Tests for trailing_blank_lines_linter() with chunks (#1614)

* Tests for `trailing_blank_lines_linter()` with chunks

Closes #741

* Use `library(withr)`

* formatting

* restructure

* Don't set `content` to `NULL`

* make it DAMP

* restructure to bring message closer to expectations

* use namespace

* use loadNamespace() for test-required packages

* Update test-trailing_blank_lines_linter.R

* Apply cleanup to the rest of the file

* same clean up in another test file

* Use `trim_some()`

Co-authored-by: Michael Chirico <chiricom@google.com>

R/trailing_blank_lines_linter.R

@@ -27,6 +27,7 @@ trailing_blank_lines_linter <- function() {
       }
       line_number <- line_number - 1L
     }
+
     if (identical(source_expression$terminal_newline, FALSE)) { # could use isFALSE, but needs backports
       last_line <- tail(source_expression$file_lines, 1L)
 
@@ -39,6 +40,7 @@ trailing_blank_lines_linter <- function() {
         line = last_line
       )
     }
+
     lints
   })
 }

tests/testthat.R

@@ -1,4 +1,6 @@
 library(testthat)
 library(lintr)
+loadNamespace("rex")
+loadNamespace("withr")
 
 test_check("lintr")

tests/testthat/test-knitr_formats.R

@@ -20,77 +20,77 @@ test_that("it handles dir", {
 
 test_that("it handles markdown", {
   expect_lint(
-    file = "knitr_formats/test.Rmd",
+    file = test_path("knitr_formats", "test.Rmd"),
     checks = list(
       list(regexes[["assign"]], line_number = 9L),
       list(regexes[["local_var"]], line_number = 22L),
       list(regexes[["assign"]], line_number = 22L),
       list(regexes[["trailing"]], line_number = 24L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles quarto", {
   expect_lint(
-    file = "knitr_formats/test.qmd",
+    file = test_path("knitr_formats", "test.qmd"),
     checks = list(
       list(regexes[["assign"]], line_number = 9L),
       list(regexes[["local_var"]], line_number = 22L),
       list(regexes[["assign"]], line_number = 22L),
       list(regexes[["trailing"]], line_number = 24L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles Sweave", {
   expect_lint(
-    file = "knitr_formats/test.Rnw",
+    file = test_path("knitr_formats", "test.Rnw"),
     checks = list(
       list(regexes[["assign"]], line_number = 12L),
       list(regexes[["local_var"]], line_number = 24L),
       list(regexes[["assign"]], line_number = 24L),
       list(regexes[["trailing"]], line_number = 26L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles reStructuredText", {
   expect_lint(
-    file = "knitr_formats/test.Rrst",
+    file = test_path("knitr_formats", "test.Rrst"),
     checks = list(
       list(regexes[["assign"]], line_number = 10L),
       list(regexes[["local_var"]], line_number = 23L),
       list(regexes[["assign"]], line_number = 23L),
       list(regexes[["trailing"]], line_number = 25L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles HTML", {
   expect_lint(
-    file = "knitr_formats/test.Rhtml",
+    file = test_path("knitr_formats", "test.Rhtml"),
     checks = list(
       list(regexes[["assign"]], line_number = 15L),
       list(regexes[["local_var"]], line_number = 27L),
       list(regexes[["assign"]], line_number = 27L),
       list(regexes[["trailing"]], line_number = 29L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles tex", {
   expect_lint(
-    file = "knitr_formats/test.Rtex",
+    file = test_path("knitr_formats", "test.Rtex"),
     checks = list(
       list(regexes[["assign"]], line_number = 11L),
       list(regexes[["local_var"]], line_number = 23L),
@@ -102,21 +102,21 @@ test_that("it handles tex", {
       # "%" as well.
       # cf. get_source_expressions("tests/testthat/knitr_formats/test.Rtex")$lines[[25]]
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
 
 test_that("it handles asciidoc", {
   expect_lint(
-    file = "knitr_formats/test.Rtxt",
+    file = test_path("knitr_formats", "test.Rtxt"),
     checks = list(
       list(regexes[["assign"]], line_number = 9L),
       list(regexes[["local_var"]], line_number = 22L),
       list(regexes[["assign"]], line_number = 22L),
       list(regexes[["trailing"]], line_number = 24L)
     ),
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 })
@@ -141,16 +141,16 @@ test_that("it does _not_ error with inline \\Sexpr", {
 
 test_that("it does lint .Rmd or .qmd file with malformed input", {
   expect_lint(
-    file = "knitr_malformed/incomplete_r_block.Rmd",
+    file = test_path("knitr_malformed", "incomplete_r_block.Rmd"),
     checks = "Missing chunk end",
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 
   expect_lint(
-    file = "knitr_malformed/incomplete_r_block.qmd",
+    file = test_path("knitr_malformed", "incomplete_r_block.qmd"),
     checks = "Missing chunk end",
-    default_linters,
+    linters = default_linters,
     parse_settings = FALSE
   )
 

tests/testthat/test-trailing_blank_lines_linter.R

@@ -1,35 +1,43 @@
-test_that("returns the correct linting", {
+test_that("trailing_blank_lines_linter doesn't block allowed usages", {
   linter <- trailing_blank_lines_linter()
-  msg <- rex::rex("Trailing blank lines are superfluous.")
-  msg2 <- rex::rex("Missing terminal newline.")
 
   expect_lint("blah", NULL, linter)
   expect_lint("blah <- 1  ", NULL, linter)
   expect_lint("blah <- 1\nblah", NULL, linter)
   expect_lint("blah <- 1\nblah\n \n blah", NULL, linter)
 
+  tmp <- withr::local_tempfile(lines = "lm(y ~ x)")
+  expect_lint(file = tmp, checks = NULL, linters = linter)
+})
+
+test_that("trailing_blank_lines_linter detects disallowed usages", {
+  linter <- trailing_blank_lines_linter()
+  msg <- rex::rex("Trailing blank lines are superfluous.")
+
   expect_lint("blah <- 1\n", msg, linter)
   expect_lint("blah <- 1\n  ", msg, linter)
-
   expect_lint("blah <- 1\n \n ", list(msg, msg), linter)
   expect_lint("blah <- 1\n\n", list(msg, msg), linter)
   expect_lint("blah <- 1\n\t\n", list(msg, msg), linter)
 
   # Construct a test file without terminal newline
   # cf. test-get_source_expressions.R
-  tmp <- withr::local_tempfile()
   tmp2 <- withr::local_tempfile()
-  cat("lm(y ~ x)\n", file = tmp)
   cat("lm(y ~ x)", file = tmp2)
+  expect_lint(
+    file = tmp2,
+    checks = list(
+      message = rex::rex("Missing terminal newline."),
+      line_number = 1L,
+      column_number = 10L
+    ),
+    linters = linter
+  )
+})
 
-  expect_lint(content = NULL, file = tmp, NULL, linter)
-  expect_lint(content = NULL, file = tmp2, list(
-    message = msg2,
-    line_number = 1L,
-    column_number = 10L
-  ), linter)
+test_that("trailing_blank_lines_linter detects missing terminal newlines in Rmd/qmd docs", {
+  linter <- trailing_blank_lines_linter()
 
-  # Construct an Rmd file without terminal newline
   tmp3 <- withr::local_tempfile(fileext = ".Rmd")
   cat(
     trim_some(
@@ -46,12 +54,16 @@ test_that("returns the correct linting", {
     ),
     file = tmp3
   )
-  expect_lint(content = NULL, file = tmp3, list(
-    message = msg2,
-    line_number = 10L,
-    # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
-    column_number = 1L
-  ), linter)
+  expect_lint(
+    file = tmp3,
+    checks = list(
+      message = rex::rex("Missing terminal newline."),
+      line_number = 10L,
+      # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
+      column_number = 1L
+    ),
+    linters = linter
+  )
 
   # Construct an Rmd file without R code (#1415)
   tmp4 <- withr::local_tempfile(fileext = ".Rmd")
@@ -65,12 +77,16 @@ test_that("returns the correct linting", {
     ),
     file = tmp4
   )
-  expect_lint(content = NULL, file = tmp4, list(
-    message = msg2,
-    line_number = 5L,
-    # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
-    column_number = 1L
-  ), linter)
+  expect_lint(
+    file = tmp4,
+    checks = list(
+      message = rex::rex("Missing terminal newline."),
+      line_number = 5L,
+      # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
+      column_number = 1L
+    ),
+    linters = linter
+  )
 
   # Construct a qmd file without terminal newline
   tmp5 <- withr::local_tempfile(fileext = ".qmd")
@@ -89,10 +105,66 @@ test_that("returns the correct linting", {
     ),
     file = tmp5
   )
-  expect_lint(content = NULL, file = tmp5, list(
-    message = msg2,
-    line_number = 10L,
-    # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
-    column_number = 1L
-  ), linter)
+  expect_lint(
+    file = tmp5,
+    checks = list(
+      message = rex::rex("Missing terminal newline."),
+      line_number = 10L,
+      # We can't get 4 here because the line is NA-masked in get_source_expressions(), so no line length info exists.
+      column_number = 1L
+    ),
+    linters = linter
+  )
+})
+
+test_that("blank lines in knitr chunks produce lints", {
+  linter <- trailing_blank_lines_linter()
+
+  tmp6 <- withr::local_tempfile(
+    fileext = ".Rmd",
+    lines = trim_some(
+      '---
+      title: "Some file"
+      ---
+
+      ```{r}
+      abc = 123
+
+      ```
+      \n'
+    )
+  )
+
+  expect_lint(
+    file = tmp6,
+    checks = list(message = rex::rex("Trailing blank lines are superfluous."), line_number = 7L, column_number = 1L),
+    linters = linter
+  )
+
+  tmp7 <- withr::local_tempfile(
+    fileext = ".qmd",
+    lines = trim_some(
+      '---
+      title: "Some file"
+      ---
+
+      ```{r}
+      abc = 123
+
+
+
+      ```
+      \n'
+    )
+  )
+
+  expect_lint(
+    file = tmp7,
+    checks = list(
+      list(message = rex::rex("Trailing blank lines are superfluous."), line_number = 7L, column_number = 1L),
+      list(message = rex::rex("Trailing blank lines are superfluous."), line_number = 8L, column_number = 1L),
+      list(message = rex::rex("Trailing blank lines are superfluous."), line_number = 9L, column_number = 1L)
+    ),
+    linters = linter
+  )
 })