Description

Fixes #6195

Problem

_.invert and _.invertBy silently drop keys when the inverted value is __proto__:

_.invert({ userId: "alice", role: "__proto__", team: "eng" })
// Actual:   { alice: "userId", eng: "team" }
// Expected: { alice: "userId", __proto__: "role", eng: "team" }

The root cause is result[value] = key — when value is "__proto__", this triggers the __proto__ accessor on Object.prototype, setting the prototype instead of a data property.

Fix

Changed both invert and invertBy to use baseAssignValue instead of direct property assignment. baseAssignValue already has correct __proto__ handling via Object.defineProperty, consistent with the rest of lodash (e.g., mapKeys, merge, assign).

• invert: result[value] = key → baseAssignValue(result, value, key)
• invertBy: result[value] = [key] → baseAssignValue(result, value, [key])

The hasOwnProperty.call(result, value) check in invertBy already works correctly for __proto__ (it checks own properties), so only the else branch needed changing.

Verification

_.invert({ userId: "alice", role: "__proto__", team: "eng" })
// => { alice: "userId", __proto__: "role", eng: "team" } ✅

_.invertBy({ a: "x", b: "__proto__", c: "x" })
// => { x: ["a", "c"], __proto__: ["b"] } ✅