use stricter tsconfig's

tsconfig.base.json

@@ -0,0 +1,25 @@
+{
+  "compilerOptions": {
+    // Language
+    "target": "ESNext",
+    "module": "ESNext",
+    "lib": ["ESNext"],
+    "esModuleInterop": true,
+
+    // Module handling
+    "composite": true,
+    "moduleResolution": "bundler",
+    "resolveJsonModule": true,
+    "verbatimModuleSyntax": true,
+    "isolatedModules": true,
+
+    // Linting
+    "noErrorTruncation": true,
+    "strict": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+    "noImplicitOverride": true,
+
+    "outDir": "./node_modules/.cache/tsc_build"
+  }
+}

tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "./tsconfig.base.json",
+  "compilerOptions": {
+    "allowJs": true,
+
+    "lib": ["ESNext", "DOM"]
+  },
+  "include": ["./src"],
+  "references": [{ "path": "./tsconfig.tooling.json" }]
+}

tsconfig.tooling.json

@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.base.json",
+  "compilerOptions": {
+    "checkJs": true
+  },
+  "include": ["./*", "./**/.eslintrc.js"]
+}