Don't auto-link fs_path values inside link targets

NEWS.md

@@ -1,5 +1,9 @@
 # cli (development version)
 
+* Interpolating an `fs_path` (or any object mapped to the `file` style via
+  the theme's `class-map`) into the target of a link, e.g.
+  `{.run [text]({path})}`, no longer corrupts the link's URL (#683).
+
 * `keypress()` improvements:
   - `timeout` argument to wait at most a given number of seconds for a
     key press.

R/inline.R

@@ -191,10 +191,16 @@ inline_transformer <- function(code, envir) {
       id <- NULL
     }
 
+    # Don't apply implicit `class-map` styling (e.g. `fs_path` -> `file`)
+    # inside URL-building link containers
+    in_link <- any(vlapply(app$doc, function(x) {
+      any(x$class %in% c("run", "href", "help", "topic", "vignette"))
+    }))
+
     rcls <- class(val)
     stls <- app$get_current_style()$`class-map`
     cls <- na.omit(match(rcls, names(stls)))[1]
-    if (!is.na(cls)) {
+    if (!is.na(cls) && !in_link) {
       class <- c(class, stls[[cls]])
     }
 

tests/testthat/test-links.R

@@ -236,6 +236,34 @@ test_that_cli(configs = "plain", links = "all", ".run with custom format", {
   })
 })
 
+test_that("fs_path is not auto-linked inside a link target (#683)", {
+  withr::local_options(
+    cli.hyperlink = TRUE,
+    cli.hyperlink_run = TRUE
+  )
+
+  # fs_path values must not be implicitly styled as files when they are
+  # substituted into a link target, as the embedded file link would
+  # corrupt the target URL.
+  path <- structure("~/foo.R", class = c("fs_path", "character"))
+  chr <- "~/foo.R"
+
+  # the target should be identical to the plain-character case
+  expect_equal(
+    format_inline("{.run ['hi mom']({path})}"),
+    format_inline("{.run ['hi mom']({chr})}")
+  )
+  expect_equal(
+    format_inline("{.run ['file.R'](pkgdown::preview_page('{path}'))}"),
+    format_inline("{.run ['file.R'](pkgdown::preview_page('{chr}'))}")
+  )
+
+  # and the target must not contain a nested (file) hyperlink
+  out <- format_inline("{.run ['hi mom']({path})}")
+  expect_match(out, "x-r-run:~/foo.R", fixed = TRUE)
+  expect_false(grepl("file://", out, fixed = TRUE))
+})
+
 # -- {.topic} -------------------------------------------------------------
 
 test_that_cli(configs = "plain", links = c("all", "none"), "{.topic}", {