Make plan

2026-03-07 10:04:03 +01:00 · 2026-03-07 10:04:03 +01:00 · 23a075382f
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+# Testing Strategy
+
+## Layers
+
+### 1. Unit tests (no IO)
+
+Pure logic that can be tested with `cargo test`, no containers needed.
+
+**`hasher.rs`** (already done)
+- Deterministic placement for the same key
+- All volumes appear when requesting full replication
+- Even distribution across volumes
+- Correct key path format
+
+**`db.rs`** (TODO)
+- Open an in-memory SQLite (`:memory:`)
+- Test put/get/delete/list_keys/all_records round-trip
+- Test upsert behavior (put same key twice)
+- Test soft delete (deleted flag)
+- Test bulk_put
+
+**Pure decision functions** (TODO, after refactor)
+- Given a record and a set of healthy volumes, which volume to redirect to?
+- Given fan-out results (list of Ok/Err), which volumes succeeded? Should we rollback?
+- Given current vs desired volume placement, what needs to move?
+
+### 2. Volume client tests (mock HTTP)
+
+Use a lightweight HTTP server in-process (e.g. `axum` itself or `wiremock`) to test `volume.rs` without real nginx.
+
+- PUT blob + .key sidecar → verify both requests made
+- GET blob → verify body returned
+- DELETE blob → verify both blob and .key deleted
+- DELETE non-existent → verify 404 is treated as success
+- Health check → respond 200 → healthy; timeout → unhealthy
+
+### 3. Integration tests (real nginx)
+
+Full end-to-end with Docker containers. These are slower but catch real issues.
+
+#### Setup
+
+```yaml
+# docker-compose.test.yml
+services:
+  vol1:
+    image: nginx:alpine
+    volumes:
+      - ./tests/nginx.conf:/etc/nginx/conf.d/default.conf
+      - vol1_data:/data
+    ports: ["3101:80"]
+
+  vol2:
+    image: nginx:alpine
+    volumes:
+      - ./tests/nginx.conf:/etc/nginx/conf.d/default.conf
+      - vol2_data:/data
+    ports: ["3102:80"]
+
+  vol3:
+    image: nginx:alpine
+    volumes:
+      - ./tests/nginx.conf:/etc/nginx/conf.d/default.conf
+      - vol3_data:/data
+    ports: ["3103:80"]
+
+volumes:
+  vol1_data:
+  vol2_data:
+  vol3_data:
+```
+
+```nginx
+# tests/nginx.conf
+server {
+    listen 80;
+    root /data;
+
+    location / {
+        dav_methods PUT DELETE;
+        create_full_put_path on;
+        autoindex on;
+        autoindex_format json;
+    }
+}
+```
+
+```toml
+# tests/test_config.toml
+[server]
+port = 3100
+replication_factor = 2
+virtual_nodes = 100
+
+[database]
+path = "/tmp/mkv-test/index.db"
+
+[[volumes]]
+url = "http://localhost:3101"
+
+[[volumes]]
+url = "http://localhost:3102"
+
+[[volumes]]
+url = "http://localhost:3103"
+```
+
+#### Test cases
+
+**Happy path**
+1. PUT `/hello` with body `"world"` → 201
+2. HEAD `/hello` → 200, Content-Length: 5
+3. GET `/hello` → 302 to a volume URL
+4. Follow redirect → body is `"world"`
+5. GET `/` → list contains `"hello"`
+6. DELETE `/hello` → 204
+7. GET `/hello` → 404
+
+**Replication verification**
+1. PUT `/replicated` → 201
+2. Read SQLite directly, verify 2 volumes listed
+3. GET blob from both volume URLs directly, verify identical content
+
+**Volume failure**
+1. PUT `/failtest` → 201
+2. Stop vol1 container
+3. GET `/failtest` → should still 302 to vol2 (healthy replica)
+4. PUT `/new-during-failure` → should fail if replication_factor can't be met, or succeed on remaining volumes depending on ring placement
+5. Restart vol1
+
+**Rebuild**
+1. PUT several keys
+2. Delete the SQLite database
+3. Run `mkv rebuild`
+4. GET all keys → should all still work
+
+**Rebalance**
+1. PUT several keys with 3 volumes
+2. Add a 4th volume to config
+3. Run `mkv rebalance --dry-run` → verify output
+4. Run `mkv rebalance` → verify keys migrated
+5. GET all keys → should all work
+
+#### Running integration tests
+
+```bash
+# Start volumes
+docker compose -f docker-compose.test.yml up -d
+
+# Wait for nginx to be ready
+sleep 2
+
+# Run integration tests
+cargo test --test integration
+
+# Tear down
+docker compose -f docker-compose.test.yml down -v
+```
+
+The integration test binary (`tests/integration.rs`) starts the mkv server
+in-process on a random port, runs all test cases sequentially (shared state),
+then shuts down.
+
+### 4. What we don't test
+
+- Performance / benchmarks (follow-up)
+- TLS, auth (not implemented)
+- Concurrent writers racing on the same key (SQLite serializes this correctly by design)
+- Blobs > available RAM (streaming is a follow-up)