Add formatter_cli

DESCRIPTION

@@ -22,6 +22,7 @@ Imports:
     utils
 Suggests:
     botor,
+    cli,
     covr,
     crayon,
     devtools,

NAMESPACE

@@ -32,6 +32,7 @@ export(colorize_by_log_level)
 export(delete_logger_index)
 export(deparse_to_one_line)
 export(fail_on_missing_package)
+export(formatter_cli)
 export(formatter_glue)
 export(formatter_glue_or_sprintf)
 export(formatter_glue_safe)

NEWS.md

@@ -7,6 +7,7 @@
 * `log_appender()`, `log_layout()` and `log_formatter()` now check that you are calling them with a function, and return the previously set value (#170, @hadley)
 * new function to return number of log indices (#194, @WurmPeter)
 * `appender_async` is now using `mirai` instead of a custom background process and queue system (#214, @hadley @shikokuchuo)
+* New `formatter_cli()` allows you to use the syntax from the cli package to create log messages (#210, @thomasp85)
 
 ## Fixes
 

R/formatters.R

@@ -173,6 +173,36 @@
 }
 attr(formatter_glue_or_sprintf, "generator") <- quote(formatter_glue_or_sprintf())
 
+#' Apply [cli::cli_text()] to format string with cli syntax
+#' @param ... passed to [cli::cli_text()] for the text interpolation
+#' @inheritParams log_level
+#' @return character vector
+#' @export
+#' @family log_formatters
+#' @importFrom utils str
+formatter_cli <- function(...,
+                          .logcall = sys.call(),
+                          .topcall = sys.call(-1),
+                          .topenv = parent.frame()) {
+  fail_on_missing_package("cli")
+
+  withCallingHandlers(
+    cli::cli_fmt(cli::cli_text(..., .envir = .topenv)),
+    error = function(e) {
+      args <- paste0(capture.output(str(...)), collapse = "\n")
+
+      stop(paste0(
+        "`cli` failed in `formatter_cli` on:\n\n",
+        args,
+        "\n\nRaw error message:\n\n",
+        conditionMessage(e),
+        "\n\nPlease consider using another `log_formatter` or ",
+        "`skip_formatter` on strings with curly braces."
+      ))
+    }
+  )
+}
+attr(formatter_cli, "generator") <- quote(formatter_cli())
 
 #' Transforms all passed R objects into a JSON list
 #' @param ... passed to `toJSON` wrapped into a `list`

tests/testthat/test-formatters.R

@@ -109,6 +109,29 @@ test_that("glue+sprintf works", {
   }
 })
 
+test_that("cli works", {
+  local_test_logger(formatter = formatter_cli)
+
+  a <- 43
+
+  expect_equal(formatter_cli("Hi"), "Hi")
+  expect_equal(formatter_cli("{.arg Hi}"), "`Hi`")
+  expect_equal(formatter_cli("1 + {1}"), "1 + 1")
+  expect_equal(formatter_cli("{1:2}"), "1 and 2")
+  expect_equal(formatter_cli("pi is {round(pi, 2)}"), "pi is 3.14")
+  expect_equal(formatter_cli("Hi {42}"), "Hi 42")
+  expect_equal(formatter_cli("Hi {1:2}"), paste("Hi 1 and 2"))
+
+  expect_output(do.call(logger, namespaces$global[[1]])(INFO, 42), "42")
+  expect_output(do.call(logger, namespaces$global[[1]])(INFO, "Hi {a}"), "43")
+
+  expect_equal(formatter_cli("Hi {a}"), "Hi 43")
+  expect_output(log_info("Hi {a}"), "43")
+  expect_output(log_warn("Hi {a}"), "43")
+  f <- function() log_info("Hi {a}")
+  expect_output(f(), "43")
+})
+
 test_that("formatter_logging works", {
   local_test_logger(formatter = formatter_logging)