From bead640ab48677141869924466ae4eab9bd9a871 Mon Sep 17 00:00:00 2001 From: Jean-Luc Makiola Date: Sun, 5 Apr 2026 20:12:17 +0200 Subject: [PATCH] docs(phase-19): research reference item model and tags schema Co-Authored-By: Claude Opus 4.6 (1M context) --- .../19-RESEARCH.md | 526 ++++++++++++++++++ 1 file changed, 526 insertions(+) create mode 100644 .planning/phases/19-reference-item-model-tags-schema/19-RESEARCH.md diff --git a/.planning/phases/19-reference-item-model-tags-schema/19-RESEARCH.md b/.planning/phases/19-reference-item-model-tags-schema/19-RESEARCH.md new file mode 100644 index 0000000..3e537e4 --- /dev/null +++ b/.planning/phases/19-reference-item-model-tags-schema/19-RESEARCH.md @@ -0,0 +1,526 @@ +# Phase 19: Reference Item Model & Tags Schema - Research + +**Researched:** 2026-04-05 +**Domain:** Drizzle ORM schema evolution, PostgreSQL migration, service-layer data merging +**Confidence:** HIGH + +## Summary + +Phase 19 transforms the item model from fully self-contained rows to a hybrid model where items can either be standalone (all data on the row) or reference items (pointing at a global catalog entry via `globalItemId` FK). The existing `itemGlobalLinks` junction table is replaced by a direct nullable FK on `items`. A tag system is added for global item discovery. Thread candidates gain the same `globalItemId` FK, and thread resolution creates reference items when the winning candidate has a catalog link. + +The codebase is well-structured for this change. Services are pure functions taking a `db` instance, making the merge-on-read pattern straightforward. The main complexity is ensuring every query path that reads items (7+ locations across item, setup, totals, profile, CSV, and MCP services) correctly joins and merges global item data for reference items. + +**Primary recommendation:** Use a SQL-level `COALESCE` merge pattern in Drizzle queries so that reference items transparently return global data with personal overrides, avoiding application-level merge logic scattered across services. + + +## User Constraints (from CONTEXT.md) + +### Locked Decisions +- **D-01:** Add `globalItemId` (nullable FK to globalItems) directly to the `items` table. When set, the item is a "reference item" -- base data comes from the global item. +- **D-02:** Remove the `itemGlobalLinks` junction table entirely. It was a 1:1 relationship -- a direct FK on items is simpler. Migrate existing link data first. +- **D-03:** Personal fields on items remain: `categoryId`, `notes`, `imageFilename`, `imageSourceUrl`, `quantity`. Add `purchasePriceCents` (nullable integer) for what the user actually paid. +- **D-04:** For reference items, `name`, `weightGrams`, `priceCents` on the items row are kept NULL or empty. The service layer merges global data when returning items. +- **D-05:** Standalone items (no `globalItemId`) continue to work as before -- fully self-contained with all fields populated. This is the "manual entry" path. +- **D-06:** Service layer handles merging transparently. `getAllItems()` and `getItem()` join on globalItems when `globalItemId` is set, returning a unified shape. +- **D-07:** API response shape stays the same as current Item type. Global data fills in name, weight, price, etc. for reference items. +- **D-08:** `productUrl` on reference items: comes from the global item's future `productUrl` field if added, otherwise NULL. +- **D-09:** Add `globalItemId` (nullable FK to globalItems) to `threadCandidates` table. +- **D-10:** Candidates with `globalItemId` display global item data (brand + model as name, weight, price, image). +- **D-11:** Candidates without `globalItemId` work as before (fully manual data). +- **D-12:** When resolving a thread where the winning candidate has `globalItemId`, create a reference item: set `items.globalItemId` = candidate's `globalItemId`, copy only personal fields. +- **D-13:** When resolving a candidate WITHOUT `globalItemId`, behavior stays the same as today -- full data copy. +- **D-14:** New `tags` table: `id` (serial), `name` (text, unique, not null), `createdAt` (timestamp). +- **D-15:** New `globalItemTags` join table: `globalItemId` (FK), `tagId` (FK), composite primary key. Many-to-many. +- **D-16:** Tags are flat -- no type column for now. +- **D-17:** Seed initial tag set via script covering common bikepacking/outdoor gear categories. +- **D-18:** Global item search extends to support tag filtering: `GET /api/global-items?q=...&tags=handlebar-bag,waterproof` returns items matching ALL specified tags. +- **D-19:** Migration script: for each row in `itemGlobalLinks`, set `items.globalItemId = itemGlobalLinks.globalItemId`, then drop `itemGlobalLinks` table. +- **D-20:** Existing items that had links keep their current name/weight/price data populated (not nulled out) -- safe fallback during transition. + +### Claude's Discretion +- Exact seed tag list content and count +- SQL migration ordering (add columns, migrate data, drop old table) +- Whether to update MCP tools in this phase or defer +- Test helper updates for new schema +- Whether global item search uses AND or OR for multiple tags (recommendation: AND -- intersection filtering) + +### Deferred Ideas (OUT OF SCOPE) +- Catalog submission system -- manual items submitted for admin review +- Crowd-sourced purchase price intelligence +- Crowd-sourced weight intelligence +- Admin tag management UI +- Tag type categorization +- Personal weight override field on items + + + +## Phase Requirements + +| ID | Description | Research Support | +|----|-------------|------------------| +| CATFLOW-03 | User can add a catalog item to collection as a reference item with personal fields | Schema: `items.globalItemId` FK + `purchasePriceCents` column. Service: `createItem()` accepts `globalItemId`, stores minimal personal data. | +| CATFLOW-04 | Collection items referencing global items display merged data | Service: `getAllItems()` and `getItemById()` LEFT JOIN on `globalItems`, COALESCE fields. API shape unchanged. | +| CATFLOW-05 | Thread candidates can be added from catalog with global item link | Schema: `threadCandidates.globalItemId` FK. Service: `createCandidate()` accepts `globalItemId`, candidate queries merge global data. | +| CATFLOW-06 | Thread resolution with catalog-linked candidate creates reference item with auto-link | Service: `resolveThread()` branches on `candidate.globalItemId` -- sets FK instead of copying base data. | +| TAG-01 | Tags table seeded with curated tag set for outdoor/adventure gear | Schema: `tags` table. Seed script extends `seed-global-items.ts`. | +| TAG-02 | Global items have multiple tags, searchable and filterable via API | Schema: `globalItemTags` join table. Service: `searchGlobalItems()` accepts `tags` param, filters with subquery. Route: query param parsing. | + + +## Standard Stack + +### Core +| Library | Version | Purpose | Why Standard | +|---------|---------|---------|--------------| +| drizzle-orm | 0.45.2 | ORM for schema, queries, migrations | Already in use, pg-core dialect | +| drizzle-kit | (project dep) | Migration generation | `bun run db:generate` | +| @electric-sql/pglite | 0.4.3 | In-memory Postgres for tests | Already in test infrastructure | +| zod | (project dep) | Schema validation | Already used for all API schemas | + +### Supporting +| Library | Version | Purpose | When to Use | +|---------|---------|---------|-------------| +| @hono/zod-validator | (project dep) | Route-level validation | Tag query param validation | + +No new dependencies are needed. All work uses existing libraries. + +## Architecture Patterns + +### Recommended Migration Order + +The Drizzle migration must be a single SQL file with ordered statements: + +``` +1. ALTER TABLE items ADD COLUMN global_item_id (nullable FK) +2. ALTER TABLE items ADD COLUMN purchase_price_cents (nullable integer) +3. ALTER TABLE thread_candidates ADD COLUMN global_item_id (nullable FK) +4. CREATE TABLE tags +5. CREATE TABLE global_item_tags +6. UPDATE items SET global_item_id = (SELECT global_item_id FROM item_global_links WHERE item_global_links.item_id = items.id) +7. DROP TABLE item_global_links +``` + +Steps 1-5 are schema additions (safe). Step 6 migrates data. Step 7 removes the old table. Drizzle Kit generates steps 1-5 and 7 from schema diff; step 6 must be added manually to the generated migration SQL. + +### Pattern 1: COALESCE Merge for Reference Items + +**What:** Use SQL-level COALESCE to merge global item data into item queries, so the service returns a unified shape regardless of whether an item is standalone or reference. + +**When to use:** Every query that returns items to clients. + +**Example:** +```typescript +// item.service.ts - getAllItems with merge +import { globalItems } from "../../db/schema.ts"; + +export async function getAllItems(db: Db, userId: number) { + return db + .select({ + id: items.id, + name: sql`COALESCE( + CASE WHEN ${items.globalItemId} IS NOT NULL + THEN ${globalItems.brand} || ' ' || ${globalItems.model} + ELSE ${items.name} + END, + ${items.name} + )`.as("name"), + weightGrams: sql`COALESCE( + ${globalItems.weightGrams}, + ${items.weightGrams} + )`.as("weight_grams"), + priceCents: sql`COALESCE( + ${globalItems.priceCents}, + ${items.priceCents} + )`.as("price_cents"), + purchasePriceCents: items.purchasePriceCents, + quantity: items.quantity, + categoryId: items.categoryId, + notes: items.notes, + productUrl: items.productUrl, + imageFilename: sql`COALESCE( + ${items.imageFilename}, + ${globalItems.imageUrl} + )`.as("image_filename"), + imageSourceUrl: items.imageSourceUrl, + globalItemId: items.globalItemId, + createdAt: items.createdAt, + updatedAt: items.updatedAt, + categoryName: categories.name, + categoryIcon: categories.icon, + }) + .from(items) + .innerJoin(categories, eq(items.categoryId, categories.id)) + .leftJoin(globalItems, eq(items.globalItemId, globalItems.id)) + .where(eq(items.userId, userId)); +} +``` + +**Key points:** +- LEFT JOIN on globalItems (null when standalone item) +- COALESCE prefers global data for name/weight/price when globalItemId is set +- Name for reference items is `brand + ' ' + model` from globalItems +- Personal fields (categoryId, notes, quantity, purchasePriceCents) always come from items row +- `globalItemId` is returned in response so client knows it is a reference item + +### Pattern 2: Tag Filtering with Subquery + +**What:** Filter global items by tags using an intersection (AND) subquery pattern. + +**When to use:** `searchGlobalItems()` when `tags` parameter is provided. + +**Example:** +```typescript +export async function searchGlobalItems( + db: Db, + query?: string, + tagNames?: string[], +) { + let baseQuery = db.select().from(globalItems); + + // Text search filter + if (query) { + const escaped = query.replace(/%/g, "\\%").replace(/_/g, "\\_"); + const pattern = `%${escaped}%`; + baseQuery = baseQuery.where( + or(like(globalItems.brand, pattern), like(globalItems.model, pattern)), + ); + } + + // Tag intersection filter (AND logic) + if (tagNames && tagNames.length > 0) { + baseQuery = baseQuery.where( + sql`${globalItems.id} IN ( + SELECT ${globalItemTags.globalItemId} + FROM ${globalItemTags} + JOIN ${tags} ON ${tags.id} = ${globalItemTags.tagId} + WHERE ${tags.name} IN (${sql.join(tagNames.map(t => sql`${t}`), sql`, `)}) + GROUP BY ${globalItemTags.globalItemId} + HAVING COUNT(DISTINCT ${tags.name}) = ${tagNames.length} + )` + ); + } + + return baseQuery; +} +``` + +### Pattern 3: Branched Thread Resolution + +**What:** `resolveThread()` creates a reference item or standalone item based on whether the candidate has `globalItemId`. + +**Example:** +```typescript +// In resolveThread, step 4: +const insertValues = candidate.globalItemId + ? { + // Reference item - minimal data, global link + name: "", // or candidate.name as fallback + globalItemId: candidate.globalItemId, + categoryId: safeCategoryId, + userId, + notes: candidate.notes, + imageFilename: candidate.imageFilename, + imageSourceUrl: candidate.imageSourceUrl, + quantity: 1, + } + : { + // Standalone item - full data copy (existing behavior) + name: candidate.name, + weightGrams: candidate.weightGrams, + priceCents: candidate.priceCents, + categoryId: safeCategoryId, + userId, + notes: candidate.notes, + productUrl: candidate.productUrl, + imageFilename: candidate.imageFilename, + imageSourceUrl: candidate.imageSourceUrl, + quantity: 1, + }; + +const [newItem] = await tx.insert(items).values(insertValues).returning(); +``` + +### All Query Locations Requiring Merge Updates + +Every location that reads items and returns data to clients must be updated to join globalItems: + +| File | Function | Current Pattern | Update Needed | +|------|----------|----------------|---------------| +| `item.service.ts` | `getAllItems()` | Direct select from items | LEFT JOIN + COALESCE merge | +| `item.service.ts` | `getItemById()` | Direct select from items | LEFT JOIN + COALESCE merge | +| `item.service.ts` | `duplicateItem()` | Copies all fields from source | If source has globalItemId, copy globalItemId instead of name/weight/price | +| `setup.service.ts` | `getSetupWithItems()` | Joins items via setupItems | LEFT JOIN globalItems + COALESCE | +| `setup.service.ts` | `getAllSetups()` | Subquery on items for totals | Subquery must COALESCE weight/price from globalItems | +| `profile.service.ts` | `getPublicSetupWithItems()` | Joins items via setupItems | LEFT JOIN globalItems + COALESCE | +| `totals.service.ts` | `getCategoryTotals()` | SUM on items.weightGrams/priceCents | Must COALESCE with globalItems values | +| `totals.service.ts` | `getGlobalTotals()` | SUM on items.weightGrams/priceCents | Must COALESCE with globalItems values | +| `csv.service.ts` | `exportItemsCsv()` | Reads items directly | Must merge global data for export | +| `global-item.service.ts` | `getGlobalItemWithOwnerCount()` | Counts via itemGlobalLinks | Count via `items.globalItemId` instead | +| `thread.service.ts` | `getThreadWithCandidates()` | Reads candidates directly | LEFT JOIN globalItems for candidates with globalItemId | + +### Anti-Patterns to Avoid +- **Application-level merge:** Do NOT fetch items and global items separately then merge in TypeScript. Use SQL COALESCE in the query -- it is more efficient and prevents inconsistency. +- **Nullable name column:** The `items.name` column is currently `NOT NULL`. For reference items, store an empty string or the catalog name as a fallback, but do NOT change the column to nullable -- it would break standalone items and existing queries. +- **Breaking API shape:** Do NOT add a separate `globalItem` nested object to the API response. The merge must be transparent -- clients see the same shape as before, with `globalItemId` as the only new field. + +## Don't Hand-Roll + +| Problem | Don't Build | Use Instead | Why | +|---------|-------------|-------------|-----| +| Data migration | Manual SQL scripts run outside Drizzle | Drizzle migration file with custom SQL | Tracked, versioned, applied via `db:push` | +| Tag intersection query | Nested loops or multiple queries | Single SQL subquery with GROUP BY + HAVING | N+1 queries for tag matching would be very slow | +| Merge logic | TypeScript object spread in every service | SQL COALESCE in query select | Single source of truth, no missed merge points | + +## Common Pitfalls + +### Pitfall 1: Missed Merge Points +**What goes wrong:** Some query path returns raw item data without joining globalItems, so reference items show NULL name/weight/price. +**Why it happens:** 7+ services read items independently, easy to miss one. +**How to avoid:** The "All Query Locations" table above is the complete inventory. Update all of them. Write tests for each that create a reference item and verify merged output. +**Warning signs:** Items showing as unnamed or with zero weight in setups, totals, or CSV export. + +### Pitfall 2: Migration Data Loss +**What goes wrong:** Dropping `itemGlobalLinks` before migrating data to `items.globalItemId`. +**Why it happens:** Drizzle Kit generates "drop table" and "add column" independently. +**How to avoid:** After `db:generate`, manually insert the data migration `UPDATE` statement into the generated SQL file BEFORE the `DROP TABLE` statement. +**Warning signs:** Items that were previously linked show no `globalItemId` after migration. + +### Pitfall 3: NOT NULL Constraint on items.name +**What goes wrong:** Trying to insert a reference item with `name: null` fails because `items.name` is `NOT NULL`. +**Why it happens:** Reference items get their name from globalItems, so there is temptation to leave name null. +**How to avoid:** For reference items, store the brand+model as the `name` value (as a denormalized fallback). The merge query still prefers globalItems data, but the row is valid even without the join. +**Warning signs:** Insert failures on reference item creation. + +### Pitfall 4: Totals Queries Missing Global Data +**What goes wrong:** Setup and global totals report 0 weight/cost for reference items. +**Why it happens:** Totals queries SUM `items.weightGrams` and `items.priceCents` directly without joining globalItems. +**How to avoid:** Update totals subqueries to LEFT JOIN globalItems and COALESCE weight/price values. +**Warning signs:** Setups with reference items showing lower totals than expected. + +### Pitfall 5: Test Sync Calls vs Async +**What goes wrong:** Existing tests for `global-item.service.test.ts` and `global-items.test.ts` use synchronous `.get()`, `.all()`, `.run()` patterns from the old SQLite era. +**Why it happens:** These tests were written before the PostgreSQL migration but never fully updated. +**How to avoid:** When rewriting tests, ensure all database operations use `await` and the async PGlite pattern from `createTestDb()`. The test helper already returns async-compatible db. +**Warning signs:** Type errors about `.get()` not existing, or tests passing but data not actually persisted. + +### Pitfall 6: LIKE Case Sensitivity on PostgreSQL +**What goes wrong:** Tag name matching or global item search becomes case-sensitive. +**Why it happens:** PostgreSQL `LIKE` is case-sensitive (unlike SQLite). The codebase comment says "LIKE is case-insensitive for ASCII" which was true for SQLite but is NOT true for PostgreSQL. +**How to avoid:** Use `ILIKE` (case-insensitive LIKE) for PostgreSQL text search. The current `like()` calls in `searchGlobalItems` should be changed to `ilike()` from `drizzle-orm`. +**Warning signs:** Searches for "revelate" not finding "Revelate Designs". + +## Code Examples + +### Schema Additions (schema.ts) + +```typescript +// Add to items table +export const items = pgTable("items", { + // ... existing fields ... + globalItemId: integer("global_item_id").references(() => globalItems.id), + purchasePriceCents: integer("purchase_price_cents"), + // ... rest of fields ... +}); + +// Add to threadCandidates table +export const threadCandidates = pgTable("thread_candidates", { + // ... existing fields ... + globalItemId: integer("global_item_id").references(() => globalItems.id), + // ... rest of fields ... +}); + +// New tables +export const tags = pgTable("tags", { + id: serial("id").primaryKey(), + name: text("name").notNull().unique(), + createdAt: timestamp("created_at").defaultNow().notNull(), +}); + +export const globalItemTags = pgTable( + "global_item_tags", + { + globalItemId: integer("global_item_id") + .notNull() + .references(() => globalItems.id, { onDelete: "cascade" }), + tagId: integer("tag_id") + .notNull() + .references(() => tags.id, { onDelete: "cascade" }), + }, + (table) => [primaryKey({ columns: [table.globalItemId, table.tagId] })], +); + +// REMOVE: itemGlobalLinks table definition entirely +``` + +### Zod Schema Updates (schemas.ts) + +```typescript +// Update createItemSchema +export const createItemSchema = z.object({ + name: z.string().min(1, "Name is required"), + weightGrams: z.number().nonnegative().optional(), + priceCents: z.number().int().nonnegative().optional(), + categoryId: z.number().int().positive(), + notes: z.string().optional(), + productUrl: z.string().url().optional().or(z.literal("")), + imageFilename: z.string().optional(), + imageSourceUrl: z.string().url().optional().or(z.literal("")), + quantity: z.number().int().positive().optional(), + globalItemId: z.number().int().positive().optional(), // NEW + purchasePriceCents: z.number().int().nonnegative().optional(), // NEW +}); + +// Update createCandidateSchema +export const createCandidateSchema = z.object({ + // ... existing fields ... + globalItemId: z.number().int().positive().optional(), // NEW +}); + +// Update searchGlobalItemsSchema +export const searchGlobalItemsSchema = z.object({ + q: z.string().optional(), + tags: z.string().optional(), // comma-separated tag names +}); + +// REMOVE: linkItemSchema (no longer needed) +``` + +### Seed Tag Data Pattern + +```typescript +// In seed-global-items.ts (or new seed-tags.ts) +const seedTags = [ + // Bag types + "handlebar-bag", "framebag", "saddlebag", "top-tube-bag", + "stem-bag", "fork-bag", "hip-pack", "backpack", + // Shelter + "tent", "bivy", "tarp", "hammock", + // Sleep system + "sleeping-bag", "sleeping-pad", "quilt", "pillow", + // Cooking + "stove", "cookware", "water-filter", "water-bottle", + // Lighting + "headlamp", "bike-light", + // Properties + "ultralight", "waterproof", "budget", "premium", + // Activity + "bikepacking", "hiking", "camping", "touring", +]; +``` + +### Owner Count Migration (global-item.service.ts) + +```typescript +// Updated to use items.globalItemId instead of itemGlobalLinks +export async function getGlobalItemWithOwnerCount(db: Db, id: number) { + const [item] = await db + .select() + .from(globalItems) + .where(eq(globalItems.id, id)); + + if (!item) return null; + + const [result] = await db + .select({ ownerCount: count() }) + .from(items) + .where(eq(items.globalItemId, id)); + + return { ...item, ownerCount: result?.ownerCount ?? 0 }; +} +``` + +## State of the Art + +| Old Approach | Current Approach | When Changed | Impact | +|--------------|------------------|--------------|--------| +| `itemGlobalLinks` junction table | Direct `items.globalItemId` FK | This phase | Simpler queries, fewer joins, cleaner model | +| Separate link/unlink endpoints | `globalItemId` set on item create/update | This phase | Fewer API calls, atomic operations | +| No tag system | `tags` + `globalItemTags` many-to-many | This phase | Enables catalog discovery filtering | +| Full data copy on resolution | Conditional reference vs copy | This phase | Reference items stay in sync with catalog | + +## Open Questions + +1. **MCP Tools Update** + - What we know: MCP tools for items (create_item, update_item, list_items) will need to handle globalItemId. The merge happens at service level so list_items/get_item work automatically. + - What's unclear: Whether create_item MCP tool should accept globalItemId in this phase. + - Recommendation: Defer MCP tool updates. Service-level merge means read operations work automatically. Write operations (creating reference items via MCP) can be added when the catalog UI is ready in Phase 21. + +2. **CSV Export/Import with Reference Items** + - What we know: CSV export reads items and must show merged data. CSV import creates items. + - What's unclear: Should CSV import support creating reference items (by globalItemId)? + - Recommendation: Export shows merged data (transparent). Import creates standalone items only (existing behavior). Reference item creation via import is a future enhancement. + +3. **items.name NOT NULL for Reference Items** + - What we know: `items.name` is `NOT NULL`. Reference items get name from globalItems. + - What's unclear: What to store in `items.name` for reference items. + - Recommendation: Store `"${brand} ${model}"` as a denormalized fallback. This ensures the row is valid standalone and provides a searchable name even without the join. The merge query still prefers globalItems data. + +## Validation Architecture + +### Test Framework +| Property | Value | +|----------|-------| +| Framework | Bun test runner | +| Config file | bunfig.toml (if exists) / package.json scripts | +| Quick run command | `bun test tests/services/item.service.test.ts` | +| Full suite command | `bun test` | + +### Phase Requirements to Test Map +| Req ID | Behavior | Test Type | Automated Command | File Exists? | +|--------|----------|-----------|-------------------|-------------| +| CATFLOW-03 | Create reference item with globalItemId + personal fields | unit | `bun test tests/services/item.service.test.ts -t "reference item"` | Needs update | +| CATFLOW-04 | getAllItems/getItemById return merged data for reference items | unit | `bun test tests/services/item.service.test.ts -t "merged"` | Needs update | +| CATFLOW-05 | Create candidate with globalItemId, merged display | unit | `bun test tests/services/thread.service.test.ts -t "globalItemId"` | Needs update | +| CATFLOW-06 | resolveThread with catalog candidate creates reference item | unit | `bun test tests/services/thread.service.test.ts -t "resolve"` | Exists, needs update | +| TAG-01 | Tags table seeded with curated set | unit | `bun test tests/services/global-item.service.test.ts -t "seed"` | Needs new tests | +| TAG-02 | searchGlobalItems filters by tags (AND logic) | unit | `bun test tests/services/global-item.service.test.ts -t "tag"` | Needs new tests | + +### Sampling Rate +- **Per task commit:** `bun test tests/services/item.service.test.ts tests/services/global-item.service.test.ts tests/services/thread.service.test.ts` +- **Per wave merge:** `bun test` +- **Phase gate:** Full suite green before verification + +### Wave 0 Gaps +- [ ] `tests/services/global-item.service.test.ts` -- must be rewritten for async PGlite (currently uses sync SQLite patterns: `.get()`, `.all()`, `.run()`) +- [ ] `tests/routes/global-items.test.ts` -- must be rewritten for async PGlite (same sync pattern issue) +- [ ] Test helpers may need `insertGlobalItem()` and `insertTag()` async helpers + +## Project Constraints (from CLAUDE.md) + +- **Routing:** TanStack Router with file-based routes. Route tree auto-generated -- never edit manually. +- **Data fetching:** TanStack React Query via custom hooks. Mutations invalidate related query keys. +- **Styling:** Tailwind CSS v4. +- **Schemas:** Zod schemas in `src/shared/schemas.ts` are source of truth for types. +- **Types:** Inferred from Zod + Drizzle in `src/shared/types.ts`. No manual type duplication. +- **Services:** Pure business logic functions that take a db instance. No HTTP awareness. +- **Prices stored as cents** (integer) to avoid float rounding. +- **Timestamps:** stored as timestamps with `defaultNow()`. +- **Testing:** Bun test runner. `createTestDb()` with PGlite + Drizzle migrations. +- **Lint:** Biome (tabs, double quotes, organized imports). +- **Path alias:** `@/*` maps to `./src/*`. + +## Sources + +### Primary (HIGH confidence) +- `src/db/schema.ts` -- Current Drizzle schema, lines 1-220 (PostgreSQL pg-core dialect) +- `src/server/services/item.service.ts` -- Current item CRUD (153 lines) +- `src/server/services/global-item.service.ts` -- Current global item service with link/unlink (76 lines) +- `src/server/services/thread.service.ts` -- resolveThread at line 293 (full data copy pattern) +- `src/server/services/setup.service.ts` -- Setup queries that read items with weight/price +- `src/server/services/totals.service.ts` -- Aggregate weight/cost queries +- `src/server/services/profile.service.ts` -- Public setup item queries +- `tests/helpers/db.ts` -- PGlite test infrastructure +- `drizzle-pg/0001_tough_boomerang.sql` -- Latest migration (created globalItems + itemGlobalLinks) +- npm registry: drizzle-orm@0.45.2, @electric-sql/pglite@0.4.3 + +### Secondary (MEDIUM confidence) +- Drizzle ORM documentation for LEFT JOIN and COALESCE patterns with pg-core + +## Metadata + +**Confidence breakdown:** +- Standard stack: HIGH - no new dependencies, all libraries already in use +- Architecture: HIGH - COALESCE merge pattern is standard SQL, schema changes are straightforward +- Pitfalls: HIGH - identified from direct code analysis of all query locations + +**Research date:** 2026-04-05 +**Valid until:** 2026-05-05 (stable schema, no external dependency changes expected)