diff --git a/apps/s03-indexer/README.md b/apps/s03-indexer/README.md
index 7318872..c5a4634 100644
--- a/apps/s03-indexer/README.md
+++ b/apps/s03-indexer/README.md
@@ -36,15 +36,40 @@ bun run --cwd apps/s03-indexer start
 builds the mappings, pulls the required Docker images, and starts the local
 stack.
 
+## Test Runner Conventions
+
+Use the indexer package test script before opening a PR:
+
+```bash
+bun run --cwd apps/s03-indexer test
+```
+
+That command runs `subql codegen`, `subql build`, and then `bun test tests`.
+The codegen step is required in a clean checkout because the mapping sources
+import generated `src/types` models, and those generated files stay ignored.
+
+Use `bun test tests` only for a faster local loop after generated types already
+exist. Keep indexer pure-logic tests on Bun's built-in `bun:test` runner. Use
+Vitest for Vite, DOM, or React/browser harnesses such as `apps/web`; do not move
+indexer mapping tests to Vitest unless they start needing that style of harness.
+
+Current pure-logic test inventory:
+
+- `tests/mappingHandlers.test.ts` stubs SubQuery `store` and `logger`, then
+  covers ScVal decoding, map/vector payload decoding, raw Soroban event
+  decoding, deterministic entity IDs, lifecycle dispatch for market, deposit,
+  withdrawal, order, position, liquidation, ADL, fee, referral, token/faucet
+  events, and unknown-event logging.
+
 ## Local Services
 
 The Docker stack in `docker-compose.yml` starts three services:
 
-| Service | Image/build | Port | Purpose |
-| --- | --- | --- | --- |
-| `postgres` | local `docker/pg-Dockerfile` | `localhost:5432` | SubQuery metadata and indexed entities |
-| `subquery-node` | `subquerynetwork/subql-node-stellar:latest` | internal `3000` | Stellar/SubQuery indexing node |
-| `graphql-engine` | `subquerynetwork/subql-query:latest` | `localhost:3000` | GraphQL API and playground |
+| Service          | Image/build                                 | Port             | Purpose                                |
+| ---------------- | ------------------------------------------- | ---------------- | -------------------------------------- |
+| `postgres`       | local `docker/pg-Dockerfile`                | `localhost:5432` | SubQuery metadata and indexed entities |
+| `subquery-node`  | `subquerynetwork/subql-node-stellar:latest` | internal `3000`  | Stellar/SubQuery indexing node         |
+| `graphql-engine` | `subquerynetwork/subql-query:latest`        | `localhost:3000` | GraphQL API and playground             |
 
 Requirements:
 
@@ -172,11 +197,11 @@ The runner executes layered, timed steps and records each one in a JSON report:
 
 ### Run modes
 
-| Mode | Behavior |
-| --- | --- |
+| Mode                    | Behavior                                                                    |
+| ----------------------- | --------------------------------------------------------------------------- |
 | `--mode auto` (default) | Reuse a complete local deployment if present, otherwise deploy + bootstrap. |
-| `--mode fresh` | Always deploy test tokens, contracts, and bootstrap a market. |
-| `--mode existing` | Require a complete `.deployed/local.env`; fail fast if missing. |
+| `--mode fresh`          | Always deploy test tokens, contracts, and bootstrap a market.               |
+| `--mode existing`       | Require a complete `.deployed/local.env`; fail fast if missing.             |
 
 ### Common options
 
diff --git a/apps/s03-indexer/package.json b/apps/s03-indexer/package.json
index 7e7ae3b..d9d9421 100644
--- a/apps/s03-indexer/package.json
+++ b/apps/s03-indexer/package.json
@@ -14,7 +14,7 @@
     "start:docker": "bun run start",
     "dev": "bun run codegen && bun run build && bun run start",
     "prepack": "rm -rf dist && bun run build",
-    "test": "subql build && bun test tests"
+    "test": "subql codegen && subql build && bun test tests"
   },
   "homepage": "https://github.com/subquery/stellar-subql-starter",
   "repository": "github:subquery/stellar-subql-starter",
@@ -31,7 +31,8 @@
     "@subql/common": "latest",
     "@subql/types-core": "^2.2.0",
     "@subql/types-stellar": "latest",
-    "text-encoding": "^0.7.0"
+    "text-encoding": "^0.7.0",
+    "tslib": "^2.8.1"
   },
   "devDependencies": {
     "@subql/cli": "latest",
diff --git a/bun.lock b/bun.lock
index 62b74ae..05b33b0 100644
--- a/bun.lock
+++ b/bun.lock
@@ -22,6 +22,7 @@
         "@subql/types-core": "^2.2.0",
         "@subql/types-stellar": "latest",
         "text-encoding": "^0.7.0",
+        "tslib": "^2.8.1",
       },
       "devDependencies": {
         "@subql/cli": "latest",