package linthost

import "testing"

// TestCommandFormatPreservesCommentsInReflow guards against print-width
// silently deleting comments when it reflows a list. When these list targets
// carry a gap comment the rule abstains, leaving the authored source, including
// the comment, byte-identical. A comment-free twin requires reflow with its
// argument values and call binding preserved. Each commented source below
// carries a comment in a different position; the first three are flat lines that
// overflow printWidth 60, and the last two are already-broken lists.
//
//  1. Seed five sources, each carrying a comment inside a list, and one
//     comment-free copy of the first call.
//  2. Run `ttsc format` with printWidth 60 on each.
//  3. Require the five commented files byte-identical, so no comment is deleted
//     or moved, and the comment-free call reflowed.
//
// @evidence contracts/testing.md#behavioral-verification Six subcases run the in-process `format` command at printWidth 60: five on lists carrying comments (inline block comment in call arguments, block comment in an array, trailing block comment in an object, trailing line comment on an array element, trailing block comment on a single-property object) requiring each byte-identical so no comment is deleted or moved, and one comment-free twin of the first call that must reflow.
// @evidence contracts/testing.md#independent-expectations Five complete authored literals independently require comment and surrounding source preservation; the twin's independent complete literal requires one-argument-per-line reflow with the same binding, callee and argument values. Nothing is derived from formatter output or an independent Prettier invocation.
// @evidence contracts/testing.md#distinguishing-cases Each subcase varies the comment position and comment kind in a different list shape; three overflow flat lines that would otherwise be reflowed. The comment cases are fixed points, so only preservation, not a comment-aware reflow, is asserted; the comment-free twin shows the call otherwise reflows.
// @evidence contracts/testing.md#execution-ownership In-process Go unit: five preservation subcases call run with format through assertFormatUnchangedWithFormat and the positive twin through assertFormatResultWithFormat, each on a temp-dir project; no child process, built binary or installed consumer.
func TestCommandFormatPreservesCommentsInReflow(t *testing.T) {
  pw := map[string]any{"printWidth": 60}
  t.Run("call_arg_inline_block_comment", func(t *testing.T) {
    assertFormatUnchangedWithFormat(t, `const a = veryLongFunctionCallNameHere(firstArgumentValue, /* inline */ secondArgumentValueLong);
`, pw)
  })
  // The comment-free twin of the first source: the same call is reflowed, so
  // the abstentions around it come from the comment and not from the shape.
  t.Run("same_call_without_comment_reflows", func(t *testing.T) {
    assertFormatResultWithFormat(t, `const a = veryLongFunctionCallNameHere(firstArgumentValue, secondArgumentValueLong);
`, `const a = veryLongFunctionCallNameHere(
  firstArgumentValue,
  secondArgumentValueLong,
);
`, pw)
  })
  t.Run("array_inline_block_comment", func(t *testing.T) {
    assertFormatUnchangedWithFormat(t, `const b = [firstElementValueHere, /* mid */ secondElementValueHereToo, thirdEl];
`, pw)
  })
  t.Run("object_trailing_block_comment", func(t *testing.T) {
    assertFormatUnchangedWithFormat(t, `const c = { preserveSymlinks: false /* trailing */, otherOptionValueHereToBreak: true };
`, pw)
  })
  // a line comment trailing an array element (the vscode korean.ts shape):
  // the element list already spans lines because the comment forces it, so
  // reflow must not drop the `// ...`.
  t.Run("array_element_trailing_line_comment", func(t *testing.T) {
    assertFormatUnchangedWithFormat(t, `const arr = [
  firstElementValueHere, // trailing one
  secondElementValueHere,
  thirdElementValueHere,
];
`, pw)
  })
  // a single-property object whose value carries a trailing block comment and
  // overflows: reflow must keep the comment.
  t.Run("object_single_prop_trailing_comment", func(t *testing.T) {
    assertFormatUnchangedWithFormat(t, `const d = {
  preserveSymlinksForThisLongOptionName: false /* copying to another device */,
};
`, pw)
  })
}