → walkCsharpTypePosition (methods: returns; properties: type; constructors: neither).
2. a variable_declaration child's type field (fields) → walk.
3. parameters field → per parameter child (type filter — probed: bracketed_parameter_list of indexers never reaches here since indexers aren't dispatched) → its type field → walk.

walkCsharpTypePosition (5955): predefined_type → nothing; identifier → references ref unless name ∈ BUILTIN_TYPES (5768 — port the WHOLE set verbatim: the Java/C# row int/long/short/byte/float/double/char, plus cross-language rows — a C# type named String/Boolean/error IS suppressed (Scala/Go rows) while Task/List/IRepo/dynamic are emitted — probed: dynamic parses as identifier → a references ref named dynamic); qualified_name → LAST .-segment as referenceName (position = the whole qualified_name node) unless builtin; tuple_element → its type field only (element names gated out); everything else (generic_name, nullable_type, array_type, pointer_type, tuple_type, ref_type, scoped_type, …) → recurse ALL namedChildren — so List<Foo> emits List AND Foo; Task<List<Foo>> emits Task, List, Foo; Foo?/Bar[] unwrap; generic args inside type_argument_list all surface. Called from extractMethod (params+returns), extractProperty (type), extractField (per declarator), and extractCsharpPrimaryCtorParamRefs.

extractCsharpPrimaryCtorParamRefs (5938) — from extractClass:1707 and extractStruct:1895 (NOT interface/enum): finds a parameter_list child BY TYPE (the primary ctor hangs as an unnamed-field child — probed on class, record, record struct), walks each parameter's type field → references refs from the TYPE node (class Svc(IRepo repo, ICache cache) → refs IRepo, ICache). Extension-method this params ride the normal parameter path (the this is a modifier child; type field still walked).

Body-local type annotations: NONE. visitFunctionBody:5230's variable_declarator branch calls extractVariableTypeAnnotation (6074), which looks for a type_annotation child — C# has no such node (the type is a field of variable_declaration) → structurally inert. Cast/typeof/is/as/catch types emit nothing (§extractCall).

Docstrings (tree-sitter-helpers.ts:95)

/// XML doc comments and // comments are comment nodes (probed); consecutive preceding named siblings accumulate (unshift → source order); cleanCommentMarkers strips ^\/\/[/!]?\s? per line — so the stored docstring is the XML markup minus slashes (<summary>Doc line.</summary>). DOCSTRING_WRAPPER_TYPES contains no C#-relevant wrappers (variable_declaration /variable_declarator ARE in the set but no C# docstring call site passes those nodes — extractField/extractProperty pass the outer declaration). Block /** */ comments are also comment nodes and /*-stripped. Attributes don't break the chain (§decorators). **Reuse docstring::preceding_docstring

• js_multiline_strip as-is** — the CRLF ^-after-\r semantics (#1329) are already handled there; C#'s XML docs on CRLF checkouts hit exactly that path. Docstring recipients: class/record/struct/interface/enum/method/ctor/property/ field (NOT enum members, NOT the namespace node, NOT imports).

Value-reference edges — csharp ∈ VALUE_REF_LANGS (401)

Port the full machinery (crib java.rs:1246 flush_value_refs — Java's cases are csharp's minus/plus the declarator switch): CODEGRAPH_VALUE_REFS=0 kill; MAX_VALUE_REF_NODES=20_000 caps the prune scan and each reader scan; isGeneratedFile skip.

• Targets (captureValueRefScope:735): created nodes of kind constant/variable, name length ≥3 AND /[A-Z_]/, parent scope id starting file:/class:/module:/struct:/enum:. For C# that means const / static readonly fields (kind constant) inside class:/struct: parents — namespace: parents do NOT qualify (deliberate: a namespace-scoped… doesn't exist in C# anyway), and C# mints no variable nodes at all. Last same-named target wins the map; counts accumulate per name.
• Reader scopes: every function/method/constant/variable node — for C#: methods (ctors included) + constant fields.
• Shadow prune (803-878): DFS the whole tree; C#-live cases of the declarator switch: variable_declarator (818) → bump(namedChild(0)) — counts field declarators (the targets) AND method-body locals AND top-level-statement declarators (the shadow sources); property_declaration (856) fires but is inert — no variable_declaration child, and firstSimpleIdentifier (tree-sitter.ts:261) hunts simple_identifier which C# lacks → bump(null). All other cases (const_item, assignment, init_declarator, …) are other grammars' node types — a C# tree never contains them. After the scan: declCount > fileScopeCount → target deleted (a method-local var MaxItems = … shadows the class const).
• Emission (880-930): per reader scope, stack-DFS its node subtree (push-children-in-order / pop-last → REVERSE-index traversal order — mirror exactly, dedupe is first-wins per (scope,target)); each identifier whose text maps to a target, target ≠ self, name ≠ scope's own name → EDGE {source: scopeId, target: targetId, kind:'references', metadata:{valueRef:true}}. The constant/name/simple_identifier reader types are other-language rows — inert but harmless to mirror. Dart/Pascal sibling-body pull (891) is inert. Flush order: fn-ref candidates flush FIRST (unresolvedReferences), then value refs (edges) — extract():538-539.

Function-as-value capture (#756) — CSHARP_SPEC (function-ref.ts:250)

idTypes={identifier}; dispatch: argument_list→args, assignment_expression→rhs(field right) — covers +=/-= event subscription (compound assignment is still assignment_expression, probed), initializer_expression→list (object/collection initializers), variable_declarator→varinit (NO field — the last-named-child path). layers: argument→null (descend named children). special: {member_access_expression}. No unwrap/ungatedModes/addressOfOnly.

• varinit mechanics (function-ref.ts:471-486): C# variable_declarator has no value field → value = LAST namedChild, require ≥2 namedChildren and value ≠ name child (probed: f = x => Compute(x) → [name, lambda_expression]; initializer-less _repo → 1 child → skipped). Destructuring gate (object/array/tuple/struct_pattern) never matches C#.
• rhs param-storage skip (430-444): LHS last-identifier == RHS text → skip (this.status = status). button.Click += OnClick → LHS last-name Click ≠ OnClick → candidate.
• normalizeValue: bare identifier → candidate (NAME_STOPLIST = this/self/super/null/nil/true/false/undefined/new/NULL/nullptr/None — note value, args, and base are NOT stoplisted; base/this can't become candidates anyway, they parse as non-identifier tokens); member_access_expression → normalizeSpecial (738-746): name field required; receiver must be this — expr field type this_expression OR this (the vendored grammar yields the anonymous-token this via the field — probed; the text-prefix fallback exists for field-less shapes) → candidate = the BARE member name (this.HandleThing → HandleThing — NOT this.-prefixed, unlike TS/Java; it then gates against definedHere). C.StaticHandler (type receiver) → NOTHING. Lambdas/anonymous methods → nothing (not idTypes/special).
• Capture fires from visitNode:990, visitFunctionBody:5137, and scanFnRefSubtree (property/field/variable declarations + top-level statements, depth ≤12, capture-only). scanFnRefSubtree's halt list (tree-sitter.ts:606-612) includes the literal type lambda_expression — which IS C#'s lambda node — so at depth>0 the scan STOPS at a lambda in a field/property initializer (Action A = () => Register(H); yields no candidates from inside the lambda), while anonymous_method_expression (delegate() { … }) is NOT in the list and is scanned through. Method-BODY lambdas are unaffected (visitFunctionBody recursion has no halt — capture fires per node).
• Flush gate (flushFnRefCandidates:639): generated-file skip; this.-prefixed names skip the gate (C# never produces them — its this-forms are bare); otherwise name ∈ definedHere ∪ importedNames. definedHere = same-file function/method node NAMES — for C#: methods + constructors (= class names); local functions are NOT nodes so their names don't gate in. importedNames: from imports-kind refs — C# using-refs are dotted → QUALIFIED_IMPORT (./\ separators) admits the LAST segment (using MyApp.Helpers; → Helpers), single-segment using Xunit; → Xunit; the alias-quirk moduleNames ride the same rules. Survivors dedupe on ${fromNodeId}|${name} → function_ref refs.

Closure-collection / other passes

• csharp ∉ CC_LANGUAGES (callback-synthesizer.ts:77 — swift/kotlin only): the closure-collection synthesis pass ignores C#. Nothing to port; nothing to regress.
• Local-variable receiver inference (#1108) and typed-param receivers (#1125/#1129/#1130) are RESOLUTION-side: name-matcher.ts:1164 has the csharp regex rows (= new Logger() and Logger lg;-shaped declared types, covering params via the [=;,)] tail). They consume the recv.Method member-access text extraction emits — the walker just has to reproduce the emission shapes above.
• Chained-call resolution (#645/#608/#750): csharp is in matchDottedCallChain (name-matcher.ts:2156) — consumes the inner().Method encoding + declared return types (getReturnType). Resolution-side; extraction contract pinned above.
• LANGUAGE_FAMILY: csharp+razor = 'dotnet' (name-matcher.ts:149) — the razor extractor (T3, TS-side) resolves against C# nodes; unaffected by the port.

java.rs skeleton mapping (what to crib, what diverges)

Crib directly (same chassis, adjust node kinds): Scope/NodeMeta/Extra structs, create_node + contains + capture_value_ref_scope, push_ref helpers, visibility/is_static/is_const modifier scans (java.rs:405-447 — but C# reads bare modifier children, java reads a modifiers wrapper), extract_field's wrapper-declarator loop (java.rs:704 — C# adds the variable_declaration indirection), extract_enum/extract_enum_members, extract_static_member_ref (java.rs:938 — swap field_access → member_access_expression + expression field), value-ref flush (java.rs:1246 — swap the declarator cases for variable_declarator + inert property_declaration), fn-ref capture/flush (java.rs:1120-1243 — swap JAVA_SPEC for CSHARP_SPEC incl. bare identifiers as idTypes and the this-receiver special), find_anonymous_class_body (java.rs:1550 — keep, unreachable), the package/namespace node (java.rs package_declaration ↔ extractFilePackage semantics — but C#'s is FIRST-CHILD-ONLY with the second-namespace and nested-namespace quirks, and the namespace node kind is namespace in both). DIVERGES from java.rs — do NOT copy: Lombok synthesis (java.rs:1339-1548 — no C# counterpart); method_invocation this.field unwrap + Java's chain encoding (C#'s csharp-branch semantics at tree-sitter.ts:4502 differ: raw full text, no SKIP_RECEIVERS, unconditional re-encode); annotations→decorates (C# emits none); anonymous classes (<T$anon@line> — unreachable for C#); signature_of (C# methods have NO signature); Java's type_list inheritance (C# is the unfiltered base_list loop + its three quirk shapes); getVisibility default (private for C#). csharp-NEW (no java.rs precedent): extractCsharpTypeRefs/walkCsharpTypePosition (the type-ref engine), extractCsharpPrimaryCtorParamRefs, the extractProperty branch (java has no propertyTypes), classifyClassNode record→struct, the extractImport alias/static/global quirks, the local_declaration_statement zero-emission path, preproc_* passthrough.

Frameworks that consume C# extraction artifacts (stay TS-side)

aspnetResolver (resolution/frameworks/csharp.ts) — detect: .csproj AspNetCore refs / Program.cs / Startup.cs / controller-source scan.

• extract() (csharp.ts:133 — regex over RAW source via stripCommentsForRegex, runs in extractFromSource AFTER either arm — NO port needed): emits route nodes with id `route:${filePath}:${line}:${METHOD}:${path}` (NOT hashed), kind route, name `${METHOD} ${path}`, qualifiedName `${filePath}::route:${path}`, language csharp; plus one references ref per handler FROM the route node (framework refs DO carry filePath+language, unlike extraction refs). Covers [HttpGet]-family attributes (bare or with path, class-level [Route] prefix joined) and minimal-API .MapGet("/p", handler) chains. Because it reads RAW source (not extraction output), the port cannot break it — but parse-worker routing (§arch-2) means its presence forces the decoded path.
• resolve() consumes plain unresolved refs by suffix (Controller/Service/Repository/ViewModel/Dto) + directory conventions — extraction-shape-agnostic beyond the referenceName spellings pinned above.

Parity mechanics (all have bitten before — be explicit)

• Emission ORDER per file (rowid-order-sensitive downstream): file node → namespace node (when present) → walk order exactly as the dispatch table above (per declaration: inheritance refs → primary-ctor refs → [decorators: nothing] → body/member walk; methods: type-annotation refs (returns, then params) before the body's calls; fields: per-declarator node → its type refs → next declarator) → flushFnRefCandidates (refs) → flushValueRefs (edges, reverse-index DFS order). Refs carry NO filePath/language (the store denormalizes) — the wire contract is exactly extractFromSource's return.
• generateNodeId inputs: (filePath, kind, name, startRow+1) — name is the EXACT string pinned per branch above (e.g. constructors use the class name; enum members the name-field text; imports the moduleName with its generic-args quirk; the namespace node the dotted package text).
• UTF-16 everywhere: positions/columns (textutil::col16 — verified against the wasm: emoji-preceded call at column 37 in UTF-16 units), every getNodeText slice (raw substring — multi-line callee texts keep newlines), the import signature trim. No .slice(0,100) truncations fire for C# (that path is the variable-initializer signature, unreachable), but signatures built from raw type text are UTF-16 substrings.
• CRLF hazards: the ONLY multiline regexes on the C# path are (a) the preParse blanking — TS-side, hoisted, never ported (§arch-1) — and (b) docstring cleaning — already CRLF-correct via js_multiline_strip (docstring.rs, #1329). The walker itself must add NO (?m)/^/$ regex without the same scrutiny. getReturnType/extractImport regexes are single-line and anchor-free except /^[A-Za-z_]\w*$/ (whole-string match — use Regex::is_match on the full string, \A…\z semantics).
• Defer policy: per-file has_error() → defer: signal (kernel receives BLANKED source; incidence per §arch-6). The one-slot defer memo already covers csharp (preParse hoist listed it from day one).
• MAX_FILE_SIZE + generated-file skips: shared/orchestrator-side; nothing csharp-specific (isGeneratedFile gates fn-ref flush + value refs — mirror the calls, the patterns live in textutil.rs).
• Node-ID collisions: compare ID strings in fn-ref/value-ref self-checks (node_ids vec pattern — java.rs already does this).

Gates (per plan §5, no exceptions)

• Torture fixture Torture.cs (+ CRLF variant derived in-memory, normalization-proof) pinning at minimum: block namespace + file-scoped namespace file + two-namespaces-in-one-file (second nests under first) + nested namespace (inner leaves no trace); class with base_list (identifier + generic_name + qualified_name), attributes (NO decorates), /// docstring incl. doc-over-attribute; record class / record struct / readonly record struct (+ positional params → primary-ctor type refs) / bodiless record Empty; (node) / record UserDto(…) : BaseDto(Name), IThing (extends BaseDto(Name) full-text quirk); C#12 class primary ctor with base args (extends Base + (repo) + IThing quirk); bodiless struct Fwd; (NO node); interface with bodyless method + property + default-impl arrow method; enum with : byte (extends byte quirk), attributed member, valued members; const + static-readonly (→ constant)
  • multi-declarator + instance fields (signatures Type name); protected internal (→ protected); property shapes: predefined-type, bare-identifier type (signature loses type), generic type, expression-bodied (=> calls LOST), { get; } = new();, accessor bodies with calls (LOST); event_field_declaration + event_declaration with add/remove bodies (no nodes; accessor calls → class); operator + conversion operator + indexer + destructor (no nodes; body calls → class); constructor with : base(Compute()) (initializer calls LOST) + expression-bodied ctor (walked); explicit interface impl (Dispose bare name); local function (no node, calls → enclosing method); calls: bare, generic (Generic<int> verbatim), this.Run/base.Method (prefixes kept), _repo.Save, multi-line fluent chain (raw newlines), literal receiver ("lit".ToUpper emitted), ?. (raw request?.Method), p!.Force, chained Foo.Create(1).Bar() (re-encode + inner both) + GetThing().Bar(), (myDel)(x) (conv regex → myDel), nameof(Widget) (calls ref nameof); new Widget(…) { … } (instantiates + initializer calls) + new Ns.Foo<T>() (strip both) + new() / new { } / new Widget[10] (all NOTHING); static value reads (ReadType.ReadAsDouble → ReadType; Outer.Inner.DEEP → Outer; skip-as-callee; lowercase skip); type refs: params (nullable/array/tuple-element/generic/qualified/dynamic), returns (Task<List<Foo>> → refs Task+List+Foo but returnType undefined), suppressed builtins (String, int); where T : IEntity (NO refs); using forms: plain/dotted/static/global/alias-to-qualified (generic-args moduleName)/alias-to-identifier (alias-name quirk) + using inside namespace (refs from namespace node); top-level-statements file: var x = F(); (NOTHING), expression-statement calls (caller = file), top-level local function + trailing partial class Program; fn-refs: Register(HandleThing), Register(this.HandleThing) (bare name), Register(C.StaticHandler) (nothing), Click += OnClick, initializer_expression list, varinit (Action g = () => … no candidate; Del d = Handler; candidate), this.x = x param-storage skip; value-refs: const target + reader methods + a var MaxItems = … local shadow (prune) + static readonly multi-target; preprocessor: #region/#endregion/#pragma/#nullable/#define interleaved in class + enum bodies (parse-through, no emissions), and the #if/#else/#endif-in-enum shape as the DEFER fixture pre-blank — plus an intentionally-erroring file (e.g. an unclosed brace or the both-branches-kept interface shape) asserting the defer: signal; LINQ query + interpolated/raw/verbatim strings + switch expression + collection expressions (calls inside all reach the graph).
• Parity sweeps (scripts/kernel-parity.mjs, ORDER-sensitive full-object): serilog (small), Newtonsoft.Json (medium), jellyfin (large) — survey clones live at /private/tmp/claude-501/-Users-colby-Development-CodeGraph-codegraph/765a9532-0a92-43de-8d50-7c8ca1cb345c/scratchpad/{serilog,Newtonsoft.Json,jellyfin} (re-clone fresh if gone). Expected deferrals per §arch-6 (2.31% / 3.28% / 0.05%) — default --max-deferral 0.1, NO c/cpp 0.5 exemption; a double-digit rate means a broken walker, not grammar reality. Then full-init dump-diffs byte-identical (kernel arm vs CODEGRAPH_KERNEL=0, scripts/dump-graph.mjs, cmp) on the same three. jellyfin is an ASP.NET detect() hit — its per-file path is decoded either way (§arch-2); the dump gate is arm-vs-arm and unaffected.
• Suite: new __tests__/kernel-csharp-parity.test.ts (torture + CRLF + defer fixtures, strict full-object compare, CODEGRAPH_KERNEL_EXPECT=1 aware); add the csharp row to __tests__/kernel-grammar-parity.test.ts (crate tree_sitter_c_sharp::LANGUAGE vs vendored wasm, id-by-id); existing pinned behavior lives in __tests__/extraction.test.ts (describe blocks at 1342 C# Extraction, 2548 C# imports, 8924 C# records) and __tests__/resolution.test.ts — full suite green ×2 with CODEGRAPH_KERNEL_EXPECT=1.
• DEFAULT_ROUTED += csharp (src/extraction/kernel/index.ts:37) only after ALL of the above; changelog rides the existing kernel entry.
• Post-route perf sanity: §arch-2 — measure library repos (serilog/ Newtonsoft.Json) for the raw-buffer win; ASP.NET repos take the decoded path by design.

Fixtures to build (inventory)

1. __tests__/fixtures/kernel-parity/Torture.cs — the full pin list above (one file is fine; keep the two-namespace case in it).
2. TortureFileScoped.cs — file-scoped namespace + records + primary ctors + top-level using alias quirks (a file-scoped-ns file cannot host top-level statements — keep those separate).
3. TortureTopLevel.cs — top-level statements program (global statements, local function, trailing type decl).
4. CRLF variants of all three — derived in-memory in the test (the kernel-tsjs-parity pattern), never checked in as CRLF bytes.
5. TortureDefer.cs — the #if-in-enum ERROR shape with blanking DISABLED in the test arm… no: blanking is hoisted and always on — instead use a both-branches-kept interface shape (the serilog ILogger class) or a truly malformed tail that still errors POST-blank, asserting kernel defer: + wasm-fallback byte-parity through extractFromSource.
6. In-memory micro-fixtures inside the parity test for: the alias-import moduleName quirks, the (repo) extends quirk, the enum : byte quirk, nameof calls ref, this./base. callee prefixes, and the property-signature bare-identifier-type loss — cheap unit pins that make a future grammar bump scream early.