Improve object cleanup

NEWS.md

@@ -1,5 +1,9 @@
 # pool (development version)
 
+* If you `poolCheckout()` an object and forget to return it before it's deleted,
+  you now get a more informative message and the object is automatically 
+  cleaned up (#95).
+
 # pool 0.1.6
 
 * `left_join()` and friends once again work with pool objects (#111).

R/pool.R

@@ -179,7 +179,9 @@ Pool <- R6::R6Class("Pool",
       ## detect leaked connections and destroy them
       reg.finalizer(pool_metadata, function(e) {
         if (pool_metadata$valid) {
-          warning("You have a leaked pooled object.")
+          cat("<pool> Checked-out object deleted before being returned.\n")
+          cat("<pool> Make sure to `poolReturn()` all objects retrieved with `poolCheckout().`\n")
+          self$release(object)
         }
       }, onexit = TRUE)
 

tests/testthat/_snaps/release.md

@@ -0,0 +1,13 @@
+# release: warns if object can't be returned
+
+    Code
+      pool <- poolCreate(function() 1)
+      obj <- poolCheckout(pool)
+      rm(obj)
+      . <- gc()
+    Output
+      <pool> Checked-out object deleted before being returned.
+      <pool> Make sure to `poolReturn()` all objects retrieved with `poolCheckout().`
+    Code
+      poolClose(pool)
+

tests/testthat/test-release.R

@@ -64,6 +64,17 @@ describe("release", {
     expect_error(poolClose(pool),
       "The pool was already closed.")
   })
+
+  it("warns if object can't be returned", {
+    expect_snapshot({
+      pool <- poolCreate(function() 1)
+      obj <- poolCheckout(pool)
+      rm(obj)
+      . <- gc()
+      poolClose(pool)
+    })
+  })
+
 })