{
  // A string longer than the limit renders as an excerpt of that length, and
  // then its actual length.
  "/options": { maxStringLength: 5 },

  "past the limit": "abcdefgh",

  "at the limit": "abcde",

  "in an object": { s: "abcdefgh" },

  "in an array": ["abcdefgh"],

  "class instance's `toString()` form": new (class Foo {
    toString() {
      return "abcdefgh";
    }
  })(),

  // A multi-line string cut by the limit renders the cut line's excerpt with
  // a ` +` of its own, and then the length.
  "cut inside the second line": "abc\ndef",

  // An excerpt never ends in half of a surrogate pair: a pair the limit
  // would split is dropped, and one the limit ends after is kept.
  "surrogate pair split by the limit": "abcd\u{1F600}x",

  "surrogate pair ending at the limit": "abc\u{1F600}xy",
}

--

past the limit:
"abcde"+...length:8
"abcde" +
  ... length: 8
{
  "/partialString": {
    length: 8,
    excerpt: "abcde"
  }
}

at the limit:
"abcde"
"abcde"
"abcde"

in an object:
{s:"abcde"+...length:8}
{
  s: "abcde" +
    ... length: 8
}
{
  s: {
    "/partialString": {
      length: 8,
      excerpt: "abcde"
    }
  }
}

in an array:
["abcde"+...length:8]
[
  "abcde" +
    ... length: 8
]
[
  {
    "/partialString": {
      length: 8,
      excerpt: "abcde"
    }
  }
]

class instance's `toString()` form:
/Foo("abcde"+...length:8)
/Foo("abcde" +
  ... length: 8)
{
  "/Foo": {
    "/partialString": {
      length: 8,
      excerpt: "abcde"
    }
  }
}

cut inside the second line:
"abc\nd"+...length:7
"abc\n" +
  "d" +
  ... length: 7
{
  "/partialString": {
    length: 7,
    excerpt: "abc\n" +
      "d"
  }
}

surrogate pair split by the limit:
"abcd"+...length:7
"abcd" +
  ... length: 7
{
  "/partialString": {
    length: 7,
    excerpt: "abcd"
  }
}

surrogate pair ending at the limit:
"abc😀"+...length:7
"abc😀" +
  ... length: 7
{
  "/partialString": {
    length: 7,
    excerpt: "abc😀"
  }
}