chore(example tutorials): Better error messages when {gradethis} isn'…

…t installed (#802)
rstudio · Sep 27, 2023 · 0e1c0d6 · 0e1c0d6
1 parent 2859e0c
commit 0e1c0d6
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Showing 2 changed files with 15 additions and 9 deletions.
diff --git a/inst/examples/external/evaluator-tests.Rmd b/inst/examples/external/evaluator-tests.Rmd
@@ -6,6 +6,10 @@ runtime: shiny_prerendered
 
 ```{r setup, include=FALSE}
 library(learnr)
+if (!rlang::is_installed("gradethis")) {
+  stop("Please install `gradethis` from GitHub (rstudio/gradethis) for this example.")
+}
+
 knitr::opts_chunk$set(echo = FALSE)
 knitr::opts_chunk$set(exercise.checker = function(...){
   library(gradethis)
@@ -158,7 +162,7 @@ Enter the number 4, then click "Submit Answer" (**not Run Code**)
 3
 #4
 ```
- 
+
 ```{r excheck-check}
 gradethis::grade_result(
   gradethis::fail_if(~ identical(.result, 1), "Custom message for value 1."),
@@ -182,7 +186,7 @@ The following should work just as the previous example did. Click "Submit Answer
 3
 #4
 ```
- 
+
 ```{r excheck2-check}
 grade_result(
   fail_if(~ identical(.result, 1), "Custom message for value 1."),

diff --git a/inst/tutorials/sql-exercise/sql-exercise.Rmd b/inst/tutorials/sql-exercise/sql-exercise.Rmd
@@ -12,7 +12,9 @@ description: >
 
 ```{r setup, include=FALSE}
 library(learnr)
-# requires gradethis (>= 0.2.6.9000)
+if (!rlang::is_installed("gradethis", version = "0.2.6.9000")) {
+  stop("Please install `gradethis` from GitHub (rstudio/gradethis) for this example.")
+}
 library(gradethis)
 
 # Create an ephemeral in-memory RSQLite database
@@ -95,19 +97,19 @@ grade_this({
   .solution <- DBI::dbGetQuery(db_con, .solution_code)
 
   cols_expected <- c("name", "mpg", "cyl")
-  
+
   for (column in cols_expected) {
     if (!column %in% names(.result)) {
       fail("Did you forget to include `{column}`?")
     }
   }
-  
+
   extra_cols <- setdiff(names(.result), cols_expected)
   if (length(extra_cols)) {
     extra_cols <- knitr::combine_words(extra_cols, and = " or ", before = "`")
     fail("You don't need the columns {extra_cols}.")
   }
-  
+
   pass_if_equal(x = .result[cols_expected])
   fail()
 })
@@ -134,19 +136,19 @@ grade_this({
   .solution <- DBI::dbGetQuery(db_con, .solution_code)
 
   cols_expected <- c("name", "mpg", "cyl")
-  
+
   for (column in cols_expected) {
     if (!column %in% names(.result)) {
       fail("Did you forget to include `{column}`?")
     }
   }
-  
+
   extra_cols <- setdiff(names(.result), cols_expected)
   if (length(extra_cols)) {
     extra_cols <- knitr::combine_words(extra_cols, and = " or ", before = "`")
     fail("You don't need the columns {extra_cols}.")
   }
-  
+
   pass_if_equal(x = .result[cols_expected])
   fail()
 })