fix(work-items): run the create-item sibling check in the linear seed

.changes/work-items/fix-12918-linear-create-item-sibling-check-7c41e2a9.md

@@ -0,0 +1,7 @@
+---
+bump: patch
+---
+
+### Fixed
+
+- `create-item --parent` in the linear seed adapter no longer files a second child with a title the parent already has ([#12918](https://github.com/melodic-software/claude-code-plugins/issues/12918)): when a child with the same trimmed title is open, or was completed or canceled within 24 hours, it creates nothing, exits `0` and prints that child, as the GitHub and local-markdown adapters already do.

plugins/work-items/tools/work-item-tracker/CONTRACT.md

@@ -272,8 +272,9 @@ compare-and-set, so two calls that run at the same moment can still both create.
 parent's sub-issues in the target repository with their `closedAt` in one GraphQL query;
 local-markdown reads each child's `closed_at` frontmatter field, which only the file edit that
 closes the item sets (see "local-markdown adapter"), and a closed child without one counts as
-closed earlier. The linear seed does not run the check yet; the gitea seed refuses
-`--parent`.
+closed earlier. The linear seed reads the parent's `children`, paged, with each child's
+`completedAt` and `canceledAt`, and takes the later one that is set as the close time; a closed
+child with neither counts as closed earlier. The gitea seed refuses `--parent`.
 
 `label-provenance` answers who applied each named label and whether that person may grant
 admission. For every `--label`, the adapter takes the most recent application of that label

plugins/work-items/tools/work-item-tracker/seeds/linear/create-item.sh

@@ -101,6 +101,57 @@ if [[ -n "$BLOCKED_BY" ]]; then
   done
 fi
 
+# Sibling dedupe (CONTRACT.md "Verbs"): a direct child of the parent with the same trimmed
+# title, open or closed within 24 hours, is returned instead of a new issue. The close time
+# is the later of Issue.completedAt and Issue.canceledAt (Linear's schema.graphql); a closed
+# child with neither counts as closed earlier. An open match wins over a closed one. A failed
+# read exits inside wit_linear_gql, so nothing is created on a read that did not complete.
+if [[ -n "$PARENT_UUID" ]]; then
+  CHILD_QUERY='query($id: String!, $first: Int!, $after: String) {
+    issue(id: $id) {
+      children(first: $first, after: $after) {
+        nodes { '"$WIT_LINEAR_ISSUE_FIELDS"' completedAt canceledAt }
+        pageInfo { hasNextPage endCursor }
+      }
+    }
+  }'
+  CHILDREN='[]'
+  CHILD_CURSOR=""
+  while :; do
+    wit_linear_gql "$CHILD_QUERY" \
+      "$(jq -cn --arg id "$PARENT_UUID" --argjson f "$WIT_LINEAR_PAGE_SIZE" --arg a "$CHILD_CURSOR" \
+        '{id: $id, first: $f, after: (if ($a | length) > 0 then $a else null end)}')" \
+      "listing children of $PARENT"
+    CHILD_PAGE="$(jq -c '.issue.children // {nodes: [], pageInfo: {hasNextPage: false}}' <<<"$WIT_LINEAR_DATA")"
+    # Accumulator and page both on stdin. A page of full child nodes can pass the per-argument
+    # exec limit on its own, so neither travels in argv; a failed exec would otherwise drop
+    # children and let a duplicate through.
+    CHILDREN="$(printf '%s\n%s\n' "$CHILDREN" "$CHILD_PAGE" | jq -cs '.[0] + (.[1].nodes // [])')" || {
+      printf 'create-item.sh: could not accumulate the children of %s\n' "$PARENT" >&2
+      exit "$EX_INTERNAL"
+    }
+    [[ "$(jq -r '.pageInfo.hasNextPage // false' <<<"$CHILD_PAGE")" == "true" ]] || break
+    CHILD_CURSOR="$(jq -r '.pageInfo.endCursor // ""' <<<"$CHILD_PAGE")"
+    [[ -n "$CHILD_CURSOR" ]] || break
+  done
+  SIBLING="$(jq -c --arg title "$TITLE" --argjson dt "$WIT_LINEAR_DONE_TYPES" '
+    def trimmed: gsub("^[[:space:]]+|[[:space:]]+$"; "");
+    def is_open: (.state.type // "") as $s | ($dt | index($s)) == null;
+    def closed_at: [.completedAt, .canceledAt] | map(select(. != null)) | max;
+    ($title | trimmed) as $t
+    | [.[] | select(((.title // "") | trimmed) == $t)
+        | select(is_open or (closed_at != null
+            and ((closed_at | sub("\\.[0-9]+"; "") | fromdateiso8601) > now - 86400)))]
+    | (map(select(is_open)) + map(select(is_open | not)))[0] // empty' <<<"$CHILDREN")" || exit "$EX_INTERNAL"
+  if [[ -n "$SIBLING" ]]; then
+    SIBLING_ITEM="$(wit_linear_normalize "$SIBLING")" || exit "$EX_INTERNAL"
+    printf 'create-item.sh: %s already has %s child %s titled "%s"; created nothing\n' \
+      "$PARENT" "$(jq -r '.state' <<<"$SIBLING_ITEM")" "$(jq -r '.id' <<<"$SIBLING_ITEM")" "$TITLE" >&2
+    jq -c --arg p "$PARENT" '. + {parent_id: $p}' <<<"$SIBLING_ITEM"
+    exit 0
+  fi
+fi
+
 # The team's UUID, and the label ids for any requested label names. Linear's
 # IssueCreateInput takes `labelIds`, not names — the same shape trap as Gitea's — so
 # names are resolved here and an unknown one is REFUSED rather than dropped: an item

plugins/work-items/tools/work-item-tracker/seeds/linear/create-item.test.sh

@@ -24,13 +24,32 @@ TEAM_NODE='{"teams":{"nodes":[{"id":"uuid-team-eng"}]}}'
 # pagination/workspace-label cases below for why.
 LABEL_PAGE='{"issueLabels":{"nodes":[{"id":"uuid-label-fix","name":"type: fix"},{"id":"uuid-label-hi","name":"priority: high"}],"pageInfo":{"hasNextPage":false,"endCursor":null}}}'
 
+# seed_create [<children-nodes-json>]: the parent's children answer the sibling check, none by default.
 seed_create() {
   lin_reset
   lin_data 'issueRelationCreate' '{"issueRelationCreate":{"success":true}}'
   lin_data 'issueCreate' '{"issueCreate":{"success":true,"issue":{"id":"uuid-issue-12","number":12,"team":{"key":"ENG"}}}}'
   lin_data 'teams(filter:' "$TEAM_NODE"
   lin_data 'issueLabels(' "$LABEL_PAGE"
   lin_seed_issue 12 started
+  lin_data 'children(' "$(jq -cn --argjson n "${1:-[]}" \
+    '{issue: {children: {nodes: $n, pageInfo: {hasNextPage: false, endCursor: null}}}}')"
+}
+
+# child_node <number> <state-type> <title> [<completedAt>]: a child as the sibling check selects it.
+child_node() {
+  jq -c --arg c "${4:-}" '. + {completedAt: (if ($c | length) > 0 then $c else null end), canceledAt: null}' \
+    <<<"$(lin_issue_json "$1" "$2" "$3")"
+}
+HOUR_AGO="$(jq -rn 'now - 3600 | todate')"
+TWO_DAYS_AGO="$(jq -rn 'now - 172800 | todate')"
+
+assert_no_create() {
+  if [[ "$(lin_requests)" == *"issueCreate"* ]]; then
+    fail "$1" "no issueCreate" "issueCreate issued"
+  else
+    pass "$1"
+  fi
 }
 
 # --- happy path ---
@@ -76,6 +95,102 @@ rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
 assert_eq "create with a parent → exit 0" "0" "$rc"
 assert_contains "parentId is in the create input" "$(lin_bodies)" '"parentId":"uuid-issue-12"'
 
+# --- a same-titled child of the parent is returned, not filed again (CONTRACT.md "Verbs") ---
+# Open, with whitespace around the stored title: the match is exact after trimming both.
+seed_create "[$(child_node 40 started '  child  ')]"
+rc="$(lin_run "$S" --title "child " --parent "linear:acme/ENG#12")"
+assert_eq "open same-titled child → exit 0" "0" "$rc"
+assert_no_create "and no issue is created for an open sibling"
+assert_eq "stdout is the existing child" "linear:acme/ENG#40" "$(jq -r '.id' <<<"$(lin_out)")"
+assert_eq "carrying the parent" "linear:acme/ENG#12" "$(jq -r '.parent_id' <<<"$(lin_out)")"
+assert_eq "as an open item" "open" "$(jq -r '.state' <<<"$(lin_out)")"
+assert_contains "stderr names the child" "$(lin_err)" "linear:acme/ENG#40"
+
+# Closed an hour ago by completedAt: still blocks.
+seed_create "[$(child_node 41 completed child "$HOUR_AGO")]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "child completed 1h ago → exit 0" "0" "$rc"
+assert_no_create "and no issue is created for a recently completed sibling"
+assert_eq "stdout is the closed child" "linear:acme/ENG#41" "$(jq -r '.id' <<<"$(lin_out)")"
+
+# Canceled an hour ago: canceledAt is the close time of the canceled state type.
+seed_create "[$(jq -c --arg c "$HOUR_AGO" '. + {completedAt: null, canceledAt: $c}' <<<"$(lin_issue_json 42 canceled child)")]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "child canceled 1h ago → exit 0" "0" "$rc"
+assert_no_create "and no issue is created for a recently canceled sibling"
+assert_eq "stdout is the canceled child" "linear:acme/ENG#42" "$(jq -r '.id' <<<"$(lin_out)")"
+
+# Completed two days ago, reopened, then canceled an hour ago: the later close time counts.
+seed_create "[$(jq -c --arg d "$TWO_DAYS_AGO" --arg c "$HOUR_AGO" '. + {completedAt: $d, canceledAt: $c}' <<<"$(lin_issue_json 43 canceled child)")]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "child canceled 1h ago after an older completion → exit 0" "0" "$rc"
+assert_no_create "and the older completion time does not let a duplicate through"
+
+# An open match wins over a recently closed one, whatever the order.
+seed_create "[$(child_node 41 completed child "$HOUR_AGO"),$(child_node 40 started child)]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "open and closed siblings → exit 0" "0" "$rc"
+assert_eq "the open sibling is returned" "linear:acme/ENG#40" "$(jq -r '.id' <<<"$(lin_out)")"
+
+# Closed two days ago: does not block.
+seed_create "[$(child_node 41 completed child "$TWO_DAYS_AGO")]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "child completed 2 days ago → exit 0" "0" "$rc"
+assert_contains "and a new issue is created" "$(lin_requests)" "issueCreate"
+assert_eq "returning the new item" "linear:acme/ENG#12" "$(jq -r '.id' <<<"$(lin_out)")"
+
+# Closed with no readable close time counts as closed earlier.
+seed_create "[$(child_node 41 completed child)]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "closed child with no close time → exit 0" "0" "$rc"
+assert_contains "and a new issue is created over it" "$(lin_requests)" "issueCreate"
+
+# A differently titled open child does not block.
+seed_create "[$(child_node 40 started 'other work')]"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "differently titled child → exit 0" "0" "$rc"
+assert_contains "and a new issue is created beside it" "$(lin_requests)" "issueCreate"
+
+# A match on the second children page still blocks: the walk follows endCursor. Routes
+# sharing a pattern are call-ordered, so the second children seeding is page 2.
+CHILDREN_P1="$(jq -cn --argjson n "[$(child_node 40 started 'other work')]" \
+  '{issue: {children: {nodes: $n, pageInfo: {hasNextPage: true, endCursor: "c1"}}}}')"
+CHILDREN_P2="$(jq -cn --argjson n "[$(child_node 44 started child)]" \
+  '{issue: {children: {nodes: $n, pageInfo: {hasNextPage: false, endCursor: null}}}}')"
+lin_reset
+lin_data 'issueCreate' '{"issueCreate":{"success":true,"issue":{"id":"uuid-issue-12","number":12,"team":{"key":"ENG"}}}}'
+lin_data 'teams(filter:' "$TEAM_NODE"
+lin_seed_issue 12 started
+lin_data 'children(' "$CHILDREN_P1"
+lin_data 'children(' "$CHILDREN_P2"
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "same-titled child on page 2 → exit 0" "0" "$rc"
+assert_no_create "and no issue is created for a sibling on a later page"
+assert_eq "stdout is the page-2 child" "linear:acme/ENG#44" "$(jq -r '.id' <<<"$(lin_out)")"
+assert_contains "the second page was requested with the cursor" "$(lin_bodies)" '"after":"c1"'
+
+# Without --parent nothing is read and the item is created as before.
+seed_create "[$(child_node 40 started child)]"
+rc="$(lin_run "$S" --title "child")"
+assert_eq "same title without --parent → exit 0" "0" "$rc"
+assert_contains "creates the item" "$(lin_requests)" "issueCreate"
+assert_eq "returning the new item, not a sibling" "linear:acme/ENG#12" "$(jq -r '.id' <<<"$(lin_out)")"
+if [[ "$(lin_requests)" == *"children("* ]]; then
+  fail "and reads no children" "no children query" "children query issued"
+else
+  pass "and reads no children"
+fi
+
+# A failed children read exits non-zero rather than creating a possible duplicate.
+lin_reset
+lin_data 'issueCreate' '{"issueCreate":{"success":true,"issue":{"id":"uuid-issue-12","number":12,"team":{"key":"ENG"}}}}'
+lin_data 'teams(filter:' "$TEAM_NODE"
+lin_seed_issue 12 started
+lin_seed 'children(' 200 '{"errors":[{"message":"forbidden","extensions":{"type":"Forbidden"}}]}'
+rc="$(lin_run "$S" --title "child" --parent "linear:acme/ENG#12")"
+assert_eq "refused children read → exit 4" "4" "$rc"
+assert_no_create "and nothing is created when the children read fails"
+
 # --- ids are validated and RESOLVED before the item is created ---
 # The links are separate operations, so a bad id found afterwards would leave a created
 # item whose declared relationships were never written — an item that then looks ready.