feat: parse --set H=/V= arguments

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/tests/wallp.bats b/tests/wallp.bats
index b5c9ff7..52e6706 100644
--- a/tests/wallp.bats
+++ b/tests/wallp.bats
@@ -127,3 +127,30 @@ teardown() {
   run pid_file_for V
   [ "$output" = "$HOME/.cache/wallp/V.pid" ]
 }
+
+@test "parse_set_args captures both" {
+  SET_H="" SET_V=""
+  parse_set_args "H=/a.png" "V=/b.png"
+  [ "$SET_H" = "/a.png" ]
+  [ "$SET_V" = "/b.png" ]
+}
+
+@test "parse_set_args partial leaves other empty" {
+  SET_H="" SET_V=""
+  parse_set_args "V=/only.png"
+  [ "$SET_H" = "" ]
+  [ "$SET_V" = "/only.png" ]
+}
+
+@test "parse_set_args expands tilde" {
+  SET_H="" SET_V=""
+  parse_set_args "H=~/x.png"
+  [ "$SET_H" = "$HOME/x.png" ]
+}
+
+@test "parse_set_args rejects unknown token" {
+  SET_H="" SET_V=""
+  run parse_set_args "Z=/bad.png"
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"Z="* ]]
+}
diff --git a/wallp b/wallp
index 0827fa4..128a155 100644
--- a/wallp
+++ b/wallp
@@ -120,6 +120,21 @@ pid_file_for() {
   esac
 }
 
+# Parse key=value conf into SET_* globals. Expands ~ in path values.
+# Rejects unknown tokens (not H= or V=).
+SET_H="" SET_V=""
+parse_set_args() {
+  local tok
+  for tok in "$@"; do
+    case "$tok" in
+      H=*) SET_H="$(expand_tilde "${tok#H=}")" ;;
+      V=*) SET_V="$(expand_tilde "${tok#V=}")" ;;
+      *) echo "wallp: unknown --set argument '$tok' (expected H=<file> or V=<file>)" >&2; return 1 ;;
+    esac
+  done
+  return 0
+}
+
 main() {
   return 0
 }