message: chore(compiler-sfc): replace `substr` with `slice`
diff: @@ -38,7 +38,7 @@ function transform(
  }
  const imageCandidates: ImageCandidate[] = value
  - .substr(1, value.length - 2)
  + .slice(1, -1)
  .split(',')
  .map(s => {
  // The attribute value arrives here with all whitespace, except
  