Most of `grab_` and `plot_` functions don't work if `generate_placebos = FALSE`

Hello, I think I found a bug that is present on the Github version but not on CRAN version. When I use generate_placebos = FALSE in synthetic_control(), then most of the grab_ and plot_ functions don't work:

library(tidysynth)

smoking_out <- smoking %>%
  synthetic_control(
    outcome = cigsale, 
    unit = state, 
    time = year,
    i_unit = "California", 
    i_time = 1988, 
    generate_placebos = FALSE 
  ) %>%

  generate_predictor(
    time_window = 1980:1988,
    ln_income = mean(lnincome, na.rm = T)
  ) %>%
  generate_weights(optimization_window = 1970:1988) %>%
  generate_control()

smoking_out %>% grab_outcome()
#> # A tibble: 0 × 1
#> # … with 1 variable: .outcome <???>
#> # ℹ Use `colnames()` to see all variable names

smoking_out %>% grab_predictors()
#> # A tibble: 0 × 1
#> # … with 1 variable: .predictors <???>
#> # ℹ Use `colnames()` to see all variable names

smoking_out %>% grab_unit_weights()
#> # A tibble: 0 × 1
#> # … with 1 variable: .unit_weights <???>
#> # ℹ Use `colnames()` to see all variable names

smoking_out %>% grab_predictor_weights()
#> # A tibble: 0 × 1
#> # … with 1 variable: .predictor_weights <???>
#> # ℹ Use `colnames()` to see all variable names

smoking_out %>% grab_loss()
#> # A tibble: 1 × 4
#>   .id     .placebo variable_mspe control_unit_mspe
#>   <chr>      <dbl>         <dbl>             <dbl>
#> 1 Alabama        1          149.         0.0000257

smoking_out %>% grab_significance()
#> # A tibble: 1 × 8
#>   unit_name type  pre_mspe post_mspe mspe_ratio  rank fishers_exact_pv…¹ z_score
#>   <chr>     <chr>    <dbl>     <dbl>      <dbl> <int>              <dbl>   <dbl>
#> 1 Alabama   Donor     149.      11.1     0.0744     1                  1      NA
#> # … with abbreviated variable name ¹fishers_exact_pvalue

smoking_out %>% grab_balance_table()
#> Error in `chr_as_locations()`:
#> ! Can't subset columns that don't exist.
#> ✖ Column `variable` doesn't exist.

smoking_out %>% grab_synthetic_control()
#> # A tibble: 0 × 1
#> # … with 1 variable: .synthetic_control <???>
#> # ℹ Use `colnames()` to see all variable names

smoking_out %>% plot_trends()
#> Error in `dplyr::filter()`:
#> ! Problem while computing `..1 = time_unit %in% time_window`.
#> Caused by error in `time_unit %in% time_window`:
#> ! object 'time_unit' not found

smoking_out %>% plot_differences()
#> Error in `dplyr::mutate()`:
#> ! Problem while computing `diff = real_y - synth_y`.
#> Caused by error in `mask$eval_all_mutate()`:
#> ! object 'real_y' not found

smoking_out %>% plot_weights()
#> Error in `chr_as_locations()`:
#> ! Can't rename columns that don't exist.
#> ✖ Column `variable` doesn't exist.

^{Created on 2022-08-31 by the reprex package (v2.0.1)}

Everything works correctly if generate_placebos = TRUE but it makes the function slower and placebos shouldn't be needed for these functions.

Besides this bug, even the output of generate_control() seems weird when generate_placebos = FALSE:

library(tidysynth)

smoking_out <- smoking %>%
  synthetic_control(
    outcome = cigsale, 
    unit = state, 
    time = year,
    i_unit = "California", 
    i_time = 1988, 
    generate_placebos = FALSE 
  ) %>%

  generate_predictor(
    time_window = 1980:1988,
    ln_income = mean(lnincome, na.rm = T)
  ) %>%
  generate_weights(optimization_window = 1970:1988) %>%
  generate_control()

smoking_out
#> # A tibble: 2 × 11
#>   .id     .placebo .type   .outcome .predi…¹ .synth…² .unit_…³ .predi…⁴ .origi…⁵
#>   <chr>      <dbl> <chr>   <list>   <list>   <list>   <list>   <list>   <list>  
#> 1 Alabama        1 treated <tibble> <tibble> <tibble> <tibble> <tibble> <tibble>
#> 2 Alabama        1 contro… <tibble> <tibble> <tibble> <tibble> <tibble> <tibble>
#> # … with 2 more variables: .meta <list>, .loss <list>, and abbreviated variable
#> #   names ¹.predictors, ².synthetic_control, ³.unit_weights,
#> #   ⁴.predictor_weights, ⁵.original_data
#> # ℹ Use `colnames()` to see all variable names

^{Created on 2022-08-31 by the reprex package (v2.0.1)} Can you confirm that it works as expected?

edunford / tidysynth

Most of `grab_` and `plot_` functions don't work if `generate_placebos = FALSE` #20