Lack of specificity in highlighting when doing complex zooming

[filipsch]

For complex zooming in, the highlighting is not specific enough.

Reproducible example (in words)

Take the following exercise:

# solution
j <- 0
for (i in 1:4) {
  if (i %% 2 == 0) {
    j <- j + 1
  }
}

# sct
ex() %>%
  check_for() %>%
  check_body() %>%
  check_if_else() %>%
  check_if() %>%
  check_code("j + 1")

If a student submits the following code:

# solution
j <- 0
for (i in 1:4) {
  if (i %% 2 == 0) {
    j <- j + 2
  }
}

It should highlight the j <- j + 2 part. Instead, however, the entire if loop is highlighted. Even though this is not wrong, it could be more specific.

Reproducible example in code

sol_code <- 'j <- 0
for (i in 1:4) {
  if (i %% 2 == 0) {
    j <- j + 1
  }
}
'

stu_code <- 'j <- 0
for (i in 1:4) {
  if (i %% 2 == 0) {
    j <- j + 2
  }
}
'

library(testwhat)
setup_state(sol_code = sol_code, stu_code = stu_code)

res <- run_until_fail(ex() %>% check_for() %>% check_body() %>% check_if_else() %>% check_if() %>% check_code('j + 1'))
payload <- testwhat:::post_process(res, ex_type="NormalExercise")
payload[c("line_start", "line_end", "column_start", "column_end")]

Results in:

$line_start
[1] 3

$line_end
[1] 5

$column_start
[1] 20

$column_end
[1] 3

While line_start and line_end should both be 4.