perf(build-newer-r): skip packages that already have a binary in bulk

Decide the already-built candidates from one listing per slot and one ABI-verdict query instead of a DB connection and several S3 requests per package; anything undecidable still goes through bincraft.

local/tests/test-newer-r-helpers.R

@@ -1,4 +1,5 @@
 source(file.path("..", "newer-r-helpers.R"))
+source(file.path("..", "rebuild-missing-helpers.R"))
 
 test_that("R constraints respect patch versions, bounds, and missing fields", {
   expect_true(r_requirement_satisfied(NA_character_, "4.4.3"))
@@ -79,3 +80,70 @@ test_that("R-devel Recommended copies cannot block ordinary CRAN dependencies",
     c("arules", "arulesSequences", "indirect")
   )
 })
+
+candidates <- function() {
+  data.frame(
+    Package = c(
+      "flat_done",
+      "flat_todo",
+      "minor_done",
+      "minor_flat_only",
+      "unclassified",
+      "fallback"
+    ),
+    Version = c("1.0", "1.0", "2.0", "2.0", "3.0", "4.0")
+  )
+}
+
+verdicts <- c(
+  flat_done_1.0 = FALSE,
+  flat_todo_1.0 = FALSE,
+  minor_done_2.0 = TRUE,
+  minor_flat_only_2.0 = TRUE,
+  fallback_4.0 = FALSE
+)
+
+flat <- c(
+  flat_done_1.0.tar.gz = "aaa",
+  minor_flat_only_2.0.tar.gz = "bbb",
+  unclassified_3.0.tar.gz = "ccc",
+  fallback_4.0.tar.gz = "c0ffee"
+)
+minor <- c(minor_done_2.0.tar.gz = "ddd")
+md5 <- c(fallback_4.0 = "c0ffee")
+
+test_that("newer_r_outstanding skips only binaries at the routed path", {
+  expect_identical(
+    newer_r_outstanding(candidates(), verdicts, flat, minor, md5)$Package,
+    # flat_todo: absent; minor_flat_only: sensitive, so a flat copy does not
+    # count; unclassified: no verdict, left to bincraft; fallback: CRAN source
+    c("flat_todo", "minor_flat_only", "unclassified", "fallback")
+  )
+})
+
+test_that("newer_r_outstanding keeps a route whose slot could not be listed", {
+  expect_identical(
+    newer_r_outstanding(candidates(), verdicts, NULL, minor, md5)$Package,
+    c("flat_done", "flat_todo", "minor_flat_only", "unclassified", "fallback")
+  )
+  expect_identical(
+    newer_r_outstanding(candidates(), verdicts, flat, NULL, md5)$Package,
+    c("flat_todo", "minor_done", "minor_flat_only", "unclassified", "fallback")
+  )
+})
+
+test_that("newer_r_outstanding without verdicts or listings changes nothing", {
+  expect_identical(
+    newer_r_outstanding(candidates(), logical(), flat, minor, md5),
+    candidates()
+  )
+  empty <- stats::setNames(character(), character())
+  expect_identical(
+    nrow(newer_r_outstanding(candidates(), verdicts, empty, empty, md5)),
+    nrow(candidates())
+  )
+  expect_identical(
+    nrow(newer_r_outstanding(candidates()[0L, ], verdicts, flat, minor, md5)),
+    0L
+  )
+})