build: strictly typecheck the codebase

This change enables TypeScript's strict mode, which allows various bugs to be revealed and shows areas that remain untyped.

As there are many things to fix, I've added an optional step to the CI workflow.

Refs #398, #422

.github/workflows/develop.yml

@@ -26,6 +26,10 @@ jobs:
         env:
           TARGET: 'dev'
 
+      - name: 'Typecheck'
+        run: make typecheck
+        continue-on-error: true
+
       - name: 'Lint'
         run: make lint
 

Makefile

@@ -1,5 +1,5 @@
 .DEFAULT_GOAL: help
-.PHONY: help build run dev prod start logs stop wait-healthy lint format test integration-test smoke-test
+.PHONY: help build run dev prod start logs stop wait-healthy typecheck lint format test integration-test smoke-test
 
 ifeq (${TARGET},)
 TARGET := dev
@@ -46,6 +46,10 @@ endif
 wait-healthy: ## Wait for the app to be healthy
 	@.scripts/wait-healthy.sh prereview
 
+typecheck: export TARGET = dev
+typecheck: build ## Run the typechecker
+	@${DOCKER_COMPOSE} run --rm --no-deps --entrypoint "npm run" prereview typecheck
+
 lint: export TARGET = dev
 lint: build ## Run the linter
 	@${DOCKER_COMPOSE} run --rm --no-deps --entrypoint "npm run" prereview lint

package.json

@@ -13,6 +13,7 @@
     "format": "prettier --ignore-unknown --check '**'",
     "lint": "eslint --ext .js,.jsx,.ts,.tsx .",
     "test": "jest",
+    "typecheck": "tsc --noEmit --project tsconfig.dev.json",
     "build": "rimraf dist && npm run build:scripts && npm run build:backend && npm run build:hooks && npm run build:frontend",
     "build:dev": "rimraf dist && npm run build:scripts && npm run build:backend:dev && npm run build:hooks && npm run build:frontend:dev",
     "build:backend": "parcel build --target=backend --no-optimize src/backend/index.ts && npm run build:templates",

tsconfig.json

@@ -3,7 +3,7 @@
     "module": "commonjs",
     "declaration": true,
     "isolatedModules": true,
-    "noImplicitAny": false,
+    "strict": true,
     "removeComments": true,
     "esModuleInterop": true,
     "allowSyntheticDefaultImports": true,