improvise-29w2: a CLOSED PR the loop waits on (MERGEABLE/BLOCKED) pins the state check at the loop top

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

context/code/tooling.md

@@ -286,8 +286,13 @@ The rule now:
   already merged, and can come mid-wait when someone merges it during the watch.
   A merged PR reports `UNKNOWN/UNKNOWN` permanently (#189, read live), so the
   UNKNOWN wait slept the whole timeout there and then blamed mergeability. A
-  closed one need not: #74 reads `CONFLICTING/DIRTY`, which already ended the
-  wait, but as a misleading exit 1. The script now fetches `state`. Exit 5 is
+  closed PR's mergeability is whatever it was when it closed, so it can land on
+  either side of the wait. #74 reads `CONFLICTING/DIRTY`, which ends the loop at
+  once, but as a misleading exit 1. #46 has green checks and reads
+  `MERGEABLE/BLOCKED`, which the loop waits on, so it slept the full timeout
+  too (improvise-29w2). The suite carries all three shapes, and only the
+  waited-on ones can tell whether the state is checked at the top of the loop.
+  The script now fetches `state`. Exit 5 is
   its own code, not 1 or 0, because under merge-as-soon-as-green "someone else
   already merged it" is a normal answer, and the caller should hear it as that.
 - **The head checks come first, and the ended check after them**

context/test-evidence/tooling.md

@@ -718,6 +718,19 @@ Two rivals:
 - **Exit 1 instead of 5.** Both exit-code cases fail with exit 1. That keeps
   "already merged" apart from "not mergeable".
 
+**29w2: the CLOSED cases could not discriminate.** Found reviewing #253 at
+`8cdea3a4`. The only CLOSED shape was #74's `CONFLICTING/DIRTY`, and that ends
+the loop on the first poll whether or not the state is checked there. So
+**rival R8** passed 52 of 52. R8 exits 5 for MERGED at the loop top, but for
+CLOSED only after the loop breaks. Run live against #46 with `--timeout 15`, R8
+exited 3 and `8cdea3a4` exited 5. A third shape is added, #46's: CLOSED, green
+checks, `MERGEABLE/BLOCKED`, which the loop waits on. #74's shape stays.
+
+- **R8:** both new cases fail, the exit-code case with exit 3 and the read-once
+  case after 65 polls. The other 52 pass.
+- **The state checked only at timeout:** the new read-once case fails (77 polls),
+  alongside the MERGED read-once case and the `CONFLICTING/DIRTY` exit-code case.
+
 ### The pr-watch ended-PR ordering cases — `scripts/pr-watch-test.sh`
 
 improvise-24lz, found reviewing #253 at `b13355c7`. That head checked `state`

scripts/pr-watch-test.sh

@@ -160,22 +160,22 @@ gap_state "$work/blocked-red" last.json MERGEABLE BLOCKED \
 run_case "a failed required check under MERGEABLE/BLOCKED fails without waiting" 1 \
   "$work/blocked-red" --timeout 0
 
-# improvise-1qaa. A merged PR reports UNKNOWN/UNKNOWN, which was waited on for
-# the full timeout. Each fixture is the shape GitHub returned live (#189, #74).
+# improvise-1qaa/29w2. Each ended fixture is a shape GitHub returned live (#189,
+# #74, #46); the last is the one a waiting loop would sit on.
 # $1 dir, $2 file, $3 head, $4 state, $5 mergeable, $6 mergeStateStatus
 ended() {
   mkdir -p "$1"
   printf '{"headRefOid":"%s","state":"%s","mergeable":"%s","mergeStateStatus":"%s","statusCheckRollup":%s}\n' \
     "$3" "$4" "$5" "$6" "$green_rollup" > "$1/$2"
 }
-for shape in "MERGED UNKNOWN UNKNOWN" "CLOSED CONFLICTING DIRTY"; do
+for shape in "MERGED UNKNOWN UNKNOWN" "CLOSED CONFLICTING DIRTY" "CLOSED MERGEABLE BLOCKED"; do
   set -- $shape
-  d="$work/ended-$1"
+  d="$work/ended-$1-$3"
   ended "$d" last.json aaaaaaaaaaaa "$1" "$2" "$3"
-  run_case "a $1 PR ends the watch as no longer open" 5 "$d" --timeout 5
+  run_case "a $1 PR at $2/$3 ends the watch as no longer open" 5 "$d" --timeout 5
   polls="$(cat "$d/.poll" 2>/dev/null || echo 0)"
-  [ "$polls" = 1 ] && ok "a $1 PR is read once, not waited on" \
-    || bad "a $1 PR is read once, not waited on (polls)" "$polls" 1
+  [ "$polls" = 1 ] && ok "a $1 PR at $2/$3 is read once, not waited on" \
+    || bad "a $1 PR at $2/$3 is read once, not waited on (polls)" "$polls" 1
 done
 
 # improvise-24lz. A merge at a head the watcher never saw is the PR #67 hazard,