lint(text=) finds local settings again

NEWS.md

@@ -12,11 +12,12 @@
    + Linters `closed_curly_linter()`, `open_curly_linter()`, `paren_brace_linter()`, and `semicolon_terminator_linter()`.
 * Argument `interpret_glue` to `object_usage_linter()` is deprecated in favor of the more general `interpret_extensions`, in which `"glue"` is present by default (#1472, @MichaelChirico). See the description below.
 * The default for `pipe_consistency_linter()` is changed from `"auto"` (require one pipe style, either magrittr or native) to `"|>"` (R native pipe required) to coincide with the same change in the Tidyverse Style Guide (#2707, @MichaelChirico).
+* `lint()` no longer picks up settings automatically in _ad hoc_ invocations like `lint("text\n")` or `lint(text = "str")`. You should set `parse_settings=TRUE` to force settings to be read.
 
 ## Bug fixes
 
 * `Lint()`, and thus all linters, ensures that the returned object's `message` attribute is consistently a simple character string (and not, for example, an object of class `"glue"`; #2740, @MichaelChirico).
-* Files with encoding inferred from settings read more robustly under `lint(parse_settings = TRUE)` (#2803, @MichaelChirico).
+* Files with encoding inferred from settings read more robustly under `lint(parse_settings = TRUE)` (#2803, @MichaelChirico). Thanks also to @bastistician for detecting a regression caused by the initial change for users of Emacs (#2847).
 * `assignment_linter()` no longer errors if `"%<>%"` is an allowed operator (#2850, @AshesITR).
 * `condition_call_linter()` no longer covers cases where the object type in the ellipsis cannot be determined with certainty (#2888, #2890, @Bisaloo). In particular, this fixes the known false positive of custom conditions created via `errorCondition()` or `warningCondition()` not being compatible with the `call.` argument in `stop()` or `warning()`.
 

R/lint.R

@@ -45,7 +45,7 @@ lint <- function(filename, linters = NULL, ..., cache = FALSE, parse_settings =
 
   needs_tempfile <- missing(filename) || re_matches(filename, rex(newline))
   inline_data <- !is.null(text) || needs_tempfile
-  parse_settings <- !inline_data && isTRUE(parse_settings)
+  parse_settings <- (!inline_data || !missing(parse_settings)) && isTRUE(parse_settings)
 
   if (parse_settings) {
     read_settings(filename)
@@ -77,26 +77,7 @@ lint <- function(filename, linters = NULL, ..., cache = FALSE, parse_settings =
     return(exclude(lints, lines = lines, linter_names = names(linters), ...))
   }
 
-  file_linter_names <- names(linters)[vapply(linters, is_linter_level, logical(1L), "file")]
-  expression_linter_names <- names(linters)[vapply(linters, is_linter_level, logical(1L), "expression")]
-
-  lints <- list()
-  if (!is_tainted(source_expressions$lines)) {
-    for (expr in source_expressions$expressions) {
-      for (linter in necessary_linters(expr, expression_linter_names, file_linter_names)) {
-        # use withCallingHandlers for friendlier failures on unexpected linter errors
-        lints[[length(lints) + 1L]] <- withCallingHandlers(
-          get_lints(expr, linter, linters[[linter]], lint_cache, source_expressions$lines),
-          error = function(cond) {
-            cli_abort(
-              "Linter {.fn linter} failed in {.file {filename}}:",
-              parent = cond
-            )
-          }
-        )
-      }
-    }
-  }
+  lints <- lint_impl_(linters, lint_cache, filename, source_expressions)
 
   lints <- maybe_append_condition_lints(lints, source_expressions, lint_cache, filename)
   lints <- reorder_lints(flatten_lints(lints))
@@ -111,6 +92,33 @@ lint <- function(filename, linters = NULL, ..., cache = FALSE, parse_settings =
   zap_temp_filename(res, needs_tempfile)
 }
 
+lint_impl_ <- function(linters, lint_cache, filename, source_expressions) {
+  if (is_tainted(source_expressions$lines)) {
+    return(list())
+  }
+
+  file_linter_names <- names(linters)[vapply(linters, is_linter_level, logical(1L), "file")]
+  expression_linter_names <- names(linters)[vapply(linters, is_linter_level, logical(1L), "expression")]
+
+  lints <- list()
+  for (expr in source_expressions$expressions) {
+    for (linter in necessary_linters(expr, expression_linter_names, file_linter_names)) {
+      # use withCallingHandlers for friendlier failures on unexpected linter errors
+      lints[[length(lints) + 1L]] <- withCallingHandlers(
+        get_lints(expr, linter, linters[[linter]], lint_cache, source_expressions$lines),
+        error = function(cond) {
+          cli_abort(
+            "Linter {.fn linter} failed in {.file {filename}}:",
+            parent = cond
+          )
+        }
+      )
+    }
+  }
+
+  lints
+}
+
 #' @param path For the base directory of the project (for `lint_dir()`) or
 #'   package (for `lint_package()`).
 #' @param relative_path if `TRUE`, file paths are printed using their path relative to the base directory.

R/settings.R

@@ -65,6 +65,8 @@
 read_settings <- function(filename, call = parent.frame()) {
   reset_settings()
 
+  # doing lint(text=) should read settings from the current directory, required e.g. for Emacs, #2847
+  if (missing(filename)) filename <- "./any_local_file"
   config_file <- find_config(filename)
   default_encoding <- find_default_encoding(filename)
   if (!is.null(default_encoding)) {

tests/testthat/test-lint.R

@@ -279,3 +279,19 @@ test_that("gitlab_output() writes expected report", {
     ))
   )
 })
+
+test_that("explicit parse_settings=TRUE works for inline data", {
+  withr::local_dir(tempdir())
+  .lintr <- withr::local_tempfile(lines = "linters: list(assignment_linter())")
+  withr::local_options(list(lintr.linter_file = .lintr))
+
+  lint_str <- "a=1\n" # assignment lints, but not infix_spaces
+  foo <- withr::local_tempfile(lines = lint_str)
+
+  expect_length(lint(foo, parse_settings = TRUE), 1L)
+  expect_length(lint(text = lint_str, parse_settings = TRUE), 1L)
+  expect_length(lint(lint_str, parse_settings = TRUE), 1L)
+
+  # parse_settings=TRUE default not picked up
+  expect_length(lint(text = lint_str), 2L)
+})