Fix types and make sure Typescript types validate

.circleci/config.yml

@@ -44,6 +44,9 @@ jobs:
       - run:
           name: Run Linting
           command: npm run lint
+      - run:
+          name: Check types
+          command: npm run check-types
       - run:
           name: Run Security Check
           command: npm run security

lib/index.d.ts

@@ -10,6 +10,7 @@
 */
 
 import * as postcss from "postcss";
+import * as postcssNode from "postcss/lib/node";
 
 // Even though the concrete classes extend PostCSS classes, we can't extend
 // PostCSS Node types here because they refer to statements that aren't
@@ -26,12 +27,12 @@ export interface NodeBase {
   replaceWith(...nodes: Array<ChildNode | object>): this;
 
   // Inherited from postcss.ContainerBase with no changes.
-  source?: postcss.NodeSource;
-  raws: postcss.NodeRaws;
+  source?: postcss.Source;
+  raws: any;
   toString(stringifier?: Stringifier | Syntax): string;
   error(
     message: string,
-    options?: postcss.NodeErrorOptions
+    options?: postcssNode.NodeErrorOptions
   ): postcss.CssSyntaxError;
   warn(
     result: postcss.Result,
@@ -131,7 +132,7 @@ export type ChildNode =
 
 export type Container = Root | Func | Interpolation;
 
-export interface AtWord extends NodeBase {
+export interface AtWord extends ContainerBase {
   type: "atrule";
   parent: Container;
   name: string;

package.json

@@ -20,6 +20,7 @@
     "ci:coverage": "nyc npm run test && nyc report --reporter=text-lcov > coverage.lcov",
     "ci:test": "npm run test",
     "lint": "eslint lib test --fix --cache",
+    "check-types": "tsc --noEmit",
     "lint-staged": "lint-staged",
     "security": "npm audit --audit-level=moderate",
     "test": "ava"
@@ -48,7 +49,8 @@
     "prettier": "^2.1.2",
     "rewiremock": "^3.14.3",
     "strip-ansi": "^6.0.0",
-    "text-table": "^0.2.0"
+    "text-table": "^0.2.0",
+    "typescript": "^4.2.3"
   },
   "peerDependencies": {
     "postcss": "^8.0.9"

tsconfig.json

@@ -0,0 +1 @@
+{}