From 4a7445fd06b59881548ac5f6ce4e0c1693364af3 Mon Sep 17 00:00:00 2001
From: rgodden <7768980+goddenrich@users.noreply.github.com>
Date: Wed, 28 Jan 2026 12:41:50 +0000
Subject: [PATCH] test showing bug with whatinputs

---
 src/query/whatinputs_test.go         | 13 +++++++++++++
 test/whatinputs/BUILD                |  7 +++++++
 test/whatinputs/test_package/BUILD   | 14 ++++++++++++++
 test/whatinputs/test_package/bar.txt |  0
 4 files changed, 34 insertions(+)
 create mode 100644 test/whatinputs/test_package/bar.txt

diff --git a/src/query/whatinputs_test.go b/src/query/whatinputs_test.go
index 09e82712b7..51fc10958f 100644
--- a/src/query/whatinputs_test.go
+++ b/src/query/whatinputs_test.go
@@ -88,3 +88,16 @@ func TestWhatInputsSourceBothTargetsHidden(t *testing.T) {
 	inputLabels := whatInputs(graph.AllTargets(), "package1/file1.txt", true)
 	assert.Equal(t, []core.BuildLabel{{PackageName: "package1", Name: "_target1#srcs"}, {PackageName: "package1", Name: "target1"}}, inputLabels)
 }
+
+func TestWhatInputsSingleTargetParentUnderscore(t *testing.T) {
+	graph := core.NewGraph()
+	pkg := core.NewPackage("package1")
+	fileSource := core.FileLabel{File: "file1.txt", Package: pkg.Name}
+	internalTarget := addNewTarget(graph, pkg, "__target1#srcs", []core.BuildInput{fileSource})
+	addNewTarget(graph, pkg, "_target1", []core.BuildInput{fileSource, internalTarget.Label})
+	graph.AddPackage(pkg)
+
+	inputLabels := whatInputs(graph.AllTargets(), "package1/file1.txt", false)
+	assert.Equal(t, []core.BuildLabel{{PackageName: "package1", Name: "_target1"}}, inputLabels)
+}
+
diff --git a/test/whatinputs/BUILD b/test/whatinputs/BUILD
index 9fa9bd96cb..5fc303e0dc 100644
--- a/test/whatinputs/BUILD
+++ b/test/whatinputs/BUILD
@@ -7,6 +7,13 @@ plz_e2e_test(
     expected_output = "multiple_sources.txt",
 )
 
+plz_e2e_test(
+    name = "hidden_targets",
+    cmd = "plz query whatinputs test/whatinputs/test_package/bar.txt",
+    expected_failure = False,
+    expect_output_contains = "//test/whatinputs/test_package:_target2",
+)
+
 plz_e2e_test(
     name = "source_and_no_source",
     cmd = "plz query whatinputs making/up/a/file/path/should/be/easy test/whatinputs/test_package/foo.txt",
diff --git a/test/whatinputs/test_package/BUILD b/test/whatinputs/test_package/BUILD
index 18ebe28f93..2ed10830f8 100644
--- a/test/whatinputs/test_package/BUILD
+++ b/test/whatinputs/test_package/BUILD
@@ -4,3 +4,17 @@ genrule(
     outs = ["out.txt"],
     cmd = "cat $SRCS > $OUT",
 )
+
+genrule(
+    name = "_target2",
+    srcs = ["_target2#child"],
+    outs = ["out2.txt"],
+    cmd = "cat $SRCS > $OUT",
+)
+
+genrule(
+    name = "_target2#child",
+    srcs = ["bar.txt"],
+    outs = ["out2_child.txt"],
+    cmd = "cat $SRCS > $OUT",
+)
diff --git a/test/whatinputs/test_package/bar.txt b/test/whatinputs/test_package/bar.txt
new file mode 100644
index 0000000000..e69de29bb2