From c0ac77246e13ebbf30cd1cb317495c76897a4fd6 Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Wed, 2 Aug 2023 12:51:57 -0700
Subject: [PATCH] catch function calls in glue interpolation (#2033)

* catch function calls in glue interpolation

* extend test
---
 NEWS.md                                   |  1 +
 R/object_usage_linter.R                   |  2 +-
 tests/testthat/test-object_usage_linter.R | 13 +++++++++++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/NEWS.md b/NEWS.md
index 4cddc89bd..b60972245 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -7,6 +7,7 @@
 ## Changes to defaults
 
 * `assignment_linter()` lints the {magrittr} assignment pipe `%<>%` (#2008, @MichaelChirico). This can be deactivated by setting the new argument `allow_pipe_assign` to `TRUE`.
+* `object_usage_linter()` finds function usages inside `glue()` calls to avoid false positives for "unused objects" (#2029, @MichaelChirico).
 
 # lintr 3.1.0
 
diff --git a/R/object_usage_linter.R b/R/object_usage_linter.R
index 856b5e77a..93341f73d 100644
--- a/R/object_usage_linter.R
+++ b/R/object_usage_linter.R
@@ -223,7 +223,7 @@ symbol_extractor <- function(text, envir, data) {
   parse_data <- utils::getParseData(parsed_text)
 
   # strip backticked symbols; `x` is the same as x.
-  symbols <- gsub("^`(.*)`$", "\\1", parse_data$text[parse_data$token == "SYMBOL"])
+  symbols <- gsub("^`(.*)`$", "\\1", parse_data$text[parse_data$token %in% c("SYMBOL", "SYMBOL_FUNCTION_CALL")])
   for (sym in symbols) {
     assign(sym, NULL, envir = envir)
   }
diff --git a/tests/testthat/test-object_usage_linter.R b/tests/testthat/test-object_usage_linter.R
index bb29ecf96..9eea443eb 100644
--- a/tests/testthat/test-object_usage_linter.R
+++ b/tests/testthat/test-object_usage_linter.R
@@ -410,6 +410,19 @@ test_that("interprets glue expressions", {
       glue::glue('The answer is {local_var}.')
     }
   "), "local_var", object_usage_linter(interpret_glue = FALSE))
+
+  # call in glue is caught
+  expect_lint(
+    trim_some("
+      fun <- function() {
+        local_call <- identity
+        local_unused_call <- identity
+        glue::glue('{local_call(1)}')
+      }
+    "),
+    "local_unused_call",
+    linter
+  )
 })
 
 test_that("errors/edge cases in glue syntax don't fail lint()", {