first pass at implementing a backport_linter

DESCRIPTION

@@ -45,6 +45,7 @@ Collate:
     'addins.R'
     'assignment_linter.R'
     'assignment_spaces_linter.R'
+    'backport_linter.R'
     'cache.R'
     'closed_curly_linter.R'
     'commas_linter.R'

NEWS.md

@@ -24,6 +24,7 @@
 * `spaces_inside_linter` ignores spaces preceding trailing comments (#636, @michaelchirico)
 * `T_and_F_symbol_linter` is now part of the default linters (#517, #612, @AshesITR)
 * `with_defaults()` no longer duplicates the `lintr_function` class when it is already present (#511, #612, @AshesITR)
+* New `backport_linter()` for detecting mismatched R version dependencies (#506, @MichaelChirico)
 * `paren_brace_linter` and `no_tab_linter` also use more reliable matching (e.g.,
   excluding matches found in comments; #441 and #545, @russHyde)
 

R/backport_linter.R

@@ -0,0 +1,86 @@
+#' @describeIn linters that checks for usage of unavailable functions. Not reliable for testing r-devel dependencies.
+#' @export
+backport_linter <- function(r_version = getRversion()) {
+  function(source_file) {
+    if (inherits(r_version, "numeric_version")) r_version <- format(r_version)
+    if (r_version < "3.0.0") {
+      warning("It is not recommended to depend on an R version older than 3.0.0. Resetting 'r_version' to 3.0.0.")
+      r_version <- "3.0.0"
+    }
+    if (is.null(source_file$xml_parsed_content)) return(list())
+
+    xml <- source_file$xml_parsed_content
+
+    names_xpath <- "//*[self::SYMBOL or self::SYMBOL_FUNCTION_CALL]"
+    all_names_nodes <- xml2::xml_find_all(xml, names_xpath)
+    all_names <- xml2::xml_text(all_names_nodes)
+
+    # guaranteed to include 1 by early return above; which.min fails if all TRUE (handled by nomatch)
+    needs_backport_names <- backports[1:(match(FALSE, r_version < names(backports), nomatch = length(backports)) - 1L)]
+
+    # not sapply/vapply, which may over-simplify to vector -- cbind makes sure we have a matrix so rowSums works
+    needs_backport <- do.call(cbind, lapply(needs_backport_names, function(nm) all_names %in% nm))
+    bad_idx <- rowSums(needs_backport) > 0L
+
+    lapply(which(bad_idx), function(ii) {
+      node <- all_names_nodes[[ii]]
+      line1 <- xml2::xml_attr(node, "line1")
+      col1 <- as.integer(xml2::xml_attr(node, "col1"))
+      if (xml2::xml_attr(node, "line2") == line1) {
+        col2 <- as.integer(xml2::xml_attr(node, "col2"))
+      } else {
+        col2 <- nchar(source_file$lines[line1])
+      }
+      Lint(
+        filename = source_file$filename,
+        line_number = as.integer(line1),
+        column_number = col1,
+        type = "warning",
+        message = sprintf(
+          "%s (R %s) is not available for dependency R >= %s.",
+          all_names[ii], names(needs_backport_names)[which(needs_backport[ii, ])], r_version
+        ),
+        line = source_file$lines[[line1]],
+        ranges = list(c(col1, col2)),
+        linter = "backport_linter"
+      )
+    })
+  }
+}
+
+backports <- list(
+  `devel` = c("...names", "checkRdContents", "numToBits", "numToInts", "packBits"),
+  `4.0.0` = c(
+    ".class2", ".S3method", "activeBindingFunction", "deparse1", "globalCallingHandlers",
+    "infoRDS", "list2DF", "marginSums", "proportions", "R_user_dir", "socketTimeout", "tryInvokeRestart"
+  ),
+  `3.6.0` = c(
+    "asplit", "hcl.colors", "hcl.pals", "mem.maxNsize", "mem.maxVsize", "nullfile", "str2lang",
+    "str2expression", "update_PACKAGES"
+  ),
+  `3.5.0` = c("...elt", "...length", "askYesNo", "getDefaultCluster", "isFALSE", "packageDate", "warnErrList"),
+  `3.4.0` = c(
+    "check_packages_in_dir_details", "CRAN_package_db", "debugcall", "hasName",
+    "isS3stdgeneric", "strcapture", "Sys.setFileTime", "undebugcall"
+  ),
+  `3.3.0` = c(
+    ".traceback", "chkDots", "curlGetHeaders", "endsWith", "grouping", "isS3method",
+    "makevars_site", "makevars_user", "Rcmd", "sigma", "startsWith", "strrep", "validEnc", "validUTF8"
+  ),
+  `3.2.0` = c(
+    ".getNamespaceInfo", "check_packages_in_dir_changes", "debuggingState",
+    "dir.exists", "dynGet", "extSoftVersion", "get0", "grSoftVersion", "hsearch_db",
+    "isNamespaceLoaded", "lengths", "libcurlVersion", "returnValue", "tclVersion", "toTitleCase", "trimws"
+  ),
+  `3.1.3` = "pcre_config",
+  `3.1.2` = "icuGetCollate",
+  `3.1.1` = c(".nknots.smspl", "promptImport"),
+  `3.1.0` = c("agrepl", "anyNA", "changedFiles", "cospi", "fileSnapshot", "find_gs_cmd", "sinpi", "tanpi"),
+  `3.0.3` = "La_version",
+  `3.0.2` = c("assertCondition", "assertError", "assertWarning", "getVignetteInfo"),
+  `3.0.0` = c(
+    ".onDetach", "bitwAnd", "bitwNot", "bitwOr", "bitwShiftL", "bitwShiftR", "bitwXor",
+    "check_packages_in_dir", "cite", "citeNatbib", "clearPushBack", "packageName",
+    "process.events", "provideDimnames", "quartz.save", "rep_len"
+  )
+)

tests/testthat/test-backport_linter.R

@@ -0,0 +1,32 @@
+test_that("backport_linter detects backwards-incompatibility", {
+  # default should be current R version; all of these are included on our dependency
+  expect_lint(".getNamespaceInfo(dir.exists(lapply(x, toTitleCase)))", NULL, backport_linter())
+
+  # don't allow dependencies older than we've recorded
+  writeLines("x <- x + 1", tmp <- tempfile())
+  on.exit(unlink(tmp))
+
+  expect_warning(l <- lint(tmp, backport_linter("2.0.0")), "version older than 3.0.0", fixed = TRUE)
+  expect_identical(l, lint(tmp, backport_linter("3.0.0")))
+
+  expect_lint(
+    "numToBits(2)",
+    rex("numToBits (R devel) is not available for dependency R >= 4.0.0."),
+    backport_linter("4.0.0")
+  )
+  # symbols as well as calls
+  expect_lint(
+    "lapply(1:10, numToBits)",
+    rex("numToBits (R devel) is not available for dependency R >= 4.0.0."),
+    backport_linter("4.0.0")
+  )
+
+  expect_lint(
+    "trimws(...names())",
+    list(
+      rex("trimws (R 3.2.0) is not available for dependency R >= 3.0.0."),
+      rex("...names (R devel) is not available for dependency R >= 3.0.0.")
+    ),
+    backport_linter("3.0.0")
+  )
+})