module

import all Lean.Meta.Hint
meta import Lean.Meta.Hint

/-! # Word-level diffs in hint suggestions

Word-level diffs in hint suggestions require careful display of whitespace, since it is frequently
impossible to both accurately render both deleted and inserted whitespace while also displaying a
snippet that recognizably maps to what will be inserted. These tests exercise the behavior of the
word-level diff generator to ensure that it is reasonable.
-/

open Lean Meta Hint

/-! ## Test Word Diff Behavior -/

/-- info: "one two ̲t̲h̲r̲e̲e̲" -/
#guard_msgs in
#eval readableDiff.wordDiff "one two" "one two three" |> mkDiffString

/-- info: "o̵n̵e̵a̲ two ̲t̲h̲r̲e̲e̲" -/
#guard_msgs in
#eval readableDiff.wordDiff "one\ntwo" "a two three" |> mkDiffString

/-- info: "o̵n̵e̵a̲ ̵\n̲two ̲t̲h̲r̲e̲e̲" -/
#guard_msgs in
#eval readableDiff.wordDiff "one two" "a\ntwo three" |> mkDiffString

/-- info: "one two" -/
#guard_msgs in
#eval readableDiff.wordDiff "one\ntwo" "one two" |> mkDiffString

/-- info: "one t̵w̵o̵ ̵three" -/
#guard_msgs in
#eval readableDiff.wordDiff "one two three" "one three" |> mkDiffString

/-- info: "a  ̵b" -/
#guard_msgs in
#eval readableDiff.wordDiff "a  b" "a b" |> mkDiffString

/-- info: "a ̵b̵" -/
#guard_msgs in
#eval readableDiff.wordDiff "a b" "a" |> mkDiffString

/-- info: "a̵b c" -/
#guard_msgs in
#eval readableDiff.wordDiff "a\nb c" "b c" |> mkDiffString

/--
info: "a l̵o̵n̵g̵e̵r̵l̲o̲n̲g̲\tstring w̵i̵t̵h̵ ̵ ̵ ̵w̵h̵i̵t̵e̵s̵p̵a̵c̵e̵in strange ̵\n̲\n̲p̵l̵a̵c̵e̵s̵\n̵a̵n̵d̵ ̵u̵n̵u̵s̵u̵a̵l̵spaces"
-/
#guard_msgs in
#eval readableDiff.wordDiff
  "a longer\nstring with   whitespace\n  in strange\nplaces and\n\nunusual\tspaces"
  "a long\tstring in strange\n\nspaces"
  |> mkDiffString

/--
info: def f (̵x̵ ̵:̵ ̵N̵a̵t̵)̵x̲ := x + 1
#check let c̵x̲ := 3̵1̵5̲ in
    f c̵x̲
-/
#guard_msgs in
#eval IO.println <| readableDiff.wordDiff
  "def f (x : Nat) := x + 1\n#check let c := 31 in\n  f c"
  "def f x := x + 1\n#check let x := 5 in\n    f x"
  |> mkDiffString

/-! ## Test Word Granularity Selection -/

/-- info: "simp [mergeTR.go, m̵e̵r̵g̵e̵,̵ ̵reverseAux_eq]" -/
#guard_msgs in
#eval readableDiff
  "simp [mergeTR.go, merge, reverseAux_eq]" "simp [mergeTR.go, reverseAux_eq]" |> mkDiffString

/--
info: "r̵w̵s̲i̲m̲p̲ only [̵m̵e̵r̵g̵e̵T̵R̵.̵g̵o̵]̵[̲m̲e̲r̲g̲e̲T̲R̲.̲g̲o̲,̲ ̲m̲e̲r̲g̲e̲,̲ ̲r̲e̲v̲e̲r̲s̲e̲A̲u̲x̲_̲e̲q̲]̲"
-/
#guard_msgs in
#eval readableDiff
  "rw only [mergeTR.go]"
  "simp only [mergeTR.go, merge, reverseAux_eq]" |> mkDiffString

/-! ## Test Whitespace-Diff Handling -/

/-- info: "  ̵rw  ̵ ̵ ̵only [h]" -/
#guard_msgs in
#eval readableDiff.wordDiff "  rw    only [h]" " rw only [h]" |> mkDiffString

/-- info: " ̲ ̲w1   w2 ̵ ̵ ̵\t̲w3 ̲ ̲ ̲ ̲ ̲ ̲ ̲w̲4̲" -/
#guard_msgs in
#eval readableDiff.wordDiff "w1\nw2   w3" "  w1   w2\tw3       w4" |> mkDiffString

/-- info: " ̵ ̵x    ̲ ̲ ̲ ̲ ̲y̵ ̵ ̵ ̵z ̵" -/
#guard_msgs in
#eval readableDiff.wordDiff "  x   y   z " "x        z" |> mkDiffString