package linthost

import "testing"

// TestFixNoVarReplacesForInHeaderBinding verifies no-var rewrites a safe
// `for (var key in …)` header to `let`.
//
// This module fixture has no initializer or header self-reference, and its
// only key read is directly inside the body. No closure, direct eval or
// post-loop read observes the binding, so fresh `let` bindings preserve
// the body's key sequence and the rewrite must fire (issue #409).
//
//  1. Parse a `for...in` statement declaring `var key` and reading it in the
//     body.
//  2. Apply the no-var finding's text edit through the disk-backed fixer.
//  3. Assert only the `var` keyword changed to `let`.
//
// An explicit module owns the binding; var does not create a global-object property.
//
// @evidence contracts/testing.md#behavioral-verification no-var fixes the plain key binding of a for-in header.
// @evidence contracts/testing.md#independent-expectations The literal for-let result preserves the enumerated object and key use, requiring only a keyword edit.
// @evidence contracts/testing.md#distinguishing-cases The header has no initializer, self-reference or closure capture; Annex-B initializer and self-reference variants remain no-fix elsewhere.
// @evidence contracts/testing.md#execution-ownership TestFixNoVarReplacesForInHeaderBinding owns this for-in fixture through assertFixSnapshot/no-var.
func TestFixNoVarReplacesForInHeaderBinding(t *testing.T) {
  assertFixSnapshot(
    t,
    "no-var",
    "for (var key in { a: 1 }) {\n  JSON.stringify(key);\n}\nexport {};\n",
    "for (let key in { a: 1 }) {\n  JSON.stringify(key);\n}\nexport {};\n",
  )
}