From ac7344cd0058a8fb0ba2987294069ce2c601784a Mon Sep 17 00:00:00 2001
From: wlandau <will.landau.oss@gmail.com>
Date: Fri, 8 Nov 2024 12:32:00 -0500
Subject: [PATCH] refactor junction a bit

---
 R/class_junction.R                   |  8 ++++++++
 R/class_outdated.R                   |  3 +--
 R/class_pattern.R                    |  2 +-
 R/class_stem.R                       |  2 +-
 tests/testthat/test-class_junction.R | 11 +++++++++++
 5 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/R/class_junction.R b/R/class_junction.R
index c58f734cb..34867e688 100644
--- a/R/class_junction.R
+++ b/R/class_junction.R
@@ -23,6 +23,10 @@ junction_upstream_edges <- function(junction) {
   data_frame(from = from, to = to)
 }
 
+junction_get_splits <- function(junction) {
+  as.character(junction$splits)
+}
+
 junction_transpose <- function(junction) {
   splits <- junction$splits
   deps <- junction$deps
@@ -34,6 +38,10 @@ junction_transpose <- function(junction) {
   out
 }
 
+junction_invalidate <- function(junction) {
+  junction$splits <- rep(NA_character_, length(junction$splits))
+}
+
 junction_validate_deps <- function(deps) {
   if (!is.null(deps) && !is.data.frame(deps)) {
     tar_throw_validate("deps field of junction must be null or a data frame.")
diff --git a/R/class_outdated.R b/R/class_outdated.R
index 4191c54f0..c009ead4f 100644
--- a/R/class_outdated.R
+++ b/R/class_outdated.R
@@ -104,8 +104,7 @@ outdated_class <- R6::R6Class(
     },
     reset_junction = function(target) {
       if (!is.null(target$junction)) {
-        new_splits <- rep(NA_character_, length(target$junction$splits))
-        target$junction$splits <- new_splits
+        junction_invalidate(target$junction)
       }
     },
     register_checked = function(name) {
diff --git a/R/class_pattern.R b/R/class_pattern.R
index d74b197cb..bd3e4ad81 100644
--- a/R/class_pattern.R
+++ b/R/class_pattern.R
@@ -44,7 +44,7 @@ pattern_s3_class <- c("tar_pattern", "tar_target")
 
 #' @export
 target_get_children.tar_pattern <- function(target) {
-  as.character(target$junction$splits)
+  junction_get_splits(target$junction)
 }
 
 #' @export
diff --git a/R/class_stem.R b/R/class_stem.R
index 6da77d885..f28023afc 100644
--- a/R/class_stem.R
+++ b/R/class_stem.R
@@ -47,7 +47,7 @@ target_get_children.tar_stem <- function(target) {
   if_any(
     is.null(target$junction),
     character(0),
-    target$junction$splits
+    junction_get_splits(target$junction)
   )
 }
 
diff --git a/tests/testthat/test-class_junction.R b/tests/testthat/test-class_junction.R
index 5dc7374f9..8f35e46ba 100644
--- a/tests/testthat/test-class_junction.R
+++ b/tests/testthat/test-class_junction.R
@@ -5,6 +5,17 @@ tar_test("junction deps", {
   expect_equal(out, exp)
 })
 
+tar_test("junction_get_splits()", {
+  x <- junction_init("x", letters, list(a = LETTERS, b = rev(letters)))
+  expect_equal(junction_get_splits(x), letters)
+})
+
+tar_test("junction_invalidate()", {
+  x <- junction_init("x", letters, list(a = LETTERS, b = rev(letters)))
+  junction_invalidate(x)
+  expect_equal(junction_get_splits(x), rep(NA_character_, length(x$splits)))
+})
+
 tar_test("junction_upstream_edges()", {
   names <-  paste0("child_", seq_len(3))
   x <- paste0("x_", seq_len(3))