javascript: a function assigned to exports.x, obj.x or an object-literal key is named for the property

[swapnilpaliwal-sd]

Symptom

In JavaScript, a function assigned to exports.x, module.exports.x or obj.x, or used as an object-literal key's value ({ all: page => … }), was indexed as <function-expression> / <arrow>. The call edges to it resolved, but impact getUser answered type getUser (not declared here) and impact Articles.all answered nothing named. Only a file:line target reached the declaration.

Fix

The index's naming pass already names const x = function … after its variable. It now also names a function expression that is:

• the right side of recv.key = …, with a non-computed property target: the name is key, and the owner is recv as written (Foo.prototype → Foo); there is no owner for exports, module.exports or this;
• the value of a non-computed key in an object literal: the name is the key, and the owner is the variable the literal initialises, or the key chain of the enclosing literal.

A named function expression keeps its own name, since only placeholders are renamed, and an arrow passed as an argument stays anonymous.

Tests

• New case tests/cases/javascript/member-assigned-function-names: 7/7 checks pass. Without the fix 5 of them fail, while the 2 CONTROL checks (a named function expression keeps its name; an argument arrow stays <arrow>; method shorthand is unchanged) pass either way.
• python3 tests/run.py: 251 of 253 checks pass; the 2 PENDING are tracked by engine: a function placed in an array or table and invoked by iteration has no caller, so everything downstream of it loses its callers too #967.
• python3 tests/fastpath.py: 4 of 4 shapes pass.

Measurements

	call_edges	symbols	placeholder symbols	owned symbols	index time
fixture before → after	16 → 16	16 → 16	9 → 3	0 → 3	2s → 2s
a real React/Redux app before → after	432 → 432	337 → 323	159 → 80	36 → 62	147s → 143s

On the real app, all 79 changed lines are renames, e.g. <arrow> → Articles.all, Auth.login, requests.get, and onLoad in a mapDispatchToProps literal. The 14 fewer symbols are this.x = ev => … field rows at the same line, now folded into the function they hold, the same way a const x = function variable row already is.

The same shape in TypeScript is #1585.