diff --git a/graph/javascript/engine/call-edge-generation/calls.dl b/graph/javascript/engine/call-edge-generation/calls.dl
index 39dbe789..5745b29d 100644
--- a/graph/javascript/engine/call-edge-generation/calls.dl
+++ b/graph/javascript/engine/call-edge-generation/calls.dl
@@ -170,6 +170,29 @@ call_chain_edge(ce, caller, "-", m, "client", "multi_inferred", kind) :-
     wrapper_call_target(ce, m), !call_over_cap(ce), call_from(ce, caller), invocation_site(ce, kind).
 variable_reassigned(v) :- expr_kind(_, "ASSIGNMENT", _, a), expr_child(_, a, "ASSIGNMENT_TARGET", _, tgt),
     expr_binding(_, v, tgt).
+// ── a call of what a PROJECT wrapper returned runs what that site was handed ──
+// `export default promisable(eachItem, 3)`, `const add = curry2(function add(a, b) {…})`:
+// the wrapper returns a closure that calls its parameter, and every export of the module
+// is that closure. The closure's call of the parameter is read context-insensitively, so
+// it held every function any of the wrapper's sites passed (past the fan cap: nothing),
+// and a test calling the export reached the closure and stopped there. The site is
+// already a value of its own, ("wrap", site), beside the closure (value-flow.dl), and a
+// call through it takes its RESULT from that site's argument alone; the same site says
+// what the call RUNS: the function it was handed at the forwarded position, what the
+// wrapper writes into that parameter, or what a wrapped argument itself runs
+// (`memoize(once(f))`). One of a set, beside the edge to the closure the call keeps, and
+// under the same fan cap: a callee that may hold more wrapped values than --dispatch-cap
+// (a parameter every wrapped export is passed to) runs one of them, and naming all of
+// them says nothing.
+wrap_runs(s, g) :- wrap_site_arg(s, _, arg), expr_value(arg, "func", g).
+wrap_runs(s, g) :- wrap_site_arg(s, _, arg), expr_value(arg, "wrap", s2), wrap_runs(s2, g).
+wrap_runs(s, g) :- wrap_site(s, h, pos), wrapper_param_written(h, pos, o), expr_value(o, "func", g).
+wrapped_call_target(ce, g) :- callee_value(ce, "wrap", s), wrap_runs(s, g), method_prov(g, "client"),
+    !call_site(_, "FUNCTION_CALL_BIND", _, _, _, _, ce, _, _).
+wrapped_target_count(ce, n) :- wrapped_call_target(ce, _), n = count : { wrapped_call_target(ce, _) }.
+wrapped_over_cap(ce) :- wrapped_target_count(ce, n), dispatch_cap(c), n > to_number(c).
+call_chain_edge(ce, caller, "-", g, "client", "multi_inferred", kind) :-
+    wrapped_call_target(ce, g), !call_over_cap(ce), !wrapped_over_cap(ce), call_from(ce, caller), invocation_site(ce, kind).
 // `(c ? a : b)()`, `(0, cb)()`, `make()()`: the callee is computed by an expression.
 // `new Function(s)()` / `Function(s)()` runs code built at run time.
 unresolved_value_callee(ce, "dynamic_code") :- value_callee_unresolved(ce, c), callee_builds_code(c).
diff --git a/graph/javascript/engine/resolution/fan-cap.dl b/graph/javascript/engine/resolution/fan-cap.dl
index af6bdd93..ad69acdb 100644
--- a/graph/javascript/engine/resolution/fan-cap.dl
+++ b/graph/javascript/engine/resolution/fan-cap.dl
@@ -80,14 +80,48 @@ direct_export_func(mod, n, m) :- export_decl(_, n, _, _, _, _, _, se, mod, _), s
 // shares its name with hundreds of unrelated sites and must not be capped by them,
 // while a module-level `each` or `merge` called under its own name from everywhere
 // is exactly the generic utility the cap exists for.
+//
+// The PROGRAM's arguments are decided by the program's sites alone. A suite calls the
+// API it tests over and over, and counted with the program those calls made exactly the
+// functions under test "generic utilities": their parameters went untracked, so a
+// callback the program hands a constructor and stores on the instance (`this.decode =
+// options.decode`) was lost, and the program's own call through that field resolved only
+// to the fallback beside it. So there are two verdicts:
+//   method_is_hot             every site counts (as before): decides whether a TEST's
+//                             arguments flow in
+//   method_is_hot_in_program  test files' sites do not count: decides whether the
+//                             PROGRAM's arguments flow in
+// Nothing that flowed before stops flowing (a test handing the program a plugin it calls
+// back still reaches it). A function hot only because of its tests now receives what the
+// program passes it and still nothing from the tests: their callbacks would be the widest
+// values it holds, and with them the call through the stored field would be over the
+// dispatch cap and answer nothing.
 param_flow_capped_at(n) :- dispatch_cap(s), n = to_number(s).
 direct_call_count(m, n) :- direct_call_site(_, m), n = count : { direct_call_site(_, m) }.
 method_is_hot(m, n) :- direct_call_count(m, n), param_flow_capped_at(c), n > c.
 name_call_count(cn, n) :- call_site(_, _, cn, _, _, _, _, _, _), cn != "", n = count : { call_site(_, _, cn, _, _, _, _, _, _) }.
+program_direct_site(ce, m) :- direct_call_site(ce, m), !site_in_test_module(ce).
+program_direct_count(m, n) :- program_direct_site(_, m), n = count : { program_direct_site(_, m) }.
+method_is_hot_in_program(m, n) :- program_direct_count(m, n), param_flow_capped_at(c), n > c.
+// The NAME count is the overcount for module-level functions. A test's member call that
+// only shares the name (`lib.add(1, 2)` on an export that is a different function, a
+// curried closure) stays in it, as before; a test's bare call or `new` of the name
+// (`build(...)`, `new lib.Codec(...)`) denotes the function itself and leaves it.
+test_names_itself(ce) :- site_in_test_module(ce), call_site(_, ck, _, _, _, _, ce, _, _), call_kind_is_callee_form(ck).
+test_names_itself(ce) :- site_in_test_module(ce), call_site(_, "CONSTRUCTOR_CALL", _, _, _, _, ce, _, _).
+program_name_site(m, ce) :- module_level_function(m, cn), call_site(_, _, cn, _, _, _, ce, _, _), !test_names_itself(ce).
+program_name_count(m, n) :- program_name_site(m, _), n = count : { program_name_site(m, _) }.
+// ── test_module / site_in_test_module ──────────────
+// By path, as runners find their files: a `test`/`tests`/`__tests__`/`spec(s)` directory,
+// or a `.test.` / `.spec.` file.
+test_module(mod) :- module_file("client", fp, mod),
+    match("(.*/)?(tests?|__tests__|specs?)/.*|.*[.](test|spec)[.][cm]?[jt]sx?", fp).
+site_in_test_module(ce) :- expr_owner(_, _, mod, ce), test_module(mod).
 module_level_function(m, n) :- method_decl(_, n, "FUNCTION_DECLARATION", _, _, "", mod, m), method_scopes(_, _, _, init, m), module_init(_, init, mod).
 module_level_function(m, n) :- var_decl(_, n, _, _, _, mod, v), function_binding_value(v, m), method_decl(_, _, _, _, _, "", mod, m),
     method_scopes(_, _, _, init, m), module_init(_, init, mod).
 method_is_hot(m, n) :- module_level_function(m, cn), name_call_count(cn, n), param_flow_capped_at(c), n > c.
+method_is_hot_in_program(m, n) :- program_name_count(m, n), param_flow_capped_at(c), n > c.
 
 // ── param_fan_capped(ParamHash, SiteCount) — countable ──────────────────────
-param_fan_capped(p, n) :- method_is_hot(m, n), param_decl(_, _, _, m, p).
+param_fan_capped(p, n) :- method_is_hot_in_program(m, n), param_decl(_, _, _, m, p).
diff --git a/graph/javascript/engine/resolution/value-flow.dl b/graph/javascript/engine/resolution/value-flow.dl
index 2c79e52b..e78863e2 100644
--- a/graph/javascript/engine/resolution/value-flow.dl
+++ b/graph/javascript/engine/resolution/value-flow.dl
@@ -264,8 +264,15 @@ param_value(p, "inst", t) :- param_type_name(_, _, tr, p), type_ref_type(tr, t).
 // values on every export, a 20-minute solve — because a generic library is exactly
 // the shape whose parameters unify everything. What a library does with a callback it
 // is handed is a MODEL (resolution/frameworks.dl), stated per library, not inferred.
-param_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), !method_is_hot(m, _),
-    method_decl("client", _, _, _, _, _, _, m),
+// The program's sites pass their arguments unless the PROGRAM calls the function from
+// more places than the cap; a test file's sites only while every site together stays
+// under it (fan-cap.dl).
+param_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), !site_in_test_module(ce),
+    !method_is_hot_in_program(m, _), method_decl("client", _, _, _, _, _, _, m),
+    param_decl(_, _, ppos, m, p), to_number(ppos) = pos, !param_is_rest(_, p),
+    expr_value(arg, k, i).
+param_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), site_in_test_module(ce),
+    !method_is_hot(m, _), method_decl("client", _, _, _, _, _, _, m),
     param_decl(_, _, ppos, m, p), to_number(ppos) = pos, !param_is_rest(_, p),
     expr_value(arg, k, i).
 // THE ONE LIBRARY EXCEPTION: a UMD wrapper (#710). `(function (root, factory) {
@@ -283,8 +290,12 @@ param_value(p, "func", f) :- call_site(_, "IIFE_CALL", _, _, _, _, ce, _, _), ca
     expr_value(arg, "func", f).
 // A rest parameter IS an array; the arguments at and past its position are its elements.
 param_value(p, "arr", p) :- param_is_rest(_, p).
-elem_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), !method_is_hot(m, _),
-    method_decl("client", _, _, _, _, _, _, m),
+elem_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), !site_in_test_module(ce),
+    !method_is_hot_in_program(m, _), method_decl("client", _, _, _, _, _, _, m),
+    param_decl(_, _, ppos, m, p), param_is_rest(_, p), to_number(ppos) <= pos,
+    expr_value(arg, k, i).
+elem_value(p, k, i) :- call_arg(ce, pos, arg), expr_resolves_to_method(ce, m), site_in_test_module(ce),
+    !method_is_hot(m, _), method_decl("client", _, _, _, _, _, _, m),
     param_decl(_, _, ppos, m, p), param_is_rest(_, p), to_number(ppos) <= pos,
     expr_value(arg, k, i).
 // A default value: `cb = () => {}`. The parser gives the parameter the default's
diff --git a/graph/javascript/souffle/decls_all.dl b/graph/javascript/souffle/decls_all.dl
index b7b56647..bc489cb6 100644
--- a/graph/javascript/souffle/decls_all.dl
+++ b/graph/javascript/souffle/decls_all.dl
@@ -112,6 +112,10 @@
 .decl wrapper_holder_call(c0:symbol, c1:symbol)
 .decl wrapper_runs(c0:symbol, c1:symbol)
 .decl wrapper_call_target(c0:symbol, c1:symbol)
+.decl wrap_runs(c0:symbol, c1:symbol)
+.decl wrapped_call_target(c0:symbol, c1:symbol)
+.decl wrapped_target_count(c0:symbol, c1:number)
+.decl wrapped_over_cap(c0:symbol)
 .decl live_export_variable(c0:symbol, c1:symbol)
 .decl this_type_open(c0:symbol)
 
@@ -462,6 +466,14 @@
 .decl param_fan_capped(c0:symbol, c1:number)
 .decl import_binding_is_default_like(c0:symbol)
 .decl name_call_count(c0:symbol, c1:number)
+.decl test_module(c0:symbol)
+.decl site_in_test_module(c0:symbol)
+.decl program_direct_site(c0:symbol, c1:symbol)
+.decl program_direct_count(c0:symbol, c1:number)
+.decl method_is_hot_in_program(c0:symbol, c1:number)
+.decl test_names_itself(c0:symbol)
+.decl program_name_site(c0:symbol, c1:symbol)
+.decl program_name_count(c0:symbol, c1:number)
 .decl module_level_function(c0:symbol, c1:symbol)
 .decl ambient_collection(c0:symbol)
 .decl coll_method_call(c0:symbol, c1:symbol, c2:symbol)
diff --git a/graph/test/javascript/expected/64-memoize-wrapper-result.edges b/graph/test/javascript/expected/64-memoize-wrapper-result.edges
index c3d46e25..46a76a11 100644
--- a/graph/test/javascript/expected/64-memoize-wrapper-result.edges
+++ b/graph/test/javascript/expected/64-memoize-wrapper-result.edges
@@ -1,6 +1,8 @@
 app.js:11:3 FUNCTION_CALL getAlpha  ->  known_edge  memoize.js:5:10 <arrow>
+app.js:11:3 FUNCTION_CALL getAlpha  ->  multi_inferred  app.js:7:26 <arrow>
 app.js:11:3 METHOD_CALL getAlpha().getHooks  ->  known_edge  alpha.js:2:3 getHooks
 app.js:12:3 FUNCTION_CALL getBeta  ->  known_edge  memoize.js:5:10 <arrow>
+app.js:12:3 FUNCTION_CALL getBeta  ->  multi_inferred  app.js:8:25 <arrow>
 app.js:12:3 METHOD_CALL getBeta().getHooks  ->  known_edge  beta.js:2:3 getHooks
 app.js:16:20 FUNCTION_CALL once  ->  callback_registered  app.js:16:25 <arrow>
 app.js:16:20 FUNCTION_CALL once  ->  known_edge  once.js:2:1 once
@@ -15,12 +17,16 @@ app.js:19:19 FUNCTION_CALL lazy  ->  callback_registered  app.js:19:24 <arrow>
 app.js:19:19 FUNCTION_CALL lazy  ->  known_edge  once.js:14:1 lazy
 app.js:19:30 CONSTRUCTOR_CALL AlphaPlugin  ->  implicit_constructor  -
 app.js:22:3 FUNCTION_CALL firstAlpha  ->  known_edge  once.js:5:10 <function-expression>
+app.js:22:3 FUNCTION_CALL firstAlpha  ->  multi_inferred  app.js:16:25 <arrow>
 app.js:22:3 METHOD_CALL firstAlpha().run  ->  known_edge  alpha.js:3:3 run
 app.js:23:3 FUNCTION_CALL makeBeta  ->  known_edge  once.js:15:10 <arrow>
+app.js:23:3 FUNCTION_CALL makeBeta  ->  multi_inferred  app.js:17:23 <arrow>
 app.js:23:3 METHOD_CALL makeBeta().run  ->  known_edge  beta.js:3:3 run
 app.js:24:3 FUNCTION_CALL firstBeta  ->  known_edge  once.js:5:10 <function-expression>
+app.js:24:3 FUNCTION_CALL firstBeta  ->  multi_inferred  app.js:18:24 <arrow>
 app.js:24:3 METHOD_CALL firstBeta().run  ->  known_edge  beta.js:3:3 run
 app.js:25:3 FUNCTION_CALL makeAlpha  ->  known_edge  once.js:15:10 <arrow>
+app.js:25:3 FUNCTION_CALL makeAlpha  ->  multi_inferred  app.js:19:24 <arrow>
 app.js:25:3 METHOD_CALL makeAlpha().run  ->  known_edge  alpha.js:3:3 run
 app.js:29:18 FUNCTION_CALL constant  ->  known_edge  once.js:18:1 constant
 app.js:29:27 CONSTRUCTOR_CALL BetaPlugin  ->  implicit_constructor  -
@@ -57,10 +63,14 @@ declared.js:27:16 FUNCTION_CALL pickShared  ->  callback_registered  declared.js
 declared.js:27:16 FUNCTION_CALL pickShared  ->  known_edge  declared.js:20:1 pickShared
 declared.js:27:33 CONSTRUCTOR_CALL BetaPlugin  ->  implicit_constructor  -
 declared.js:30:3 FUNCTION_CALL declAlpha  ->  known_edge  declared.js:9:3 inner
+declared.js:30:3 FUNCTION_CALL declAlpha  ->  multi_inferred  declared.js:22:28 <arrow>
 declared.js:30:3 METHOD_CALL declAlpha().run  ->  known_edge  alpha.js:3:3 run
 declared.js:31:3 FUNCTION_CALL declBeta  ->  known_edge  declared.js:9:3 inner
+declared.js:31:3 FUNCTION_CALL declBeta  ->  multi_inferred  declared.js:23:27 <arrow>
 declared.js:31:3 METHOD_CALL declBeta().run  ->  known_edge  beta.js:3:3 run
 declared.js:32:3 FUNCTION_CALL declOfGetter  ->  known_edge  declared.js:9:3 inner
+declared.js:32:3 FUNCTION_CALL declOfGetter  ->  multi_inferred  declared.js:24:26 <arrow>
+declared.js:32:3 FUNCTION_CALL declOfGetter  ->  multi_inferred  memoize.js:5:10 <arrow>
 declared.js:32:3 METHOD_CALL declOfGetter().run  ->  known_edge  alpha.js:3:3 run
 declared.js:33:3 FUNCTION_CALL tappedDecl  ->  known_edge  declared.js:15:3 inner
 declared.js:33:3 METHOD_CALL tappedDecl().markOnly  ->  known_edge  declared.js:13:14 markOnly
@@ -202,24 +212,33 @@ shapes.js:45:27 FUNCTION_CALL memoize  ->  callback_registered  shapes.js:45:35
 shapes.js:45:27 FUNCTION_CALL memoize  ->  known_edge  memoize.js:2:17 <arrow>
 shapes.js:45:41 CONSTRUCTOR_CALL BetaPlugin  ->  implicit_constructor  -
 shapes.js:48:3 FUNCTION_CALL getFb  ->  known_edge  shapes.js:15:10 <arrow>
+shapes.js:48:3 FUNCTION_CALL getFb  ->  multi_inferred  shapes.js:36:28 <arrow>
 shapes.js:48:3 METHOD_CALL getFb().run  ->  known_edge  alpha.js:3:3 run
 shapes.js:49:3 FUNCTION_CALL getFb  ->  known_edge  shapes.js:15:10 <arrow>
+shapes.js:49:3 FUNCTION_CALL getFb  ->  multi_inferred  shapes.js:36:28 <arrow>
 shapes.js:49:3 METHOD_CALL getFb().fallbackOnly  ->  known_edge  shapes.js:8:18 fallbackOnly
 shapes.js:50:3 FUNCTION_CALL getOr  ->  known_edge  shapes.js:22:10 <arrow>
+shapes.js:50:3 FUNCTION_CALL getOr  ->  multi_inferred  shapes.js:38:22 <arrow>
 shapes.js:50:3 METHOD_CALL getOr().run  ->  ambient_terminal  -
 shapes.js:50:3 METHOD_CALL getOr().run  ->  multi_inferred  beta.js:3:3 run
 shapes.js:51:3 FUNCTION_CALL getOr  ->  known_edge  shapes.js:22:10 <arrow>
+shapes.js:51:3 FUNCTION_CALL getOr  ->  multi_inferred  shapes.js:38:22 <arrow>
 shapes.js:51:3 METHOD_CALL getOr().mockOnly  ->  ambient_terminal  -
 shapes.js:51:3 METHOD_CALL getOr().mockOnly  ->  multi_inferred  shapes.js:9:14 mockOnly
 shapes.js:52:3 FUNCTION_CALL getD  ->  known_edge  shapes.js:29:10 <arrow>
+shapes.js:52:3 FUNCTION_CALL getD  ->  multi_inferred  shapes.js:39:26 <arrow>
 shapes.js:52:3 METHOD_CALL getD().run  ->  known_edge  alpha.js:3:3 run
 shapes.js:53:3 FUNCTION_CALL getD  ->  known_edge  shapes.js:29:10 <arrow>
+shapes.js:53:3 FUNCTION_CALL getD  ->  multi_inferred  shapes.js:39:26 <arrow>
 shapes.js:53:3 METHOD_CALL getD().defaultsOnly  ->  known_edge  shapes.js:25:20 defaultsOnly
 shapes.js:54:3 FUNCTION_CALL getDefault  ->  known_edge  shapes.js:33:44 <arrow>
 shapes.js:54:3 METHOD_CALL getDefault().defaultOnly  ->  known_edge  shapes.js:10:19 defaultOnly
 shapes.js:55:3 FUNCTION_CALL getSpread  ->  known_edge  shapes.js:33:44 <arrow>
 shapes.js:55:3 METHOD_CALL getSpread().run  ->  ambiguous_unknown  -
 shapes.js:56:3 FUNCTION_CALL warm  ->  known_edge  shapes.js:34:32 <arrow>
+shapes.js:56:3 FUNCTION_CALL warm  ->  multi_inferred  shapes.js:43:20 <arrow>
 shapes.js:56:3 METHOD_CALL warm().run  ->  known_edge  alpha.js:3:3 run
 shapes.js:57:3 FUNCTION_CALL getNested  ->  known_edge  memoize.js:5:10 <arrow>
+shapes.js:57:3 FUNCTION_CALL getNested  ->  multi_inferred  memoize.js:5:10 <arrow>
+shapes.js:57:3 FUNCTION_CALL getNested  ->  multi_inferred  shapes.js:45:35 <arrow>
 shapes.js:57:3 METHOD_CALL getNested().run  ->  known_edge  beta.js:3:3 run
diff --git a/graph/test/javascript/expected/65-wrapper-param-reassigned.edges b/graph/test/javascript/expected/65-wrapper-param-reassigned.edges
index d56c695d..8373c4e3 100644
--- a/graph/test/javascript/expected/65-wrapper-param-reassigned.edges
+++ b/graph/test/javascript/expected/65-wrapper-param-reassigned.edges
@@ -2,51 +2,66 @@ app.js:10:23 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:10:3 FUNCTION_CALL lazyOrDefault  ->  callback_registered  app.js:10:17 <arrow>
 app.js:10:3 FUNCTION_CALL lazyOrDefault  ->  known_edge  wrap.js:17:1 lazyOrDefault
 app.js:10:3 FUNCTION_CALL lazyOrDefault(() => new A())  ->  known_edge  wrap.js:19:10 <arrow>
+app.js:10:3 FUNCTION_CALL lazyOrDefault(() => new A())  ->  multi_inferred  app.js:10:17 <arrow>
+app.js:10:3 FUNCTION_CALL lazyOrDefault(() => new A())  ->  multi_inferred  wrap.js:18:15 <arrow>
 app.js:10:3 METHOD_CALL lazyOrDefault(() => new A())().aOnly  ->  known_edge  wrap.js:2:11 aOnly
 app.js:11:3 FUNCTION_CALL lazyNullish  ->  known_edge  wrap.js:22:1 lazyNullish
 app.js:11:3 FUNCTION_CALL lazyNullish()  ->  known_edge  wrap.js:24:10 <arrow>
+app.js:11:3 FUNCTION_CALL lazyNullish()  ->  multi_inferred  wrap.js:23:10 <arrow>
 app.js:11:3 METHOD_CALL lazyNullish()().dfltOnly  ->  known_edge  wrap.js:4:14 dfltOnly
 app.js:15:15 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:15:3 FUNCTION_CALL plain  ->  callback_registered  app.js:15:9 <arrow>
 app.js:15:3 FUNCTION_CALL plain  ->  known_edge  wrap.js:27:1 plain
 app.js:15:3 FUNCTION_CALL plain(() => new A())  ->  known_edge  wrap.js:28:10 <arrow>
+app.js:15:3 FUNCTION_CALL plain(() => new A())  ->  multi_inferred  app.js:15:9 <arrow>
 app.js:15:3 METHOD_CALL plain(() => new A())().aOnly  ->  known_edge  wrap.js:2:11 aOnly
 app.js:16:15 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:16:3 FUNCTION_CALL plain  ->  callback_registered  app.js:16:9 <arrow>
 app.js:16:3 FUNCTION_CALL plain  ->  known_edge  wrap.js:27:1 plain
 app.js:16:3 FUNCTION_CALL plain(() => new A())  ->  known_edge  wrap.js:28:10 <arrow>
+app.js:16:3 FUNCTION_CALL plain(() => new A())  ->  multi_inferred  app.js:16:9 <arrow>
 app.js:16:3 METHOD_CALL plain(() => new A())().replacedOnly  ->  ambiguous_unknown  -
 app.js:17:22 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:17:3 FUNCTION_CALL otherWritten  ->  callback_registered  app.js:17:16 <arrow>
 app.js:17:3 FUNCTION_CALL otherWritten  ->  known_edge  wrap.js:31:1 otherWritten
 app.js:17:3 FUNCTION_CALL otherWritten(() => new A(), null)  ->  known_edge  wrap.js:33:10 <arrow>
+app.js:17:3 FUNCTION_CALL otherWritten(() => new A(), null)  ->  multi_inferred  app.js:17:16 <arrow>
 app.js:17:3 METHOD_CALL otherWritten(() => new A(), null)().aOnly  ->  known_edge  wrap.js:2:11 aOnly
 app.js:18:22 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:18:3 FUNCTION_CALL otherWritten  ->  callback_registered  app.js:18:16 <arrow>
 app.js:18:3 FUNCTION_CALL otherWritten  ->  known_edge  wrap.js:31:1 otherWritten
 app.js:18:3 FUNCTION_CALL otherWritten(() => new A(), null)  ->  known_edge  wrap.js:33:10 <arrow>
+app.js:18:3 FUNCTION_CALL otherWritten(() => new A(), null)  ->  multi_inferred  app.js:18:16 <arrow>
 app.js:18:3 METHOD_CALL otherWritten(() => new A(), null)().replacedOnly  ->  ambiguous_unknown  -
 app.js:4:14 FUNCTION_CALL swapped  ->  callback_registered  app.js:4:22 <arrow>
 app.js:4:14 FUNCTION_CALL swapped  ->  known_edge  wrap.js:7:1 swapped
 app.js:4:28 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:5:3 FUNCTION_CALL sw  ->  known_edge  wrap.js:9:10 <arrow>
+app.js:5:3 FUNCTION_CALL sw  ->  multi_inferred  wrap.js:8:8 <arrow>
 app.js:5:3 METHOD_CALL sw().replacedOnly  ->  known_edge  wrap.js:3:18 replacedOnly
 app.js:6:3 FUNCTION_CALL sw  ->  known_edge  wrap.js:9:10 <arrow>
+app.js:6:3 FUNCTION_CALL sw  ->  multi_inferred  wrap.js:8:8 <arrow>
 app.js:6:3 METHOD_CALL sw().aOnly  ->  ambiguous_unknown  -
 app.js:7:3 FUNCTION_CALL lazyGuard  ->  known_edge  wrap.js:12:1 lazyGuard
 app.js:7:3 FUNCTION_CALL lazyGuard(undefined)  ->  known_edge  wrap.js:14:10 <arrow>
+app.js:7:3 FUNCTION_CALL lazyGuard(undefined)  ->  multi_inferred  wrap.js:13:38 <arrow>
 app.js:7:3 METHOD_CALL lazyGuard(undefined)().replacedOnly  ->  known_edge  wrap.js:3:18 replacedOnly
 app.js:8:19 CONSTRUCTOR_CALL A  ->  implicit_constructor  -
 app.js:8:3 FUNCTION_CALL lazyGuard  ->  callback_registered  app.js:8:13 <arrow>
 app.js:8:3 FUNCTION_CALL lazyGuard  ->  known_edge  wrap.js:12:1 lazyGuard
 app.js:8:3 FUNCTION_CALL lazyGuard(() => new A())  ->  known_edge  wrap.js:14:10 <arrow>
+app.js:8:3 FUNCTION_CALL lazyGuard(() => new A())  ->  multi_inferred  app.js:8:13 <arrow>
+app.js:8:3 FUNCTION_CALL lazyGuard(() => new A())  ->  multi_inferred  wrap.js:13:38 <arrow>
 app.js:8:3 METHOD_CALL lazyGuard(() => new A())().aOnly  ->  known_edge  wrap.js:2:11 aOnly
 app.js:9:3 FUNCTION_CALL lazyOrDefault  ->  known_edge  wrap.js:17:1 lazyOrDefault
 app.js:9:3 FUNCTION_CALL lazyOrDefault()  ->  known_edge  wrap.js:19:10 <arrow>
+app.js:9:3 FUNCTION_CALL lazyOrDefault()  ->  multi_inferred  wrap.js:18:15 <arrow>
 app.js:9:3 METHOD_CALL lazyOrDefault()().dfltOnly  ->  known_edge  wrap.js:4:14 dfltOnly
 many.js:11:3 FUNCTION_CALL s21  ->  known_edge  wrap.js:9:10 <arrow>
+many.js:11:3 FUNCTION_CALL s21  ->  multi_inferred  wrap.js:8:8 <arrow>
 many.js:11:3 METHOD_CALL s21().replacedOnly  ->  known_edge  wrap.js:3:18 replacedOnly
 many.js:12:3 FUNCTION_CALL s21  ->  known_edge  wrap.js:9:10 <arrow>
+many.js:12:3 FUNCTION_CALL s21  ->  multi_inferred  wrap.js:8:8 <arrow>
 many.js:12:3 METHOD_CALL s21().aOnly  ->  ambiguous_unknown  -
 many.js:3:13 FUNCTION_CALL swapped  ->  callback_registered  many.js:3:21 <arrow>
 many.js:3:13 FUNCTION_CALL swapped  ->  known_edge  wrap.js:7:1 swapped
diff --git a/parser/src/parsers/javascript/extractors/js-module-edge-extractor.ts b/parser/src/parsers/javascript/extractors/js-module-edge-extractor.ts
index 50bd20c4..d07fcb1c 100644
--- a/parser/src/parsers/javascript/extractors/js-module-edge-extractor.ts
+++ b/parser/src/parsers/javascript/extractors/js-module-edge-extractor.ts
@@ -1214,8 +1214,20 @@ class JsModuleEdgeExtractor {
     ).resolvedModule?.resolvedFileName;
     // tsc resolves no `.vue` import itself (its extensions are fixed), so a
     // component in this program is looked up by path.
-    const resolved = resolveIn(mode) ?? (mode === ts.ModuleKind.ESNext ? resolveIn(ts.ModuleKind.CommonJS) : undefined)
+    let resolved = resolveIn(mode) ?? (mode === ts.ModuleKind.ESNext ? resolveIn(ts.ModuleKind.CommonJS) : undefined)
       ?? resolveVueSpecifier(specifier, this.options.absoluteFilePath, this.options.compilerOptions);
+    // The compiler prefers a DECLARATION to the code it describes: `require('../')` in a package
+    // whose package.json names `types: typings/index.d.ts`, or `import './lib.js'` beside a
+    // hand-written `lib.d.ts`, resolves to the .d.ts. JavaScript never loads a declaration, so
+    // the module it runs is asked for again with declarations out of sight; left alone, every
+    // value imported that way was external and each call through it untyped.
+    if (resolved !== undefined && isDeclarationPath(resolved)
+        && !resolved.includes(`${path.sep}node_modules${path.sep}`) && !resolved.includes('/node_modules/')) {
+      const runtime = resolveRuntimeFile(specifier, this.options.absoluteFilePath, this.options.compilerOptions, mode);
+      if (runtime !== undefined) {
+        resolved = runtime;
+      }
+    }
     // BOTH SIDES CANONICAL. `projectModuleHashes` is keyed by the files the analyzer
     // walked from a root it has already resolved through its symlinks; the resolver
     // answers with the real path for a package found under `node_modules` but does NOT
@@ -1280,6 +1292,36 @@ class JsModuleEdgeExtractor {
 
 // ---------------------------------------------------------------------------
 
+const DECLARATION_PATH = /\.d\.[cm]?ts$/;
+
+function isDeclarationPath(file: string): boolean {
+  return DECLARATION_PATH.test(file);
+}
+
+/**
+ * The file a JavaScript runtime would load for `specifier`: the compiler's resolution with every
+ * declaration file hidden from it, so `types`/`typings` and a `.d.ts` beside a `.js` fall through to
+ * `main`, the `exports` code conditions and the `.js` itself. `undefined` when nothing but a
+ * declaration answers (a types-only package), which leaves the first answer standing.
+ */
+function resolveRuntimeFile(
+  specifier: string,
+  fromFile: string,
+  options: ts.CompilerOptions,
+  mode: ts.ResolutionMode
+): string | undefined {
+  const host: ts.ModuleResolutionHost = {
+    ...ts.sys,
+    fileExists: (f) => !isDeclarationPath(f) && ts.sys.fileExists(f),
+  };
+  const answer = (m: ts.ResolutionMode): string | undefined => {
+    const r = ts.resolveModuleName(specifier, fromFile, { ...options, allowJs: true }, host, undefined, undefined, m)
+      .resolvedModule?.resolvedFileName;
+    return r !== undefined && !isDeclarationPath(r) ? r : undefined;
+  };
+  return answer(mode) ?? (mode === ts.ModuleKind.ESNext ? answer(ts.ModuleKind.CommonJS) : undefined);
+}
+
 /** `createRequire(import.meta.url)`, however it was imported. */
 function isCreateRequireCall(node: ts.CallExpression): boolean {
   const callee = node.expression;
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/case.json b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/case.json
new file mode 100644
index 00000000..dcb66027
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/case.json
@@ -0,0 +1,16 @@
+{"lang": "javascript", "src": "src",
+ "checks": [
+  {"why": "calling what `promisable(op3Impl, 2)` returned runs op3Impl: the test that calls the export reaches the function the module wrapped",
+   "run": ["impact", "op3Impl", "--tests"],
+   "want": ["op3.test.js"],
+   "avoid": ["tests: 0 of", "op4.test.js"]},
+  {"why": "the same through a member of a re-exporting object: lib.op4(...) runs op4Impl, and no other wrapped function",
+   "run": ["impact", "op4Impl", "--tests"],
+   "want": ["op4.test.js"],
+   "avoid": ["op3.test.js"]},
+  {"why": "the wrapper's own call of its parameter still holds every wrapped function only per site: op3's test is not a test of op5Impl",
+   "run": ["impact", "op5Impl", "--tests"],
+   "avoid": ["op3.test.js", "op4.test.js"]},
+  {"why": "CONTROL: a wrapper whose closure never calls its parameter runs nothing it was handed, so calling the labelled export does not reach secret",
+   "run": ["impact", "secret", "--tests"],
+   "avoid": ["named.test.js"]}]}
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/index.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/index.js
new file mode 100644
index 00000000..0ca257ee
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/index.js
@@ -0,0 +1,3 @@
+import op3 from './op3.js';
+import op4 from './op4.js';
+export default { op3, op4 };
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/label.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/label.js
new file mode 100644
index 00000000..f1fd17f2
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/label.js
@@ -0,0 +1,3 @@
+export default function label(fn) {
+  return function labelled() { return fn.name; };
+}
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/named.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/named.js
new file mode 100644
index 00000000..2fda0a4c
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/named.js
@@ -0,0 +1,3 @@
+import label from './label.js';
+function secret() { return 42; }
+export default label(secret);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op0.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op0.js
new file mode 100644
index 00000000..512a36e3
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op0.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op0Impl(coll, cb) { return cb(null, coll.length + 0); }
+export default promisable(op0Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op1.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op1.js
new file mode 100644
index 00000000..64b59b8b
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op1.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op1Impl(coll, cb) { return cb(null, coll.length + 1); }
+export default promisable(op1Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op10.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op10.js
new file mode 100644
index 00000000..942919bf
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op10.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op10Impl(coll, cb) { return cb(null, coll.length + 10); }
+export default promisable(op10Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op11.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op11.js
new file mode 100644
index 00000000..fd06b995
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op11.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op11Impl(coll, cb) { return cb(null, coll.length + 11); }
+export default promisable(op11Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op12.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op12.js
new file mode 100644
index 00000000..0e1cc8ec
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op12.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op12Impl(coll, cb) { return cb(null, coll.length + 12); }
+export default promisable(op12Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op13.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op13.js
new file mode 100644
index 00000000..7333efb6
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op13.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op13Impl(coll, cb) { return cb(null, coll.length + 13); }
+export default promisable(op13Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op14.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op14.js
new file mode 100644
index 00000000..2151714c
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op14.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op14Impl(coll, cb) { return cb(null, coll.length + 14); }
+export default promisable(op14Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op15.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op15.js
new file mode 100644
index 00000000..39b600b4
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op15.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op15Impl(coll, cb) { return cb(null, coll.length + 15); }
+export default promisable(op15Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op16.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op16.js
new file mode 100644
index 00000000..4b219615
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op16.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op16Impl(coll, cb) { return cb(null, coll.length + 16); }
+export default promisable(op16Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op17.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op17.js
new file mode 100644
index 00000000..3f40d043
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op17.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op17Impl(coll, cb) { return cb(null, coll.length + 17); }
+export default promisable(op17Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op18.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op18.js
new file mode 100644
index 00000000..2844d30b
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op18.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op18Impl(coll, cb) { return cb(null, coll.length + 18); }
+export default promisable(op18Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op19.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op19.js
new file mode 100644
index 00000000..5ae0a6cb
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op19.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op19Impl(coll, cb) { return cb(null, coll.length + 19); }
+export default promisable(op19Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op2.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op2.js
new file mode 100644
index 00000000..6332264f
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op2.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op2Impl(coll, cb) { return cb(null, coll.length + 2); }
+export default promisable(op2Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op20.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op20.js
new file mode 100644
index 00000000..f69644bc
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op20.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op20Impl(coll, cb) { return cb(null, coll.length + 20); }
+export default promisable(op20Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op21.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op21.js
new file mode 100644
index 00000000..bfed47cf
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op21.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op21Impl(coll, cb) { return cb(null, coll.length + 21); }
+export default promisable(op21Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op22.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op22.js
new file mode 100644
index 00000000..b7b24386
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op22.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op22Impl(coll, cb) { return cb(null, coll.length + 22); }
+export default promisable(op22Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op23.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op23.js
new file mode 100644
index 00000000..bf228d69
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op23.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op23Impl(coll, cb) { return cb(null, coll.length + 23); }
+export default promisable(op23Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op3.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op3.js
new file mode 100644
index 00000000..19c2ac86
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op3.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op3Impl(coll, cb) { return cb(null, coll.length + 3); }
+export default promisable(op3Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op4.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op4.js
new file mode 100644
index 00000000..f38f30c4
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op4.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op4Impl(coll, cb) { return cb(null, coll.length + 4); }
+export default promisable(op4Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op5.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op5.js
new file mode 100644
index 00000000..1898ad42
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op5.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op5Impl(coll, cb) { return cb(null, coll.length + 5); }
+export default promisable(op5Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op6.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op6.js
new file mode 100644
index 00000000..820234a4
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op6.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op6Impl(coll, cb) { return cb(null, coll.length + 6); }
+export default promisable(op6Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op7.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op7.js
new file mode 100644
index 00000000..53e4e1a6
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op7.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op7Impl(coll, cb) { return cb(null, coll.length + 7); }
+export default promisable(op7Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op8.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op8.js
new file mode 100644
index 00000000..873712ec
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op8.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op8Impl(coll, cb) { return cb(null, coll.length + 8); }
+export default promisable(op8Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op9.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op9.js
new file mode 100644
index 00000000..f7dfa907
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/op9.js
@@ -0,0 +1,3 @@
+import promisable from './promisable.js';
+function op9Impl(coll, cb) { return cb(null, coll.length + 9); }
+export default promisable(op9Impl, 2);
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/promisable.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/promisable.js
new file mode 100644
index 00000000..85733214
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/lib/promisable.js
@@ -0,0 +1,12 @@
+export default function promisable(fn, arity) {
+  function run(...args) {
+    if (typeof args[arity - 1] === 'function') {
+      return fn.apply(this, args);
+    }
+    return new Promise((resolve) => {
+      args[arity - 1] = (err, value) => resolve(value);
+      fn.apply(this, args);
+    });
+  }
+  return run;
+}
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/package.json b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/package.json
new file mode 100644
index 00000000..5a4a9bf6
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/package.json
@@ -0,0 +1 @@
+{"name": "wrapkit", "type": "module"}
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/named.test.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/named.test.js
new file mode 100644
index 00000000..82c77371
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/named.test.js
@@ -0,0 +1,2 @@
+import named from '../lib/named.js';
+it('named', () => { named(); });
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op3.test.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op3.test.js
new file mode 100644
index 00000000..9ef95bfc
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op3.test.js
@@ -0,0 +1,2 @@
+import op3 from '../lib/op3.js';
+it('op3', (done) => { op3([1], done); });
diff --git a/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op4.test.js b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op4.test.js
new file mode 100644
index 00000000..c82a1032
--- /dev/null
+++ b/tests/cases/javascript/call-through-a-wrapper-runs-its-argument/src/test/op4.test.js
@@ -0,0 +1,2 @@
+import lib from '../lib/index.js';
+it('op4', (done) => { lib.op4([1, 2], done); });
diff --git a/tests/cases/javascript/declaration-beside-the-code/case.json b/tests/cases/javascript/declaration-beside-the-code/case.json
new file mode 100644
index 00000000..2257c3b4
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/case.json
@@ -0,0 +1,62 @@
+{
+ "lang": "javascript",
+ "src": "src",
+ "checks": [
+  {
+   "why": "require('../') in a package whose package.json names a hand-written declaration (types / an exports types condition) loads index.js at runtime: the test that calls the class it exports reaches the method",
+   "run": [
+    "impact",
+    "Reader.skipBlank",
+    "--tests"
+   ],
+   "want": [
+    "reader.test.js",
+    "tests: 1 of"
+   ],
+   "avoid": [
+    "tests: 0 of"
+   ]
+  },
+  {
+   "why": "require('../lib/format.js') beside a format.d.ts loads the .js: the test's call is an exact edge, not a name match",
+   "run": [
+    "path",
+    "src/test/format.test.js",
+    "wrap"
+   ],
+   "want": [
+    "known_edge"
+   ],
+   "avoid": [
+    "receiver not typed",
+    "callee is"
+   ]
+  },
+  {
+   "why": "path from the test file is an exact chain through the runtime module, not an unknown receiver",
+   "run": [
+    "path",
+    "src/test/reader.test.js",
+    "Reader.readAll"
+   ],
+   "want": [
+    "known_edge"
+   ],
+   "avoid": [
+    "receiver not typed"
+   ]
+  },
+  {
+   "why": "CONTROL: a module that exists only as a declaration has no code to run; a call through it stays unresolved and is never linked to a same-named project method",
+   "run": [
+    "path",
+    "src/test/shape.test.js",
+    "Square.area"
+   ],
+   "expect_error": true,
+   "avoid": [
+    "known_edge"
+   ]
+  }
+ ]
+}
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/index.js b/tests/cases/javascript/declaration-beside-the-code/src/index.js
new file mode 100644
index 00000000..5343d15f
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/index.js
@@ -0,0 +1,3 @@
+const { Reader } = require('./lib/reader.js');
+exports.Reader = Reader;
+exports.reader = new Reader();
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/lib/format.d.ts b/tests/cases/javascript/declaration-beside-the-code/src/lib/format.d.ts
new file mode 100644
index 00000000..a3746a06
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/lib/format.d.ts
@@ -0,0 +1 @@
+export function wrap(text: string): string;
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/lib/format.js b/tests/cases/javascript/declaration-beside-the-code/src/lib/format.js
new file mode 100644
index 00000000..c2f69520
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/lib/format.js
@@ -0,0 +1,2 @@
+function wrap(text) { return `[${text}]`; }
+module.exports = { wrap };
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/lib/geometry.js b/tests/cases/javascript/declaration-beside-the-code/src/lib/geometry.js
new file mode 100644
index 00000000..a7895a60
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/lib/geometry.js
@@ -0,0 +1,2 @@
+class Square { area() { return 4; } }
+module.exports = { Square };
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/lib/reader.js b/tests/cases/javascript/declaration-beside-the-code/src/lib/reader.js
new file mode 100644
index 00000000..e4e12860
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/lib/reader.js
@@ -0,0 +1,5 @@
+class Reader {
+  readAll(argv) { return this.skipBlank(argv); }
+  skipBlank(argv) { return argv.length; }
+}
+exports.Reader = Reader;
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/lib/shape.d.ts b/tests/cases/javascript/declaration-beside-the-code/src/lib/shape.d.ts
new file mode 100644
index 00000000..68e7e66a
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/lib/shape.d.ts
@@ -0,0 +1 @@
+export interface Shape { area(): number; }
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/package.json b/tests/cases/javascript/declaration-beside-the-code/src/package.json
new file mode 100644
index 00000000..572becf2
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/package.json
@@ -0,0 +1,2 @@
+{"name": "readkit", "main": "./index.js", "types": "./typings/index.d.ts",
+ "exports": {".": {"require": {"types": "./typings/index.d.ts", "default": "./index.js"}, "default": "./index.js"}}}
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/test/format.test.js b/tests/cases/javascript/declaration-beside-the-code/src/test/format.test.js
new file mode 100644
index 00000000..29eecc05
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/test/format.test.js
@@ -0,0 +1,2 @@
+const { wrap } = require('../lib/format.js');
+test('wrap', () => { expect(wrap('a')).toBe('[a]'); });
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/test/reader.test.js b/tests/cases/javascript/declaration-beside-the-code/src/test/reader.test.js
new file mode 100644
index 00000000..d204209c
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/test/reader.test.js
@@ -0,0 +1,5 @@
+const kit = require('../');
+test('readAll', () => {
+  const reader = new kit.Reader();
+  expect(() => reader.readAll(['x'])).not.toThrow();
+});
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/test/shape.test.js b/tests/cases/javascript/declaration-beside-the-code/src/test/shape.test.js
new file mode 100644
index 00000000..77f0280a
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/test/shape.test.js
@@ -0,0 +1,2 @@
+const shape = require('../lib/shape');
+test('shape', () => { expect(shape.area()).toBe(1); });
diff --git a/tests/cases/javascript/declaration-beside-the-code/src/typings/index.d.ts b/tests/cases/javascript/declaration-beside-the-code/src/typings/index.d.ts
new file mode 100644
index 00000000..b647e452
--- /dev/null
+++ b/tests/cases/javascript/declaration-beside-the-code/src/typings/index.d.ts
@@ -0,0 +1,2 @@
+export class Reader { readAll(argv: string[]): number; }
+export const reader: Reader;
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/case.json b/tests/cases/javascript/tests-do-not-make-the-api-hot/case.json
new file mode 100644
index 00000000..cd47315d
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/case.json
@@ -0,0 +1,55 @@
+{
+ "lang": "javascript",
+ "src": "src",
+ "checks": [
+  {
+   "why": "a constructor the tests call 24 times is not a generic utility: the program's own `new Codec(name, {decode})` reaches the parameter, so `codec.decode()` in the loader calls the stored callback and the loader's test reaches it",
+   "run": [
+    "impact",
+    "decode_alpha",
+    "--tests"
+   ],
+   "want": [
+    "load",
+    "load.test.js"
+   ],
+   "avoid": [
+    "tests: 0 of"
+   ]
+  },
+  {
+   "why": "a test's argument does not flow into the program's parameter: the loader's call is one of the three library callbacks and the fallback, never a test's own decoder",
+   "run": [
+    "impact",
+    "customDecode3"
+   ],
+   "avoid": [
+    "load   "
+   ]
+  },
+  {
+   "why": "CONTROL: a utility the PROGRAM calls from 23 places stays capped: what it is handed is not followed, so the callback is not a callee of each",
+   "run": [
+    "impact",
+    "onItem"
+   ],
+   "avoid": [
+    "each   "
+   ]
+  },
+  {
+   "why": "a test still hands the program what it calls back: a plugin passed from a test to core.extend is called with the class, so the method it adds is what the test's `core().shout()` calls (what flowed before keeps flowing)",
+   "run": [
+    "path",
+    "src/test/plugin.test.js",
+    "shout"
+   ],
+   "want": [
+    "known_edge"
+   ],
+   "avoid": [
+    "receiver not typed"
+   ]
+  }
+ ]
+}
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codec.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codec.js
new file mode 100644
index 00000000..cbf366d7
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codec.js
@@ -0,0 +1,7 @@
+'use strict';
+function Codec(name, options) {
+  options = options || {};
+  this.name = name;
+  this.decode = options['decode'] || function () { return true; };
+}
+module.exports = Codec;
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/alpha.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/alpha.js
new file mode 100644
index 00000000..a5864f2e
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/alpha.js
@@ -0,0 +1,4 @@
+'use strict';
+var Codec = require('../codec');
+function decode_alpha(data) { return data === 'alpha'; }
+module.exports = new Codec('codec:alpha', { decode: decode_alpha });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/beta.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/beta.js
new file mode 100644
index 00000000..8b97967e
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/beta.js
@@ -0,0 +1,4 @@
+'use strict';
+var Codec = require('../codec');
+function decode_beta(data) { return data === 'beta'; }
+module.exports = new Codec('codec:beta', { decode: decode_beta });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/gamma.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/gamma.js
new file mode 100644
index 00000000..e1d9291d
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/codecs/gamma.js
@@ -0,0 +1,4 @@
+'use strict';
+var Codec = require('../codec');
+function decode_gamma(data) { return data === 'gamma'; }
+module.exports = new Codec('codec:gamma', { decode: decode_gamma });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/core.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/core.js
new file mode 100644
index 00000000..8424af35
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/core.js
@@ -0,0 +1,5 @@
+'use strict';
+class Core {}
+function core() { return new Core(); }
+core.extend = (plugin) => { plugin(Core); return core; };
+module.exports = core;
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/each.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/each.js
new file mode 100644
index 00000000..94936ac2
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/each.js
@@ -0,0 +1,3 @@
+'use strict';
+function each(list, fn) { for (var i = 0; i < list.length; i++) fn(list[i]); }
+module.exports = each;
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/loader.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/loader.js
new file mode 100644
index 00000000..2086d532
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/loader.js
@@ -0,0 +1,10 @@
+'use strict';
+var codecs = [require('./codecs/alpha'), require('./codecs/beta'), require('./codecs/gamma')];
+function load(x) {
+  for (var i = 0; i < codecs.length; i++) {
+    var codec = codecs[i];
+    if (codec.decode(x)) return codec.name;
+  }
+  return null;
+}
+module.exports = { load, Codec: require('./codec') };
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/plugins/shout.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/plugins/shout.js
new file mode 100644
index 00000000..21df4a2e
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/plugins/shout.js
@@ -0,0 +1,4 @@
+'use strict';
+module.exports = (C) => {
+  C.prototype.shout = function shout() { return 'HEY'; };
+};
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/walk.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/walk.js
new file mode 100644
index 00000000..bee2917a
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/lib/walk.js
@@ -0,0 +1,29 @@
+'use strict';
+var each = require('./each');
+function onItem(x) { return x; }
+function walk(list) {
+  each(list, function step0(x) { return x + 0; });
+  each(list, function step1(x) { return x + 1; });
+  each(list, function step2(x) { return x + 2; });
+  each(list, function step3(x) { return x + 3; });
+  each(list, function step4(x) { return x + 4; });
+  each(list, function step5(x) { return x + 5; });
+  each(list, function step6(x) { return x + 6; });
+  each(list, function step7(x) { return x + 7; });
+  each(list, function step8(x) { return x + 8; });
+  each(list, function step9(x) { return x + 9; });
+  each(list, function step10(x) { return x + 10; });
+  each(list, function step11(x) { return x + 11; });
+  each(list, function step12(x) { return x + 12; });
+  each(list, function step13(x) { return x + 13; });
+  each(list, function step14(x) { return x + 14; });
+  each(list, function step15(x) { return x + 15; });
+  each(list, function step16(x) { return x + 16; });
+  each(list, function step17(x) { return x + 17; });
+  each(list, function step18(x) { return x + 18; });
+  each(list, function step19(x) { return x + 19; });
+  each(list, function step20(x) { return x + 20; });
+  each(list, function step21(x) { return x + 21; });
+  each(list, onItem);
+}
+module.exports = { walk, onItem };
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/package.json b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/package.json
new file mode 100644
index 00000000..8b109c46
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/package.json
@@ -0,0 +1 @@
+{"name": "codeckit"}
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/custom.test.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/custom.test.js
new file mode 100644
index 00000000..d64224b8
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/custom.test.js
@@ -0,0 +1,25 @@
+const { Codec } = require('../lib/loader');
+test('custom 0', () => { const t = new Codec('!c0', { decode: function customDecode0(d) { return d === 0; } }); expect(t.decode(0)).toBe(true); });
+test('custom 1', () => { const t = new Codec('!c1', { decode: function customDecode1(d) { return d === 1; } }); expect(t.decode(1)).toBe(true); });
+test('custom 2', () => { const t = new Codec('!c2', { decode: function customDecode2(d) { return d === 2; } }); expect(t.decode(2)).toBe(true); });
+test('custom 3', () => { const t = new Codec('!c3', { decode: function customDecode3(d) { return d === 3; } }); expect(t.decode(3)).toBe(true); });
+test('custom 4', () => { const t = new Codec('!c4', { decode: function customDecode4(d) { return d === 4; } }); expect(t.decode(4)).toBe(true); });
+test('custom 5', () => { const t = new Codec('!c5', { decode: function customDecode5(d) { return d === 5; } }); expect(t.decode(5)).toBe(true); });
+test('custom 6', () => { const t = new Codec('!c6', { decode: function customDecode6(d) { return d === 6; } }); expect(t.decode(6)).toBe(true); });
+test('custom 7', () => { const t = new Codec('!c7', { decode: function customDecode7(d) { return d === 7; } }); expect(t.decode(7)).toBe(true); });
+test('custom 8', () => { const t = new Codec('!c8', { decode: function customDecode8(d) { return d === 8; } }); expect(t.decode(8)).toBe(true); });
+test('custom 9', () => { const t = new Codec('!c9', { decode: function customDecode9(d) { return d === 9; } }); expect(t.decode(9)).toBe(true); });
+test('custom 10', () => { const t = new Codec('!c10', { decode: function customDecode10(d) { return d === 10; } }); expect(t.decode(10)).toBe(true); });
+test('custom 11', () => { const t = new Codec('!c11', { decode: function customDecode11(d) { return d === 11; } }); expect(t.decode(11)).toBe(true); });
+test('custom 12', () => { const t = new Codec('!c12', { decode: function customDecode12(d) { return d === 12; } }); expect(t.decode(12)).toBe(true); });
+test('custom 13', () => { const t = new Codec('!c13', { decode: function customDecode13(d) { return d === 13; } }); expect(t.decode(13)).toBe(true); });
+test('custom 14', () => { const t = new Codec('!c14', { decode: function customDecode14(d) { return d === 14; } }); expect(t.decode(14)).toBe(true); });
+test('custom 15', () => { const t = new Codec('!c15', { decode: function customDecode15(d) { return d === 15; } }); expect(t.decode(15)).toBe(true); });
+test('custom 16', () => { const t = new Codec('!c16', { decode: function customDecode16(d) { return d === 16; } }); expect(t.decode(16)).toBe(true); });
+test('custom 17', () => { const t = new Codec('!c17', { decode: function customDecode17(d) { return d === 17; } }); expect(t.decode(17)).toBe(true); });
+test('custom 18', () => { const t = new Codec('!c18', { decode: function customDecode18(d) { return d === 18; } }); expect(t.decode(18)).toBe(true); });
+test('custom 19', () => { const t = new Codec('!c19', { decode: function customDecode19(d) { return d === 19; } }); expect(t.decode(19)).toBe(true); });
+test('custom 20', () => { const t = new Codec('!c20', { decode: function customDecode20(d) { return d === 20; } }); expect(t.decode(20)).toBe(true); });
+test('custom 21', () => { const t = new Codec('!c21', { decode: function customDecode21(d) { return d === 21; } }); expect(t.decode(21)).toBe(true); });
+test('custom 22', () => { const t = new Codec('!c22', { decode: function customDecode22(d) { return d === 22; } }); expect(t.decode(22)).toBe(true); });
+test('custom 23', () => { const t = new Codec('!c23', { decode: function customDecode23(d) { return d === 23; } }); expect(t.decode(23)).toBe(true); });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/load.test.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/load.test.js
new file mode 100644
index 00000000..9cffc0a6
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/load.test.js
@@ -0,0 +1,2 @@
+const { load } = require('../lib/loader');
+test('alpha', () => { expect(load('alpha')).toBe('codec:alpha'); });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/plugin.test.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/plugin.test.js
new file mode 100644
index 00000000..f4478092
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/plugin.test.js
@@ -0,0 +1,4 @@
+const core = require('../lib/core');
+const shoutPlugin = require('../lib/plugins/shout');
+core.extend(shoutPlugin);
+test('shout', () => { expect(core().shout()).toBe('HEY'); });
diff --git a/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/walk.test.js b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/walk.test.js
new file mode 100644
index 00000000..4234f11f
--- /dev/null
+++ b/tests/cases/javascript/tests-do-not-make-the-api-hot/src/test/walk.test.js
@@ -0,0 +1,2 @@
+const { walk } = require('../lib/walk');
+test('walk', () => { walk([1]); });