typescript: type receivers from a generic signature's T and from Record/index-signature elements

graph/test/typescript/cases/80-generic-return-receiver/lib/container.ts

@@ -0,0 +1,17 @@
+// A dependency-injection container as a library ships it: the service's type is
+// the call's own type argument, and nothing else names it.
+export class Container {
+  get<T>(id: symbol): T {
+    return undefined as unknown as T;
+  }
+  bind<T>(id: symbol): Container {
+    return this;
+  }
+}
+
+// A generic keyed store, the library-side twin of Map.
+export class Registry<V> {
+  lookup(key: string): V | undefined {
+    return undefined;
+  }
+}

graph/test/typescript/cases/80-generic-return-receiver/src/use.ts

@@ -0,0 +1,88 @@
+// A receiver whose type is what a GENERIC or computed call returns. Each shape is
+// statically typed by the compiler, so each `.m()` below has one declared target.
+
+export interface Warrior { fight(): string; }
+export class Ninja implements Warrior { fight(): string { return "ninja"; } }
+
+export class User {
+  touch(): string { return "t"; }
+  save(): string { return "s"; }
+}
+
+export interface Shape { area(): number; }
+export class Sq implements Shape { constructor(private s: number) {} area(): number { return this.s * this.s; } }
+export class Circ implements Shape { constructor(private r: number) {} area(): number { return 3 * this.r * this.r; } }
+
+// ── the gap ──────────────────────────────────────────────────────────────────
+// `Map<string, User>` built with `new`, read with `.get(k)!`.
+export function recvMapGet(): string {
+  const m = new Map<string, User>();
+  return m.get("x")!.touch();
+}
+
+// A function-typed PARAMETER with its own type parameter, called with a written argument.
+export function recvGeneric(get: <T>() => T): string {
+  return get<User>().touch();
+}
+
+// An index-signature object whose values are factories; the element is CALLED.
+const factories: { [k: string]: (n: number) => Shape } = {
+  sq: (n) => new Sq(n),
+  circ: (n) => new Circ(n),
+};
+export function totalArea(kind: string, n: number): number {
+  return factories[kind](n).area();
+}
+
+// The same through a declared Record alias.
+const makers: Record<string, (n: number) => Shape> = { sq: (n) => new Sq(n) };
+export function recordArea(kind: string, n: number): number {
+  return makers[kind](n).area();
+}
+
+// An inline index signature whose value is NOT a function: the element is a Shape.
+const shapes: { [k: string]: Shape } = { sq: new Sq(1) };
+export function indexValue(kind: string): number {
+  return shapes[kind].area();
+}
+
+// T bound from the ARGUMENT of a generic function-typed parameter.
+export function recvGenericArg(pick: <T>(x: T) => T, u: User): string {
+  return pick(u).save();
+}
+
+// ── controls: already typed, must not change ────────────────────────────────
+export function ctlDeclared(): string {
+  const u: User = JSON.parse("{}");
+  return u.save();
+}
+export function ctlCast(): string {
+  const u = JSON.parse("{}") as User;
+  return u.save();
+}
+// ── controls: nothing names the type, so these must STAY unresolved ─────────
+// The written type argument is `any`: T is untyped, and `.touch()` is a name only.
+export function ctlGenericUnbound(get: <T>() => T): string {
+  return get<any>().touch();
+}
+// An index signature over `any`: the element is untyped.
+const anyBag: { [k: string]: any } = {};
+export function ctlAnyIndex(kind: string): number {
+  return anyBag[kind].area();
+}
+
+// ── client -> library ────────────────────────────────────────────────────────
+import { Container, Registry } from "../lib/container";
+
+const container = new Container();
+const WARRIOR = Symbol.for("Warrior");
+container.bind<Warrior>(WARRIOR);
+
+export function run(): string {
+  const w = container.get<Warrior>(WARRIOR);
+  return w.fight();
+}
+
+export function viaRegistry(r: Registry<User>): string {
+  return r.lookup("x")!.touch();
+}

graph/test/typescript/expected/13-receiver-forms.edges

@@ -20,6 +20,7 @@ known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L22 -> Node#vis
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L23 -> Holder#make()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L23 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L24 -> Node#visit()
+known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L25 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L26 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L27 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L28 -> Node#visit()

graph/test/typescript/expected/13-receiver-forms.lib.edges

@@ -21,6 +21,7 @@ known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L22 -> Node#vis
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L23 -> Holder#make()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L23 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L24 -> Node#visit()
+known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L25 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L26 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L27 -> Node#visit()
 known_edge	METHOD_CALL	receivers#drive(Holder,Node | undefined) @L28 -> Node#visit()

graph/test/typescript/expected/73-assigned-interface-members.type-use

@@ -1,4 +1,3 @@
-ambiguous_unknown	METHOD_PARAM	1	Parse [TYPE] -> -
 known_edge	FIELD_TYPE	0	Schema [FIELD] -> Internals
 known_edge	METHOD_PARAM	0	schema [METHOD_PARAM] -> Schema
 known_edge	METHOD_TYPE_PARAM_BOUND	0	- [TYPE_PARAMETER] -> Schema

graph/test/typescript/expected/73-assigned-interface-members.types-oracle

@@ -1,8 +1,8 @@
 73-assigned-interface-members [types]
   precision 1.0000   (3 correct, 0 wrong)
   recall    0.7500   (3 of 4 the compiler resolved)
-  sites 6   resolved 5 (83.3%)
-  tiers ambiguous_unknown=1  known_edge=5
-  contexts FIELD_TYPE=1  METHOD_PARAM=3  METHOD_TYPE_PARAM_BOUND=1  VARIABLE_TYPE=1
-  not scored: 2 rows whose target is not a client declaration
+  sites 5   resolved 5 (100.0%)
+  tiers known_edge=5
+  contexts FIELD_TYPE=1  METHOD_PARAM=2  METHOD_TYPE_PARAM_BOUND=1  VARIABLE_TYPE=1
+  not scored: 1 rows whose target is not a client declaration
     MISSING Parse USES Schema

graph/test/typescript/expected/79-function-typed-parameter-dispatch.type-use

@@ -1,5 +1,4 @@
 ambiguous_unknown	AS_TARGET	0	store [EXPRESSION] -> -
-ambiguous_unknown	TYPE_ARGUMENT	2	LoggerImpl [TYPE] -> -
 ambiguous_unknown	TYPE_ELEMENT	1	store [METHOD_PARAM] -> -
 known_edge	CONDITIONAL_TRUE	2	Mutate [TYPE] -> Mutate
 known_edge	FIELD_TYPE	0	StoreApi [FIELD] -> SetStateInternal

graph/test/typescript/expected/79-function-typed-parameter-dispatch.types-oracle

@@ -1,7 +1,7 @@
 79-function-typed-parameter-dispatch [types]
   precision 1.0000   (12 correct, 0 wrong)
   recall    1.0000   (12 of 12 the compiler resolved)
-  sites 32   resolved 27 (84.4%)
-  tiers ambiguous_unknown=5  known_edge=27
-  contexts AS_TARGET=1  CONDITIONAL_TRUE=1  FIELD_TYPE=1  METHOD_PARAM=6  METHOD_RETURN=2  TYPE_ARGUMENT=8  TYPE_ELEMENT=11  VARIABLE_TYPE=2
-  not scored: 5 rows whose target is not a client declaration
+  sites 30   resolved 27 (90.0%)
+  tiers ambiguous_unknown=3  known_edge=27
+  contexts AS_TARGET=1  CONDITIONAL_TRUE=1  FIELD_TYPE=1  METHOD_PARAM=6  METHOD_RETURN=2  TYPE_ARGUMENT=6  TYPE_ELEMENT=11  VARIABLE_TYPE=2
+  not scored: 3 rows whose target is not a client declaration

graph/test/typescript/expected/80-generic-return-receiver.edges

@@ -0,0 +1,34 @@
+ambiguous_unknown	CONSTRUCTOR_CALL	use#<module-init>() @L77 -> -
+ambiguous_unknown	CONSTRUCTOR_CALL	use#recvMapGet() @L19 -> -
+ambiguous_unknown	METHOD_CALL	use#<module-init>() @L78 -> -
+ambiguous_unknown	METHOD_CALL	use#<module-init>() @L79 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlAnyIndex(string) @L71 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlCast() @L60 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlDeclared() @L56 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlGenericUnbound(() =) @L66 -> -
+ambiguous_unknown	METHOD_CALL	use#recvMapGet() @L20 -> -
+ambiguous_unknown	METHOD_CALL	use#run() @L82 -> -
+ambiguous_unknown	METHOD_CALL	use#run() @L83 -> -
+ambiguous_unknown	METHOD_CALL	use#viaRegistry(Registry) @L87 -> -
+known_edge	CONSTRUCTOR_CALL	use#<arrow@30>(?) @L30 -> Sq#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<arrow@31>(?) @L31 -> Circ#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<arrow@38>(?) @L38 -> Sq#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<module-init>() @L44 -> Sq#<new>(number)
+known_edge	FUNCTION_CALL	use#ctlGenericUnbound(() =) @L66 -> use#<arrow@65>()
+known_edge	FUNCTION_CALL	use#recvGeneric(() =) @L25 -> use#<arrow@24>()
+known_edge	FUNCTION_CALL	use#recvGenericArg((x: T) =,User) @L51 -> use#<arrow@50>(T)
+known_edge	METHOD_CALL	use#ctlCast() @L61 -> User#save()
+known_edge	METHOD_CALL	use#ctlDeclared() @L57 -> User#save()
+known_edge	METHOD_CALL	use#recordArea(string,number) @L40 -> use#<arrow@38>(number)
+known_edge	METHOD_CALL	use#recvGeneric(() =) @L25 -> User#touch()
+known_edge	METHOD_CALL	use#recvGenericArg((x: T) =,User) @L51 -> User#save()
+known_edge	METHOD_CALL	use#totalArea(string,number) @L34 -> use#<arrow@29>(number)
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Circ#area()
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Shape#area()
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Sq#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Circ#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Shape#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Sq#area()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Circ#area()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Shape#area()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Sq#area()

graph/test/typescript/expected/80-generic-return-receiver.entries

@@ -0,0 +1,14 @@
+── entry_point (13) ──
+  exported_from_entry_module use#ctlAnyIndex   use.ts:70
+  exported_from_entry_module use#ctlCast   use.ts:59
+  exported_from_entry_module use#ctlDeclared   use.ts:55
+  exported_from_entry_module use#ctlGenericUnbound   use.ts:65
+  exported_from_entry_module use#indexValue   use.ts:45
+  exported_from_entry_module use#recordArea   use.ts:39
+  exported_from_entry_module use#recvGeneric   use.ts:24
+  exported_from_entry_module use#recvGenericArg   use.ts:50
+  exported_from_entry_module use#recvMapGet   use.ts:18
+  exported_from_entry_module use#run   use.ts:81
+  exported_from_entry_module use#totalArea   use.ts:33
+  exported_from_entry_module use#viaRegistry   use.ts:86
+  unimported_module use#<module>   use.ts:1

graph/test/typescript/expected/80-generic-return-receiver.envelope

@@ -0,0 +1,6 @@
+nominal	use#Shape.area -> use#Circ.area
+nominal	use#Shape.area -> use#Sq.area
+nominal	use#Warrior.fight -> use#Ninja.fight
+value_call	use#recordArea -> use#<arrow>@38
+value_call	use#totalArea -> use#<arrow>@30
+value_call	use#totalArea -> use#<arrow>@31

graph/test/typescript/expected/80-generic-return-receiver.fields

@@ -0,0 +1,2 @@
+known_edge	read	Circ#area() -> Circ#r
+known_edge	read	Sq#area() -> Sq#s

graph/test/typescript/expected/80-generic-return-receiver.fields-oracle

@@ -0,0 +1,7 @@
+80-generic-return-receiver [fields]
+  precision 1.0000   (2 correct, 0 wrong)
+  recall    1.0000   (2 of 2 the compiler resolved)
+  sites 4   resolved 4 (100.0%)
+  tiers known_edge=4
+  access read=4
+  not scored: 0 rows whose target is not a client declaration

graph/test/typescript/expected/80-generic-return-receiver.known-missing

@@ -0,0 +1,10 @@
+# Accepted gaps for 80-generic-return-receiver — each line is an edge the TypeScript compiler
+# resolves and this engine does not. A NEW missing edge fails the suite;
+# a line here that STARTS working also fails, so the debt cannot rot.
+# The receiver's type is the return of a LIBRARY generic: with no library there is no
+# signature to read it from. run and viaRegistry resolve in the .lib pass.
+use#run() -> Warrior#fight()
+use#viaRegistry(Registry) -> User#touch()
+# `Map` is the standard library's, which no case pass loads; it resolves on a real index
+# given the TypeScript lib as a library.
+use#recvMapGet() -> User#touch()

graph/test/typescript/expected/80-generic-return-receiver.lib.edges

@@ -0,0 +1,36 @@
+ambiguous_unknown	CONSTRUCTOR_CALL	use#recvMapGet() @L19 -> -
+ambiguous_unknown	METHOD_CALL	use#<module-init>() @L78 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlAnyIndex(string) @L71 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlCast() @L60 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlDeclared() @L56 -> -
+ambiguous_unknown	METHOD_CALL	use#ctlGenericUnbound(() =) @L66 -> -
+ambiguous_unknown	METHOD_CALL	use#recvMapGet() @L20 -> -
+boundary_lib	CONSTRUCTOR_CALL	use#<module-init>() @L77 -> Container#<new>()
+boundary_lib	METHOD_CALL	use#<module-init>() @L79 -> Container#bind(symbol)
+boundary_lib	METHOD_CALL	use#run() @L82 -> Container#get(symbol)
+boundary_lib	METHOD_CALL	use#viaRegistry(Registry) @L87 -> Registry#lookup(string)
+known_edge	CONSTRUCTOR_CALL	use#<arrow@30>(?) @L30 -> Sq#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<arrow@31>(?) @L31 -> Circ#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<arrow@38>(?) @L38 -> Sq#<new>(number)
+known_edge	CONSTRUCTOR_CALL	use#<module-init>() @L44 -> Sq#<new>(number)
+known_edge	FUNCTION_CALL	use#ctlGenericUnbound(() =) @L66 -> use#<arrow@65>()
+known_edge	FUNCTION_CALL	use#recvGeneric(() =) @L25 -> use#<arrow@24>()
+known_edge	FUNCTION_CALL	use#recvGenericArg((x: T) =,User) @L51 -> use#<arrow@50>(T)
+known_edge	METHOD_CALL	use#ctlCast() @L61 -> User#save()
+known_edge	METHOD_CALL	use#ctlDeclared() @L57 -> User#save()
+known_edge	METHOD_CALL	use#recordArea(string,number) @L40 -> use#<arrow@38>(number)
+known_edge	METHOD_CALL	use#recvGeneric(() =) @L25 -> User#touch()
+known_edge	METHOD_CALL	use#recvGenericArg((x: T) =,User) @L51 -> User#save()
+known_edge	METHOD_CALL	use#totalArea(string,number) @L34 -> use#<arrow@29>(number)
+known_edge	METHOD_CALL	use#viaRegistry(Registry) @L87 -> User#touch()
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Circ#area()
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Shape#area()
+multi_inferred	METHOD_CALL	use#indexValue(string) @L46 -> Sq#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Circ#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Shape#area()
+multi_inferred	METHOD_CALL	use#recordArea(string,number) @L40 -> Sq#area()
+multi_inferred	METHOD_CALL	use#run() @L83 -> Ninja#fight()
+multi_inferred	METHOD_CALL	use#run() @L83 -> Warrior#fight()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Circ#area()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Shape#area()
+multi_inferred	METHOD_CALL	use#totalArea(string,number) @L34 -> Sq#area()

graph/test/typescript/expected/80-generic-return-receiver.lib.envelope

@@ -0,0 +1,6 @@
+nominal	use#Shape.area -> use#Circ.area
+nominal	use#Shape.area -> use#Sq.area
+nominal	use#Warrior.fight -> use#Ninja.fight
+value_call	use#recordArea -> use#<arrow>@38
+value_call	use#totalArea -> use#<arrow>@30
+value_call	use#totalArea -> use#<arrow>@31

graph/test/typescript/expected/80-generic-return-receiver.lib.known-missing

@@ -0,0 +1,6 @@
+# Accepted gaps for 80-generic-return-receiver — each line is an edge the TypeScript compiler
+# resolves and this engine does not. A NEW missing edge fails the suite;
+# a line here that STARTS working also fails, so the debt cannot rot.
+# `Map` is the standard library's, which no case pass loads; it resolves on a real index
+# given the TypeScript lib as a library.
+use#recvMapGet() -> User#touch()

graph/test/typescript/expected/80-generic-return-receiver.lib.oracle

@@ -0,0 +1,9 @@
+oracle=23 engine=29 agree=22 missing=1 (known 1, NEW 0) extra=7
+  known    use#recvMapGet() -> User#touch()
+  extra    use#indexValue(string) -> Circ#area()
+  extra    use#indexValue(string) -> Sq#area()
+  extra    use#recordArea(string,number) -> Circ#area()
+  extra    use#recordArea(string,number) -> Sq#area()
+  extra    use#run() -> Ninja#fight()
+  extra    use#totalArea(string,number) -> Circ#area()
+  extra    use#totalArea(string,number) -> Sq#area()

graph/test/typescript/expected/80-generic-return-receiver.oracle

@@ -0,0 +1,10 @@
+oracle=19 engine=22 agree=16 missing=3 (known 3, NEW 0) extra=6
+  known    use#recvMapGet() -> User#touch()
+  known    use#run() -> Warrior#fight()
+  known    use#viaRegistry(Registry) -> User#touch()
+  extra    use#indexValue(string) -> Circ#area()
+  extra    use#indexValue(string) -> Sq#area()
+  extra    use#recordArea(string,number) -> Circ#area()
+  extra    use#recordArea(string,number) -> Sq#area()
+  extra    use#totalArea(string,number) -> Circ#area()
+  extra    use#totalArea(string,number) -> Sq#area()

graph/test/typescript/expected/80-generic-return-receiver.type-use

@@ -0,0 +1,16 @@
+ambiguous_unknown	METHOD_PARAM	0	use [METHOD_PARAM] -> -
+ambiguous_unknown	OBJECT_CREATION_TYPE	0	use [EXPRESSION] -> -
+ambiguous_unknown	VARIABLE_TYPE	0	use [VARIABLE] -> -
+known_edge	AS_TARGET	0	use [EXPRESSION] -> User
+known_edge	IMPLEMENTS_INTERFACE	0	Circ [HERITAGE] -> Shape
+known_edge	IMPLEMENTS_INTERFACE	0	Ninja [HERITAGE] -> Warrior
+known_edge	IMPLEMENTS_INTERFACE	0	Sq [HERITAGE] -> Shape
+known_edge	INDEX_SIGNATURE_VALUE	1	use [VARIABLE] -> Shape
+known_edge	METHOD_PARAM	0	use [METHOD_PARAM] -> User
+known_edge	METHOD_RETURN	2	use [VARIABLE] -> Shape
+known_edge	METHOD_TYPE_ARGUMENT	0	use [EXPRESSION] -> User
+known_edge	METHOD_TYPE_ARGUMENT	0	use [EXPRESSION] -> Warrior
+known_edge	OBJECT_CREATION_TYPE	0	use [EXPRESSION] -> Circ
+known_edge	OBJECT_CREATION_TYPE	0	use [EXPRESSION] -> Sq
+known_edge	TYPE_ARGUMENT	1	use [METHOD_PARAM] -> User
+known_edge	VARIABLE_TYPE	0	use [VARIABLE] -> User

graph/test/typescript/expected/80-generic-return-receiver.types-oracle

@@ -0,0 +1,7 @@
+80-generic-return-receiver [types]
+  precision 1.0000   (8 correct, 0 wrong)
+  recall    1.0000   (8 of 8 the compiler resolved)
+  sites 22   resolved 18 (81.8%)
+  tiers ambiguous_unknown=4  known_edge=18
+  contexts AS_TARGET=1  IMPLEMENTS_INTERFACE=3  INDEX_SIGNATURE_VALUE=1  METHOD_PARAM=2  METHOD_RETURN=2  METHOD_TYPE_ARGUMENT=4  OBJECT_CREATION_TYPE=6  TYPE_ARGUMENT=1  VARIABLE_TYPE=2
+  not scored: 4 rows whose target is not a client declaration

graph/typescript/engine/expression-resolution/expr-type.dl

@@ -601,6 +601,20 @@ expr_element_type(e, prov, t) :- expr_type(e, _, qt),
 expr_element_type(e, prov, t) :- expr_type(e, _, qt),
     index_signature_in_scope(qt, f),
     field_type(f, prov, t).
+// …and the same signature written INLINE — `const reg: { [k: string]: Handler }` —
+// where the qualifier has a SHAPE rather than a named type. And where the signature's
+// value is itself a function type, `{ [k: string]: (n: number) => Shape }`, the element
+// is that signature: `factories[kind](n).area()` is a call on it, and without the shape
+// the call had no candidate and `.area()` no receiver type.
+expr_element_type(e, prov, t) :- expr_shape(e, qs),
+    index_signature_in_scope(qs, f),
+    field_type(f, prov, t).
+expr_element_shape(e, sh) :- expr_type(e, _, qt),
+    index_signature_in_scope(qt, f),
+    field_shape(f, sh).
+expr_element_shape(e, sh) :- expr_shape(e, qs),
+    index_signature_in_scope(qs, f),
+    field_shape(f, sh).
 
 // ── `new C()` — the constructed type ───────────────────────────────────────
 expr_type(e, prov, t) :- expr_kind("client", "NEW_EXPRESSION", _, e),

graph/typescript/engine/resolution/type-resolution.dl

@@ -615,6 +615,15 @@ ref_element_target(ref, prov, t) :- type_ref(rp, "TYPE_REFERENCE", _, tn, _, _,
     ref_name_is_container(tn),
     type_ref_parent(rp, ref, "0", child),
     ref_type_target(child, prov, t).
+// `Record<K, V>` read by key — `makers[kind](n)` — yields V, which is type argument 1,
+// not 0, so it is kept off the container list: iterating a Record does not compile, and
+// the list's promise is argument 0.
+ref_element_target(ref, prov, t) :- type_ref(rp, "TYPE_REFERENCE", _, "Record", _, _, _, ref),
+    type_ref_parent(rp, ref, "1", child),
+    ref_type_target(child, prov, t).
+ref_element_shape(ref, sh) :- type_ref(rp, "TYPE_REFERENCE", _, "Record", _, _, _, ref),
+    type_ref_parent(rp, ref, "1", child),
+    ref_shape_target(child, sh).
 ref_name_is_container("Array").
 ref_name_is_container("ReadonlyArray").
 ref_name_is_container("Iterable").